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Guide to Extendingyour Home
A Ten Alps Publication
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CLI VE WOODWARDCLI VE WOODWARDb u i l d i n g s e r v i c e sb u i l d i n g s e r v i c e s
Building Work
Carpentry
Refurbishment
Extensions
Roofing
t . 0 1 8 6 5 3 6 1 7 2 5
m . 0 7 7 1 1 6 5 6 2 3 7
Low er Fa rm, Low er Roa d,
G a rs ing ton, Oxford OX44 9DP
Fascias Soffits Bargeboard
Claddings Window Boards Interior Trims Foiled Pro files
We also supply products for the following:
Gutters Drainpipes
Drainage Window Ancillaries Conservatory Roofing
A Walker UPVC LimitedRadley Road Industrial Estate, AbingdonOxfordshire OX14 3SB
Tel: 01235 537590 Fax: 01235 537591
ww w.awalkerupvc.com Email: sales@ awalkerupvc.com
A. WALKER
UPVC LTD.
CHILTON WASTE SERVICES
01235 831913
www.chiltonwasteservices.co.uk
One c all away from a fast,
pro fessional service
Skip Hire Roll-on-off Containers Grab & Delivery Service
Crushed Hardcore Screened Soil and Wood Chippings
Licensed Tipping Recycling
Waste Transfer and Inert Landfill
weprovide..
.
wesell...
wedo
...
Tim WiddowsonPerspective Artist Painter
Architectural and Interior Visualisation
Landscapes
Mallard Reach, High Street, Long Wittenham,Oxon OX14 4QQ
Tel: 01865 407757 [email protected]
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South Oxfordshire & Vale of White Horse Guide to Extending Your Home 1
Contents
3 Introduction11 Domestic Extensions25 Loft Conversions34 Garage Conversions39 Domestic Cellar Conversions43 Other Alterations46 Radon
This publication is available as an E-book: www.extendingyourhome.com/valeofwhitehorse
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2 South Oxfordshire & Vale of White Horse Guide to Extending Your Home
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Background
Your home is likely to beone of your biggest assets,it is a major long-terminvestment and over thecourse of your occupancyyour home will have to
adapt to the changing needsof you and your family.
Within England and Walesmost construction work iscovered by the BuildingRegulations. These areminimum technicalstandards set by thegovernment and all but the
most minor building workcarried out must conform tothese standards.
The standards cover manyaspects of health and safetywithin buildings as well asenergy consumption andaccessibility. The BuildingRegulations are detailedtechnical standards set to
ensure that the buildingstock within England andWales is built to areasonable standard andthat it meets the needs ofthe population.
The Building Regulationsare minimum standards,they do not cover quality of
workmanship beyond thatrequired to ensure the basicsafe construction of thebuilding. It is possible
therefore that a buildingwhich complies with theBuilding Regulations maynot meet the finishingstandards that you requireand you should be mindfulof this when you are
entering into contractualarrangements with yourbuilder.
There is a legal requirementon both the builder and theowner of the building tomake an appropriateBuilding RegulationsApplication and to complywith the BuildingRegulations. Failure to do socan result in prosecutionthrough the MagistratesCourt.
Purpose of this Guide
This guide will take youthrough the BuildingControl process.
It is not a substitute forprofessional advice but itaims to show how yourproject will be affected bythe Building Regulations.The guide is divided intochapters that contain adviceabout typical buildingprojects and it is hoped thatwhen you have read the
guide you will have a betterunderstanding of what isinvolved in a domesticbuilding project.
Introduction
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4 South Oxfordshire & Vale of White Horse Guide to Extending Your Home
Br i ckw ork con t rac to rs
A&D Construction and Sons Ltd. are a Swindon based, famil y managed business specialisi ng inbrickwork and scaffolding services to house bui lders, com mercial developers and privateindividuals.
Establi shed in 1997 by Anthony Humphreys from a single bri cklaying team, A& D Constructionhave grown consistently over the years.
With over 80 bricklayers and stonemasons employedA&D Construction work with cli ents such as TaylorWimpey Oxfordshire, Taylor Wimpey Bristol, NorwestHolst Limited, ISG Pearce, McClaren, David WilsonHomes (Southern). We have also recently com pletedlarge comm ercial projects such as CirencesterLeisure Centre and the B& Q Superstore at Barnfield ,Swindon and the im pressive mixed use developm entfor Norwest Holst in Winchester.
At A& D Construction our reputation for excellenceand integrity and quality workmanship i s extremelyim portant to us. As a truly fami ly run business (withAnthony and wife Dawn heading the business, plusfour sons and their wives and partners involved) it isdefini tely a matter of famil y pride! As a result of ourfocus on attention to detail we have won numerousBrickwork awards.
In 2001 we introduced a scaffolding service into ourbusiness to provide our clients with a single poi nt ofcontact for both project elements leading to improved coordination and programm ing and greaterproject efficiency. Click A& D Scaffolding for more details. Our scaffolding service can work jointlywith our bricklaying division or can be c ontracted separately if required.
A&D Scaffolding
Supplying Scaffolding for : Single house builds
S ma ll/spe cia lis t hous ing
developments
La rg e hous ing
de velopment projec ts
Commercia l, industria l
and retail developments
Local Authority projects
Tel /Fax: 017 93 78 31 90
Emai l: enquir ies@ aanddconstructi on.co.uk www.aanddconstruction.co.uk
A&D Const ruc t ion & Sons LT DPe nnyhooks Farmhouse, S hrivenham, Nr Swindon S N6 8EX
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Domestic projects thatmay require BuildingRegulations consentinclude:-
Extensions
Garage conversions
Loft conversions
Cellar conversions
Structural alterations e.g.removing load bearingwalls
Alterations to drainage,hot water or heating
systems New or replacement
windows
Electrical work
Replacement roofcoverings
Cavity wall insulation
Some garages
Some conservatories
If you are considering abuilding project and you areunsure as to whether it willrequire Building Regulations
consent please feel free tocontact us and we will behappy to advise you.
The BuildingRegulations Process
If your project needsBuilding Regulationsconsent you will need tomake a BuildingRegulations application.
How to Proceed
Unless you are experiencedin construction you willneed to get some
professional advice. Thereare a number of ways ofobtaining this including:
1. Appointing an architect/technician or buildingsurveyor: these willprepare drawings anddesigns for yourproposal, obtain the
necessary approvals andif required they will alsohelp you to find asuitable builder andmanage the projectfor you.
2. Appointing a design &build company: thesecompanies offer a onestop shop forconstruction projects,their design department
will prepare thenecessary drawings andobtain the necessaryapprovals and theirconstructiondepartments willtranslate these drawingsinto reality.
3. Using an experienced
builder: some buildershave experience incarrying out domesticprojects and may beable to offer you apackage similar to thedesign & buildcompanies.
Making a Building
RegulationsApplication
There are two ways ofmaking a BuildingRegulations application:-
Full Plans Application
This is often thought of asthe traditional way ofapplying for BuildingRegulations Approval. Thebuilding designer will drawup detailed plans andsupporting information forthe proposed scheme andwill send them to ustogether with an applicationform and the necessary fee.We will then check the
details and following anynecessary consultations andliaisons with the buildingdesigner a Building
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South Oxfordshire & Vale of White Horse Guide to Extending Your Home 7
Regulations Approval willbe issued.
Work can start any timeafter the application hasbeen received although it iswise to wait until the
scheme has had its initialcheck under the BuildingRegulations, this usuallytakes between two andthree weeks.
Our team of surveyors willliaise with your builder andinspect the work in progresson site. When the project is
satisfactorily completed aBuilding RegulationsCompletion Certificate willbe issued showing that theproject has beenindependently inspectedand that it complied withthe Building Regulations.
Building Notice
ApplicationThis system is best suited tosmall projects carried out bya competent builder and isnot recommended unlessyour builder and designerare very experienced in thetype of project that you areundertaking and are fullyaware of the requirements
of the Building Regulations.Under this scheme noformal Approval of plans isissued and work is approvedon site as it progresses.
To use the Building Noticeprocess you or your agentwill need to submit aBuilding Notice applicationform together with a sitelocation plan and therequired fee. Work can
commence 48 hours afterthe notice has beenaccepted.
When work commences oneof our surveyors will meetwith your builder to discuss
your intentions, to agreehow the work should becarried out, agree when thework will need to beinspected and to establishwhether any furtherinformation will be requirede.g. structural calculationsor drawings.
When the project issatisfactorily completed aBuilding RegulationsCompletion Certificate willbe issued showing that theproject has beenindependently inspectedand that it complied withthe Building Regulations.
The forms for making a
Building Regulationsapplication can be obtainedby telephoning or calling intoour offices, or can bedownloaded from our websitewww.whitehorsedc.gov.uk
Self Certification
To help you to gain BuildingRegulations approval more
easily the government haveallowed certain trade bodiesto self certify theirmembers work and to issueBuilding Regulationscertificates. Currently thebodies which can issuethese certificates are:-
1. FENSA Contractorsregistered with FENSAcan issue certificates forreplacement windows.
2. CERTASS Contractorsregistered with CERTASScan issue certificates forreplacement windows.
3. GAS SAFE Registeredcontractors can issue
certificates forinstallations andalterations to gas, hotwater and heatingsystems so long as thecontractor is aregistered installer andnot just a serviceengineer.
4. OFTEC RegisteredOFTEC installers canissue certificates forinstallation of andalteration to oil burningboilers and appliances.
5. HETAS RegisteredHETAS installers canissue certificates forinstallation of andalteration to solid fuelburning boilers andappliances.
6. Part P ElectricalContractors registeredunder one of the Part Pschemes can issuecertificates for domesticelectrical work.
Tips for using SelfCertified Contractors
1. Always ensure thecontractor is registeredfor the work they areundertaking, eg. If youare having a newheating system installedensure the contractor isa registered installer nota service engineer.
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8 South Oxfordshire & Vale of White Horse Guide to Extending Your Home
D.
E.R. LO
NGD.
E.R. LO
NG& SON& SONB u i l d er & D eco r a t o r
Groundwork Extensions
Roofing Brickwork
Plastering & Rendering Carpentry
Patio Design Wood Decking
Interna l & External Dec oration
Oxford
739657
Mobile
07860 866329
Oxford
739657
Mobile
07860 866329
Al l Enquiries Welcome
Firm Quotati ons Given On Request
Fax: 01865 739657
18 Sandleigh Road, Dry Sandford,
Nr. Abingdon, Oxon OX13 6DP
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South Oxfordshire & Vale of White Horse Guide to Extending Your Home 9
2. Always ensure that atthe end of the job thecontractor issues youwith a Certificateconfirming that the workcomplies with the
Building Regulations,you may need this whenyou come to sell yourproperty.
3. If you are in any doubtabout anything eithercontact the relevanttrade association orcontact Vale of WhiteHorse Building Controlfor advice.
Other Permissions youmay Require
Planning Permission: manydomestic alterations will alsorequire Planning Permission,further advice is availablefrom the Planning Portal
www.planningportal.gov.ukor to confirm whetherPlanning Permission will berequired for your projectplease either contact one ofour Planning Officers on:North Team 01235 540347,South Team 01235 540348or download and complete
the householder enquiryform from our websitewww.whitehorsedc.gov.uk
Party Wall Act: if yourproposal affects a Party Wallor if you will need to
excavate foundations closeto your neighbours houseyou may need to give themnotice under the Party WallAct. This is a Civil Act andVale of White Horse DistrictCouncil do not have anyenforcing power under theAct. Further details of thiscan be found on thePlanning Portalwww.planningportal.gov.ukor contact us for the latestguide to the Party Wall Act.
The InspectionProcess
Whatever type of projectthat you are undertaking we
will arrange to carry out aseries of inspections of thework in progress. Whilst wecannot be on site all of thetime the inspections will becarried out at key stages sothat we can be reasonablysure that the work carriedout complies with the
Building Regulations.We will tailor theinspections carried out tosuit your individual projectand we will generallyarrange these inspections
with your builder. If duringthe project you have anyconcerns, if you wantsomething specificinspecting, or if you wouldlike to meet to discuss anyissues please contact usand we will make thenecessary arrangements.
CompletionCertificates
When your project has beensatisfactorily completedunder the BuildingRegulations we will issue aCompletion Certificate. Thisis a legal document that youwill need if you want to sell
your house, you may alsoneed it for re-mortgaging orinsurance purposes.Please ensure that we arecalled in to carry out ourfinal inspection at the endof the project to ensure thatyour Completion Certificateis issued.
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South Oxfordshire & Vale of White Horse Guide to Extending Your Home 11
Domestic
ExtensionsIntroduction: if you needmore space and you do notwant to move house youmay wish to considerextending your home. Yourhome is probably your mostvaluable asset so it is
important that yourextension project iscarefully planned. Thisguide is not a substitute forprofessional advice but hasbeen written to provide you
with useful information
about how the Building
Regulations will affect
your extension.
Suitability: most houses are
suitable for extending,
providing that you have the
space. When you are
thinking about whether your
house is suitable for
extending you might like to
consider:
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12 South Oxfordshire & Vale of White Horse Guide to Extending Your Home
Wiltshire Woodworking is a com pany specialising in dom estic carpentry and joinery but also working withinthe com mercial and industrial sector throughout Oxfordshire and the surrounding counties.
Wiltshire Woodworking has developed soli d custom er relationships, providing q uality workmanship by aqualified and experienced carpenter and joiner. Please take time to look at the gallery page on our website
where you can view a small selection of j obs undertaken by Wiltshire Woodworking.
If you require more information, or wish to request a free no obligation quote, please dont hesitatein contacting us.
Broad Street , Uf f ington, Oxfordshire, SN7 7RA0 7 7 7 1 9 5 3 8 0 3 0 1 3 6 7 8 2 0 4 6 2 j a m ie @wi l t sh ir e wo od wo r k i ng .co . uk
Glenn Whi t eCarpentry & Building
7 Hobbyhorse Lane, Sutton C ourtenay
Abingdon, O xfordshire O X14 4BB
Tel: 07934 617250 Email: glennwhite@ hotmail.co.uk
Wiltshire WoodworkingDom estic a nd Comm ercia l Ca rpent ry & Joinery
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1. How will you accessyour extension?
2. What effect will yourextension have on thecirculation in andaround your home?
3. What effect will yourextension have on yourexisting house andgarden? Will it block out
light from existingrooms or make somerooms unusable? Willyou still be able to getinto your garden?
4. Is your existing housebuilt from an unusualconstruction forexample prefabricatedpanels, concrete frameetc?
If you can resolve all ofthese issues then your
house may well be suitablefor extending.
How to Proceed: extensionsare complex projects andunless you are experiencedin construction you will
need to get someprofessional advice. Theintroduction containedadvice about obtaining thisand with this in place wecan now consider some of
the technical issues thataffect domestic extensions.
Technical Issues
Foundations: thefoundations are one of themost important parts ofyour extension and oftenone of the most expensive.For domestic extensionstrenchfill foundations arethe most common, theseshould be taken down intofirm natural ground andshould generally be aminimum of 1m deep. Inareas with clay subsoil treesup to 20m away can have asignificant effect on
foundations which generallymeans that they need to bedeeper, sometimes as deepas 2.5m. If you areconcerned about any trees
Certain ground conditions will affect the ground floor detail
South Oxfordshire & Vale of White Horse Guide to Extending Your Home 13
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14 South Oxfordshire & Vale of White Horse Guide to Extending Your Home
Electrical Test & Certification Re-wires Part or Complete
Electrical Showers Complete Portable Appliance Testing
Extra Power or Lighting Points
Fire Intruder Alarms
J .M.Const ruc t ion
13 Cherry Tree Road, Chinnor, Oxfordshire OX39 4QYTel/Fax: 01884 353888 Email: [email protected]
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South Oxfordshire & Vale of White Horse Guide to Extending Your Home 15
please get in touch with usand we will give you someadvice regarding foundationdepths.
Ground Floor: the groundfloor of your extensionperforms a number of tasks:it must support the floorloading, keep out damp andprovide thermal insulation.Generally a ground floor is amultilayer structure, the topsoil under the extensionfloor area is removed and a
layer of compacted stone isplaced over the site. This isblinded with sand and alayer of 1200g polythene isthen placed over the sandand lapped in with thedamp proof course in thewall (in certain areas,especially in the north andwest of the County, it may
be necessary to protect thedevelopment from radon, anaturally occurring radioactive gas, by the
installation of a suitablemembrane at floor level.With the closure of manymines in the south eastSTYTHE gas and Methaneprotection will also berequired, as a 1200gpolythene barrier will notprovide adequateprotection, if in doubtcontact your local areaoffice). A layer of insulationis then provided and aconcrete slab at least
100mm thick is poured overthe insulation.The concrete can either befloat finished or a screedapplied at a later date. Onsome sites where theground floor is significantlyhigher than external groundlevel or where the site hasbeen affected by trees, a
suspended floor may beneeded, these can beformed from either concreteor timber and if you need
any guidance regardingsuspended floors, pleaseget in touch with us foradvice.
Walls: the walls of yourextension must carry theloads from the floors androof, keep the weather outof the extension and providethermal insulation. Cavitywalls are commonly usedfor domestic extensions.These are made up frombricks and blocks and the
cavity is filled withinsulation as the workproceeds. When buildingwalls remember to ensurethat you have adequatebuttressing at the corner ofyour extension, lintels overall openings, wall ties tojoin the leaves of your cavitywall together and a suitable
damp proof course. If youare building up against yourneighbours house you willalso need to ensure that
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16 South Oxfordshire & Vale of White Horse Guide to Extending Your Home
Peewit Farm95 Drayton Road
Sutton Courtenay, AbingdonOxfordshire OX14 4HBTel: 01235 531238
Email: [email protected]
Glenbury
Construction
Rober t
HamletBuilders
17 Ma nor Fa rm Roa d
Horspath, Oxford
OX33 1SD
E: rob ertha mlet@ hotmail.co .uk
Tel:0 1 8 6 5
8 7 2 8 7 0
DAVID COOKSLEY
ASSOCIATES
Architects & Project M anagers
Bui ldin g plans drawn an d local authority
consents sought for :
Extensions & Alterations
Individual Houses
Conversions
Refurbishments
Commercial
Listed Bui ldings
Town Planning Consultants
D esign & Bui ld Project Co-ordination
Expert Witness
Excel Studios
24A Gatehampton RoadGoring-on-Thames,Reading RG8 0EP
Tel/Fax: 01491 872306Mobile: 07789 938291Email: [email protected]
Abingdon-on-Thames
Telephone: 01235 559129
Mobile: 07940451268
Roofing & PropertyMaintenance
22 Crosslands DriveAbingdon
Oxfordshire OX14 4JS
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your wall provides adequatesound resistance.
First Floor: two storeyextensions will require afirst floor, these aregenerally made up from
timber floor joists whichspan between load bearingwalls, they support floorboarding above andplasterboard is then fixed tothe underside of the joiststo provide a ceiling finishand fire resistance. The sizeof the floor joists willdepend on the span so
please contact us for adviceon the joist size required.The floor will also need toinclude sound insulationand in domestic extensions,100mm of sound deadeningmineral wool placedbetween the joists isgenerally sufficient.
The Roof Structure: the roofof your extension will needto be designed to keep outthe rain and snow and mayneed to cope with somelight loft storage loading.Generally two types of roofare used for domesticextensions:-
Flat Roofs: this is the
simplest type of roofstructure and for someextensions, generally singlestorey, a flat roof canprovide a practical andeconomic solution.Timber joists are used tospan between theloadbearing walls andbeams and these are
covered with a plywooddecking laid on firring stripsto provide a fall. Thermalinsulation is then placed
over the roof and it isgenerally finished with awaterproof covering of threelayers of bonded roofingfelt. Critical things toconsider in this type of roof
are the size and support ofthe roof joists and the waythat the roof will beinsulated and, if necessary,ventilated.
Pitched Roofs: if a flat roof isnot suitable for your needsyou are likely to require apitched roof. These aregenerally more substantialstructures that are finishedwith roof tiles or slates.The supporting structure ofthe roof can be formed intwo ways:
1. Trussed Rafter Roofs:these are quick toconstruct,measurements are taken
from site and roof
trusses are made up in afactory, they are thendelivered to site readyfor installation. Eachroof is individuallydesigned by the roof
truss manufacturerusing specialistcomputer software andthe carpenters time onsite can be significantlyreduced.
2. Traditional Roofs:A carpenter cuts atraditional roof on site.The roof structure willgenerally be designedby an Architect orStructural Engineer andthe timber is thendelivered to site wherethe carpenter will setout the roof and cuteach of the individualtimbers to size before
installing them.
South Oxfordshire & Vale of White Horse Guide to Extending Your Home 17
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18 South Oxfordshire & Vale of White Horse Guide to Extending Your Home
Acorn
CarpentryLimited
Carpenters &J oiners
Harwell Innovation CentreBuilding 173, Curle AvenueHarwell International Business CentreDidcot, Oxon OX11 0QG
Telephone: 01235 838570Fax: 01235 838571Email: [email protected]
Building & RenovationServices
Evergreens, All Saints Lane,
Sutton Courtenay,
Abingdon, Oxon OX14 4AG
Tel: 01235 847577
M ob: 07774 114309
All building work undertaken Extensions
Renovations
New Build
Trained Carpenters
Established over 30 years
Dom J arman
Architect
Designs and drawings prepared for
alterations, extensions andnew building work.
Planning, listed building,
conservation area and building
regulations applications submitted.
Friendly, reliable, professional
service.
Woodbury, High Street,
Long Wittenham,
Oxon OX14 4QH
[email protected]. 01865 407416
M&A ELECTRICALS30 Market Place,Wantage,Oxfordshire OX12 8AJFax-01235 762304
Tel-01235 762468
www.electricianoxford.co.uk
Electrical ContractorsRegistered ECA Electricians since 1985.
Your local Electrician since 1963.All Types of Work Undertaken.Portable Appliance Testing.
Electrical Goods & AccessoriesAn extensive range of goods and appliances stocked.Extension Leads, Torches, Batteries, Sockets andSwitches etc.
Lighting ShowroomWe have accounts with most lighting companies andhave access to all types of lighting.The showroom is now spread over two floors.
Lamps [Light bulbs]A large selection always in stock-if we cannotsource your lamp its not available!
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This type of roof offersthe greatest flexibility inroof shape and is oftenthe only way of roofingcomplicated extensionsespecially where the
new roof must join ontoan existing structure.
The size of the timbers andsupporting beams requiredin a roof will depend on theloadings and spans involvedin each case, complex roofswill require a StructuralEngineers design but our
Building Control Surveyorswill be happy to assist yourbuilder in designing simpleroof structures.
Once the support is in placethe roof must be covered toprovide weather protection,pitched roofs are generallyfinished with tiles or slateswith a layer of roofing
membrane or felt underthem. The tiles aresupported by the rafters viaa series of timber battens.To provide adequateweather resistance the
tiles overlap each otherand they must have anadequate pitch.For extensions it is commonto use tiles or slates thatmatch the main housealthough this is not alwayspossible if the extensionroof has a very low pitch.Our Building Control
Surveyors will be happy toassist you with anyenquiries that you haveabout roof finishes.
Stairs: if your extension hasmore than one storey youmay need to install astaircase and careful designof this can be critical to thesuccess of the extension.
If a stair is installed it shouldbe designed in accordancewith the following guidance.
Width: there is no minimumwidth for stairs in theBuilding Regulations
however they will need tobe useable. Generally stairsare 8501000mm wide.
Pitch: the maximum pitchfor the stair should notexceed 42 degrees.
Rise and Going: themaximum rise of each treadof a domestic stair should
not exceed 220mm and thegoing should be at least220mm.
Headroom: the clearheadroom over thestair should be atleast 2m.
Handrails and Balustrades:the stair should be providedwith a handrail at least
900mm high and anyexposed edges of stairs orlandings should be providedwith balustrading at least900mm high.
Fire Precautions: it isimportant that you considerfire precautions when youare designing your
extension. The mostdangerous fires generallyoccur at night wheneveryone is asleep and togive you awareness of a firethe Building Regulationssuggest that mainsoperated smoke detectorsshould be installed on eachfloor of the house when it
is extended.To prevent people beingtrapped by a fire all roomsthat do not open directly
South Oxfordshire & Vale of White Horse Guide to Extending Your Home 19
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20 South Oxfordshire & Vale of White Horse Guide to Extending Your Home
W. A. HINE& SON LT DBUILDERS & CONTRACTORS
Est 1955
33 Wallingford RoadGoring, Reading
Berkshire RG8 0HLTel: 01491 872433
Email: [email protected]
B&BBUILDERS
6 All Saints Court
Didcot
OXON
OX11 7NG
Tel:
0 1 2 3 5 2 0 0 6 3 1
At New Looks we have severalservices available. Our aim is tobring you the most cutting edgein design. New products fromQUOOKER, FRANKIE,THERMASKIRT and CROWN
show our commitment to this.
Products:
Kitchens UPVC Windows & Doors Granite/Composite and Laminate worktops Built in appliances Heated skirting Boiling water taps
Services:
Kitchen installation Kitchen design and project management Full range of building services available UPVC Window & Door installation On site granite worktop measure and templates
133 Brasen ose Road, Didcot OX11 7BP
Tel: 01235 511155 Emai l : info@new look s.org.ukWeb: w w w.new looks.org.uk
New Looks Kitchens
Gary B yrneGB
P a i n t e r s& D e c o r a t o r s2 4 Ye a r s E x p e r i e n c e
Domestic & Commercial
Competitive Prices
No Job Too Small
All Out of Hours Work Carri ed Out
Mobi le : 07 75 9 34 15 25Tel /Fax: 012 35 84 72 78
gary.byrne@ hotmail.co.uk
24 Bradstocks Way, Sutton Courtenay,Abingdon OX14 4BY
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South Oxfordshire & Vale of White Horse Guide to Extending Your Home 21
onto a hall and all first floorrooms should have awindow or door that is largeenough for people to escapethrough. If you are using awindow as your secondary
fire escape it should have aclear opening of at least0.33m2 at least 450mm widewith a cill height of between800 and 1100mm abovefloor level.
Fire is a very dangerousthing and careful designand planning are required to
ensure that the risks itposes are minimised.
Ventilation: fresh air isessential to healthy livingand the BuildingRegulations require yourextension to have adequateventilation, generally anopening window with atrickle vent is all that is
required, the windowshould have an openablearea equivalent to at least1/20th of the floor area ofthe room that it isventilating. The trickle ventis a small slot type vent thatyou can leave open to allowsome backgroundventilation without the needto open the window,generally these are found inthe top of the windowframe. If your extensioncontains a kitchen, utilityroom or bathroom you willneed to provide an extractfan in these areas and yourBuilding Control Surveyor
will be pleased to provideyou with more detailedadvice when they callon site.
Drainage: it is usuallypossible to connectdrainage from extensionsinto the existing drainagesystems. Drainage can bedivided into two types, foul
water and rainwater andgenerally speaking thedrainage systems should bekept separate. Foul drainageis generally dischargedthrough a series of pipesand manholes to a publicsewer although someproperties will have septictanks or private sewage
treatment plants. Whenplanning your extensionlook for manholes and tryand find out where yourdrains are running so thatyou can work out how anynew drains will connect tothem. It is important that allnew underground drainpipes have a diameter of at
least 100mm so that they donot block or freeze, arewatertight and havemanholes or access pointsso that any blockages canbe cleared. Where possiblerainwater drainage shouldnot be discharged to foulsewers as this can causeproblems with flooding, the
preferred solutions are todischarge rainwater tosoakaways located in yourgarden at least 5m from anybuilding or to storm watersewers if they are available.
Heating: most extensionswill need to be heated andyou will need to check with
your heating engineer thatyour existing system hassufficient capacity to heatyour extended house.
You may also need tomove your boiler, if forexample, your extensionwill cover the flue outlet.Any alterations to yourheating system should be
carried out by a suitablyqualified plumber orheating engineer registeredwith Gas Safe for gas firedboilers or OFTEC for oil firedboilers. Any new boilers willneed to be highly efficientcondensing boilers and thenew radiators that youinstall in your extension
should be fitted withthermostatic radiatorvalves so that you canensure that they useheat efficiently.
Thermal Insulation:CO2 emissions are a majorconcern in todaysenvironment and you willneed to provide a high levelof insulation within yourextension. Your extensionshould provide an insulatedenvelope so that the amountof heat escaping isminimised. The roof, wallsand floors of your extensionshould all include thermalinsulation; walls generally
have insulation placed withinthe cavity, roofs generallyhave insulation in the loftarea and sheets of insulationcan be placed beneath theconcrete of your ground floor.
Another major area whereheat is lost from buildings isthe windows and theserequire special attention:
24mm double glazing unitsincorporating low emissivityglass are generally requiredand, unless energy
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improvements are carriedout in the existing house,the window area of yourextension is limited by theBuilding Regulations to 25%of the floor area plus thearea of any existing
openings covered by theextension.
High levels of insulation canresult in problems withcondensation and care mustbe taken to ensureadequate ventilation isavailable to rooms andparticularly in roof voids.
As well as insulating yourextension you will need toconsider the efficiency ofany services you put into it.
Low energy light fittingsshould be used wherepossible and any newheating systems shouldwork to high levels ofefficiency and have suitablethermostats and controls.
Sound Insulation: to reduceunwanted noise the wallsand floor around bedroomswill need to be insulated toreduce sound transmission,this is generally achieved byplacing 100mm of sounddeadening quilt in the floorvoid and in the partitionsaround the bedrooms.
Electrical Installations: aspart of the BuildingRegulations process you will
need to supply BritishStandard Test Certificatesfor most new electricalinstallations, whenselecting your electricalcontractor please ensure
that they are competent toprovide you with these testcertificates as otherwiseyou are likely to incuradditional costs for testingthe circuits.
Glazing: to reduce the riskof people injuringthemselves, glazing in and
around doors and all glazingwithin 800mm of floor levelshould be either toughenedor laminated glass.
Conclusion: whereas a welldesigned and constructedextension is a definite assetto your home that canprovide useful extra space
and add value to yourproperty, a poorly thought-out extension can reduceyour propertys value and insome cases compromiseyour safety and thestructural integrity of yourhome. It is important toensure that you plan your
extension carefully and getthe work carried out by anexperienced contractor.
The Building Regulationsexist to ensure thatbuildings are constructed toa reasonable standard;Building Control will bepleased to provide you with
any further assistance thatyou require during thedesign and construction ofyour extension.
South Oxfordshire & Vale of White Horse Guide to Extending Your Home 23
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24 South Oxfordshire & Vale of White Horse Guide to Extending Your Home
Tel: 01491 613066
Email: [email protected]
Web: www.dparchitects.co.uk
FMB Member
General Building Works
Extensions
Refurbishments
Loft Conversions
Commercial And Domestic
Garden Walls
Repairs
New Builds
Are you considering extending your house?Then Tamdrew Builders Ltd has a selectteam of builders available to assist you withanything you require. Highly trained buildersare available to answer all your houseextensions questi ons.
Unit 3, 21 Singers LaneHenley on Thames
Oxfordshire RG9 1HBT: 01491 576761F: 01491 575277E: tamdrewbuilders@ btconnect.com
With over 21 years experience SL White Carpentryand Joinery Ltd offer high quality craftsmenservices to the Oxfordshire and surrounding area.
Our Services include:
I ExtensionsI General BuildingI KitchensI BathroomsI ConservatoriesI Bespoke JoineryI Loft ConversionsI Decking and LandscapingI Fencing and Gates (Iron/Timber)I Property DevelopmentI Restoration and Renovation work
We also offer a design assistance service free of charge.
For more information or a free no
obligation quote please call Simon on:01235 764116 / 07737 203762www.slwhite.co.uk
Mark BurkeProperty Maintenance
28 Wick Green, Grove, Wantage OX12 0AS
Telephone: 07515658391
01235201129email: [email protected]
Windows, Doors and
Conservatories
Quality and HonestyQuality and Honesty
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Loft Conversions
Introduction: most houseshave a large space undertheir roofs normallyknown as the loft or attic,this space is often underutilised and in someinstances can offer an ideal
opportunity for expandingyour home. This guide hasbeen written to provide youwith useful informationabout how the BuildingRegulations will affectyour loft conversionproject.
Suitability: not all lofts aresuitable for conversionand as a first step it is wiseto go into your loft and carryout a brief survey beforeyou get too far into theplanning of your project.When carrying out yoursurvey check:
That there is enoughheight within your loft tostand comfortably,bearing in mind thatyour new floor is likelyto be around 200mmhigher than your
existing ceiling joists. That the loft space is
large enough to providea useable room.
That there arent anychimneys or servicespassing through the loftspace that will needmoving.
That your roof has feltunder the tiles or is fullyweathertight.
If the answer to all of thesequestions is Yes then yourloft may well be suitable forconversion.
South Oxfordshire & Vale of White Horse Guide to Extending Your Home 25
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26 South Oxfordshire & Vale of White Horse Guide to Extending Your Home
Graham
Smith
Associates
1 Rose Tree Cottages
Stoke Ro w, H enley-on-Tha mes
Oxford shire RG9 5PN
Tel: 01491 681721
gr aham .smith@ rosetree.freeserve.co.uk
Structural Eng ineersStructura l Engineers
Planning Assistance
For Personal & Professional
Assistance in
Land & Planning Matters
Contact
As s o c i a t e sLand, Devel opment & Property Consultants
01235 832867
www.stewartlilly.co.uk
Stewart Lil l y
Building cont ractor of fering:
New Builds
Extension s & Alt eration s
Carpent ry & Join eryPlum bing & Heating
Electrical Work
Painting & Decorating
Tot al Pro ject M anag em ent Service
Tel: 01865 823301
Mobile: 07970 62 42 52Email: [email protected]
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South Oxfordshire & Vale of White Horse Guide to Extending Your Home 27
How to Proceed: loftconversions are complexprojects and unless you areexperienced in construction
you will need to get someprofessional advice. Theintroduction containedadvice about obtaining thisand with this in place wecan now consider some ofthe technical issues thataffect loft conversions.
Technical Issues
The Roof Structure: the roofof your home is currentlydesigned to keep out therain and snow and to copewith some light loft storageloading. After a loftconversion your roof willhave to cope withsignificantly different
loadings, a new floorstructure will be requiredand it is likely that a numberof the structural elements
will need to be altered toallow for circulation withinthe room, roof windows etc.Roofs can generally bedivided into two types.
Trussed Rafter Roofs: thesehave been common sincethe 1970s, and roofs of thistype are difficult to convert.Roof trusses are complexpieces of engineering andthey should not be alteredwithout the advice of a
structural engineer. Whenconverting this type of roofit is common for a series ofbeams to be installed toprovide support to the newfloor and to strengthen therafters, this allows thebracing sections of thetrusses to be cut out tocreate a clear floor area.
Traditional Roofs: these aregenerally made up from aseries of rafters and purlins
spanning between loadbearing walls. These roofsare less complicated toconvert than Trussed RafterRoofs, however, beams areoften required to providesupport to the new floorstructure and the existingpurlins and a StructuralEngineers design will berequired for all but thesimplest conversions.
When considering a loft
conversion dont betempted to simply boardover your existing ceilingjoists and rafters, this canadversely affect the value ofyour property and in somecircumstances can causeoverloading and endangerthe structural stability ofyour home.
Accessing your LoftConversion: if you want toconvert your loft for
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28 South Oxfordshire & Vale of White Horse Guide to Extending Your Home
Sonya
GoodwinPlastering
No job too small
01491 65149207899 756434
CLIVE COLLETT(Electrical) Ltd
Thistled ow n - The S q ua re
Brightwell-Cum-Sotwell
Wa lling ford - Oxon OX10 0S B
Tel/Fa x: 01491 835988
Installation Maintenance
I nspection
All types of Electrical Installation
P eriod ic Inspe ction Repo rts
Domestic
Commercial
Industrial
Free quotationsNo call out fee
All domestic plumbing carri ed out
Manor Farm,
West Hagbourne
Didcot OX11 0ND
Contact Matt
07816399315
01235 [email protected]
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South Oxfordshire & Vale of White Horse Guide to Extending Your Home 29
habitable use you will needto install a staircase andcareful design of this can becritical to the success ofyour conversion.If there is enough headroom
it is often best to continuethe stair in the existingstairwell as this saves spaceand gives a feeling ofcontinuity within the home,alternatively part of a roomwill have to be partitionedoff to accommodate the newstaircase. Wherever the stairis installed it should be
designed in accordance withthe following guidance.
Pitch: the maximum pitchfor the stair should notexceed 42 degrees.
Rise and Going: themaximum rise of each treadof a domestic stair shouldnot exceed 220mm and the
going should be at least220mm.
Headroom: the clearheadroom over the stairshould be at least 2m, forsome loft conversions theBuilding Regulations allow areduced headroom of 1.9mover the centre of the stair
and 1.8m on the outsideedge.
Handrails and Balustrades:the stair should be providedwith a handrail at least900mm high and anyexposed edges of stairs orlandings should be providedwith balustrading at least900mm high.
For loft conversions wherespace is very limited andonly one room is created,
a specialist alternatingtread staircase can be used,these are steeper thanstandard stairs and canprovide valuable space insome circumstances.
Fire Precautions: housefires can kill and fireprecautions are a major
concern for the BuildingRegulations. The mostdangerous fires generallyoccur at night wheneveryone is asleep and togive you awareness of a fireit is important that youinstall smoke detection.When converting your loftyou will need to ensure thatyou have mains powered,interlinked smoke detectorsin the hall/landing areas onevery floor of your house.
Two Storey Houses: theBuilding Regulationsrequirements for fireprecautions in two storeyhousing are quite simple as
it is generally felt that if youcouldnt get out down thestairs you could jump or berescued from a first floor
window. If you areconverting the loft of abungalow you will need toensure that you have mainspowered interlinked smokedetection at ground and firstfloor level and that allhabitable rooms at firstfloor level have an escape
window.Escape Windows: as theirname suggests, arewindows that are largeenough to allow people toescape or be rescuedthrough them. They needto have a clear opening areaof at least 0.33m2 and a
clear width of at least450mm. The bottom of theopening light should be nomore than 1100mm abovefloor level and they shouldallow people to escape to aplace free from danger.Escape windows need to befitted with escape hingesthat allow the window to
fully open. Some of thestandard hinges fitted toUpvc windows do notachieve this so it is wise to
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30 South Oxfordshire & Vale of White Horse Guide to Extending Your Home
Buil ding ServicesStephen Tobin Mob: 07717 375190
We provide complete Building Services to include:
New-buildsExtensions Conversions
Renovation & repair workKitchens BathroomsPlumbing CarpentryElectrical Plastering
Windows & Doors Tiling
We can p roject manage all of your works
requirements
Call or emailStephen Tobin Mob: 07717 375190
Take a look at some previous works:
www.rsbuildingservices.com
Wantage, Oxfordshire
Hopes Design Services Ext ens io ns
New Build
Renova t ions
Condit ion s urveysfor domest ic &
public pr ojec t s
S pecialis t in des ign for
s pecia lis t needs
inc luding dis a bled
fac ilit y gra nt s
Va rious levels of s er vice s offere d from
s upplying ba s ic pla ns for pla nninga nd building r eg ula t ion a pproval,
t hrough t o full project ma nag ement
Qualified Architectural Technician
Cont a c t : G r a ha m Ho pes
Telephone/Fa x: 0 1 8 6 5 7 3 5 4 6 6
Email: ma il@ hopes des igns ervices .co . uk
Web: ww w.hopesdes igns ervices .co .uk
Creative BrickworkBUILDING CONTRACTORS
All Building Work Undertaken
Extensions . Patios
Garden Walls . Re-pointing
17 Grunsell Close, Headington
Oxford OX3 9QQ
Telephone: 01865 751035
Mobile: 07734 706714www.creativebrickwork.net
CONSTRUCTION LTD
Master CraftsmanBuilders of Distinction
Tel: 01491 629110
Fax: 01491 628947
Grange Farm, BadgemoreHenley-on-Thames
Oxon RG9 4NZ
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South Oxfordshire & Vale of White Horse Guide to Extending Your Home31
check this with your glazingsupplier when you orderyour windows.
Three Storey Houses: whenyou convert the loft of ahouse and create a thirdfloor the BuildingRegulations require you tolook at the fire precautionswithin the house a lot moreseriously. Mains operatedsmoke detection needs tobe fitted to give youawareness of a fire and as,due to the height of yournew floor, you can no longerrely on escaping throughthe windows the only safe
way out of the house isdown the stairs. It istherefore vital that the stairis protected from fire. Toprotect the stair all of thedoors that open onto thestair need to be half hourfire doors and the stairshould end up in a hall witha door direct to the outside.
Generally, unless a sprinklersystem or alternativeescape stair is provided,stairs cannot discharge into
other rooms in three storeyproperties.
Four Storey Houses: if yourhouse already has threestoreys, loft conversionsbecome more complicated.
You are likely to need toinstall a sprinkler system ora second escape stair andthe project will needspecialist design. Pleasecontact us and we will behappy to provide you withmore detailed advice if youare considering one of theseprojects.
Fire is very dangerous andcareful design and planning
is required to ensure thatthe risks it poses areminimised.
Bathrooms: it is often a niceidea to include a bath orshower room in your loftconversion, the best placefor this is generally directlyabove your existing
bathroom as this shouldensure that you can connectinto the existing drainageand water supplies without
the need for excessivepipework. Any bath orshower rooms will also needto be fitted with an extractfan to improve ventilation.It is a good idea to decide
on the location of anybathrooms at an earlystage in your spaceplanning process.
Thermal Insulation: CO2emissions are a majorconcern in todaysenvironment and you willneed to provide a high level
of insulation to your roof aspart of your loft conversion.The most common way ofachieving this is to place ahigh performance insulationboard in between and belowthe rafters. Unless your roofhas a breathable felt youwill need to leave a voidabove the insulation and
ensure that you haveeffective roof ventilation toprevent the build upof condensation.
Sound Insulation: to reduceunwanted noise the wallsand floor around bedroomswill need to be insulated toreduce sound transmission,
this is generally achieved byplacing 100mm of sounddeadening quilt in the floorvoid and in the partitionsaround the bedrooms. If youare converting the loft of asemi-detached or terracedproperty you will need toensure that the sound
resistance of the Party Wallis upgraded so that soundtransmission to yourneighbours is reduced.
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32 South Oxfordshire & Vale of White Horse Guide to Extending Your Home
MYERSPLASTERING
For a Free Quotation contact
Dave on 0 7771537 36 4
4 1HAMBLE ROAD, DIDCOT, OXON
Domestic & CommercialComplete Inter ior & Ext er ior
Renovations
Skimming Rendering Pebbledash Screeding Metal Fix Ceilings
Metal Stud Work Plasterboarding Coving
All a spe cts of Ca rpentry and Building wo rk
Commercial or Domestic
Large Carpentry only Contracts
Extens ions , Reno vations , Kitchens
Dam p P roofing &Ge nera l Ma intenance
P roject Ma nag ement
CSCS Registered, Fully Insured
Free Quote &Expert Advice
Tel /Fax : 01 23 5 81 94 04
M o b: 0 7 8 7 0 6 4 7 9 7 0
www.n jscons t ruc t ion .co .ukDidcot, Oxford
CARPENTRY AND BUILDI NGCONTRACTS
WHATEVER YOUR PROJECT,WE HAVE THE CONTACTS AND ADVICE YOU NEED
PLANNING PERMISSION
BUILDING REGULATIONS
CONTRACTOR SEARCH
www.homeandbuild.co.ukFor more information 0845 652 4124
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South Oxfordshire & Vale of White Horse Guide to Extending Your Home33
Heating: to maximise theusability of the room youwill probably want to installheating, in most instancesthe most effective way ofdoing this is to extend the
existing central heatingsystem. You will need tocheck with your plumber orheating engineer to ensurethat your existing boiler hassufficient capacity to serveany additional radiators andany new radiators should befitted with thermostaticvalves to control the room
temperature.If it is not possible to extendthe existing system or if youprefer an alternativemethod of heating, e.g.electric panel heaters,careful consideration shouldbe given as to how thesecan be switched andcontrolled to ensure that
they function efficiently.
Electrics: you are likely torequire some electricalalterations as part of yourconversion. Depending onthe age and condition ofyour existing electricalsystem it is sometimespossible to extend existing
circuits but sometimes newcircuits and even a newdistribution board will berequired. It is a good idea toget advice from a competentelectrician at an early stage.
When appointing anelectrician please ensurethat they are able to issueyou with BS7671 testcertificates when they havecompleted their installationas these will be requiredbefore your BuildingRegulations CompletionCertificate can be issued
and you will incur additionalcosts if the test certificateshave not been provided.
Windows and Ventilation:any new habitable roomswill need to be ventilated.Generally this is achieved byproviding an openingwindow or roof light
equivalent to 1/20th of thefloor area of the room with atrickle vent at high level. Allnew windows must be fittedwith highly efficient doubleglazed units.
In bath or shower rooms anextract fan should be fittedand in rooms without
opening windows extractfans should be fitted thatare triggered by the lightswitch with overrun timersthat allow the fan toremain on after the light is
turned out.
Conclusion: a wellconverted loft is a definiteasset to your home, it canprovide useful extra spaceand add value to yourproperty. However a poorlyconverted loft can reduceyour propertys value and in
some cases compromiseyour safety and thestructural integrity of yourhome. It is important toensure that you plan yourconversion carefully and getthe work carried out by anexperienced contractor.
The Building Regulations
exist to ensure thatbuildings are constructed toa reasonable standard; Valeof White Horse BuildingControl will be pleased toprovide you with any furtherassistance that you requireduring the design andconstruction of your project.
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Introduction: if you needmore space and you do notwant to move house youmay wish to considerconverting your garage.
Your home is probably yourmost valuable asset so it is
important that yourconversion project iscarefully planned. Thisguide is not a substitute forprofessional advice but hasbeen written to provide youwith useful informationabout how the BuildingRegulations will affectyour conversion.
Suitability: if you have abrick or block garageattached to your house it isprobably suitable forconverting. When you arethinking about whetheryour garage is suitable forconversion you might liketo consider:
Whether there are anyknown problems withyour garage, are thereany cracks in it? Is itdamp? Does the roofleak? Has the floorbeen contaminatedwith fuel or oil?
How will you get intothe new room? Have
you got or can you puta doorway through tothe garage from thehouse?
Will you have enoughparking and storagearea if you convert yourgarage?
Is there enough roomin your garage toprovide the
accommodation thatyou require or wouldyou be betterextending theproperty?
Is your existing garagebuilt from an unusualconstruction? Forexample, prefabricated
panels, concrete frameetc.
If you can resolve all ofthese issues then yourgarage may well besuitable for conversion.
How to Proceed: garageconversions can becomplex projects and
unless you are experiencedin construction you willneed to get someprofessional advice. Theintroduction containedadvice about obtaining thisand with this in place wecan now consider some ofthe technical issues thataffect garage conversions.
Technical Issues
Infilling the Garage DoorOpening: this tends to be
Garage
Conversions
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South Oxfordshire & Vale of White Horse Guide to Extending Your Home35
Before After
the most visible part of your
conversion from the outsideand whatever you choose to
infill the opening it will need
some support. Some
garages have a foundation
that runs across the garage
opening which you can use
to support your infill.
Unfortunately the only real
way to tell if the front ofyour garage has an existing
foundation is to dig a hole
and find out.
If there is no foundation
under your garage door
opening there are two main
options. You can either:
1. Dig a foundation 1m deep
or to the same depth as thefoundations of the existing
garage, call us to inspect
the foundation and then fill
it with concrete.
Or
2. If the opening is only the
width of a single garage
door install two 150mmdeep concrete lintels across
the opening supported by
the existing foundations.
Your Building Control
Surveyor will be happy toprovide you with moreadvice about which is thebest option for you when weget to site.
With the foundations inplace the garage dooropening can now be filledin. There are several options
for how this can be done.The opening can be filled inwith brickwork to match thehouse and a window. Peoplegenerally narrow the garagedoor opening slightly as afull width window canappear out of proportion.To keep the damp out and toprovide insulation it is best
to use a cavity wall and yournew window should bedouble-glazed. Otheroptions include installing alightweight timber framedpanel with a weatherproofexternal surface andinsulation, this can bequicker and cheaper andhas the advantage that it is
easier to remove if you, orany future owners of thehouse, ever wanted toreinstate your garage.
Whichever option you
choose it is important thatthe infill panel providesadequate weatherresistance and insulationand that all of the new workis tied into the existingconstruction. Your BuildingControl Surveyor will behappy to provide you withadvice about this.
Raising the Floor Level:garage floors are generallylower than the floor in themain house and they oftenslope towards the garagedoor. For these reasonsgarage floors are generallyraised as part of aconversion. There are two
main ways of raising agarage floor. Whichever wayyou choose it is importantto consider insulation anddamp proofing.
Option 1: Concrete: usingthis method a polythenemembrane is placed overthe garage floor, floor
insulation is laid down,a second polythenemembrane is installed andthe floor level is brought up
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36 South Oxfordshire & Vale of White Horse Guide to Extending Your Home
to the same level as thehouse using concrete orsand and cement screed.
Option 2: Timber: thismethod involves placingtreated timber floor joistsonto a damp proofmembrane placed over theexisting concrete floor,placing floor insulationbetween the joists andcovering the floor joists withfloor boards or tongued andgrooved chipboard.
The floor can then be
finished with carpet,laminate or any otherdecorative surface.
Lining the External Walls:the walls used to constructgarages are not normally upto habitable standards, theyare sometimes formed froma single thickness of
brickwork and even whenbuilt from cavity masonrythey are often uninsulated.When converting yourgarage the walls will needto be upgraded.
There are three main areasof concern when upgradingwalls in a garageconversion: weather and
damp resistance, insulationand sound resistance. Theupgrading scheme that youchoose will be influenced bythe original construction ofyour garage walls, these canbe broadly divided into twocategories.
Cavity Walls: if your garage
is built from cavity walling,weather resistance anddamp proofing areunlikely to be a problem.
These walls generally havedamp proof courses andproviding that your wall is ingood condition and is notshowing signs of wateringress or rising damp, the
wall will simply requireinsulating and a plasterfinish ready for yourdecoration. There are twooptions for insulating thewall: either the cavity canbe injected with cavitywall insulation or aninsulated lining board canbe fixed to the inner face of
the wall prior to plasterboarding or plastering.Various boards are availableand your Building ControlSurveyor will be happy toprovide advice as to whichboards are suitable foryour project.
Solid Brick Walls: ingarages these are generallyonly a single brickapproximately 100mm thickand they often haveintermediate piers that
buttress the walls and givethem additional strength.A single brick wall will notprovide adequate weatherresistance to a habitableroom and a supplementarywall will need to beprovided behind the originalwall. This can be doneeither by building an
additional skin of masonryto form a cavity wall, thecavity can be insulated asthe wall is built, and thewall can then be dry lined orplastered. Alternatively anindependent timber framedwall can be constructed with
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South Oxfordshire & Vale of White Horse Guide to Extending Your Home37
a cavity between the new
framing and the existingwall. The frame should beconstructed from treatedtimber and insulationshould be provided betweenthe timber studs. Once theframe is in place aninsulated plasterboardfinish can be applied readyfor decoration.
Occasionally garages arebuilt with 225mm thick solidbrick walls. If they are ingood condition and have adamp proof course they willnormally provide adequateweather resistance but theywill need to be lined with aninsulating board to improvetheir insulation.
Party Walls: if any of thewalls of your garage areshared with a neighbour it is
considered to be a Party
Wall. These walls will needto be upgraded to reducesound transfer betweenyour new room and yourneighbours property. YourBuilding Control Surveyorwill be happy to provide youwith advice as to how youcan upgrade anyParty Walls.
The Ceiling: unless yourexisting garage has anadequate ceiling you willneed to provide one as partof your conversion.Plasterboard is the mostcommon material used forceilings as it offers good fireresistance and flame spread
properties. Other materialscan be used but they willgenerally need to be treatedto improve their fire
performance. If the garage
is open to a roof you willneed to provide insulationabove the ceiling and theroof void will generally needto be ventilated above theinsulation to reduce the riskof problems withcondensation. In a pitchedroof fibreglass insulationwill normally suffice but
with flat roofs, where spaceis confined, highperformance insulationboards are often required.
Your Building ControlSurveyor will be happy todiscuss this with you.
Heating: to maximise theusability of the room you
will probably want to installheating; in most instancesthe most effective way ofdoing this is to extend the
Certain ground conditions will affect the ground floor detail
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38 South Oxfordshire & Vale of White Horse Guide to Extending Your Home
existing central heatingsystem. You will need tocheck with your plumber orheating engineer to ensurethat your existing boiler hassufficient capacity to serve
any additional radiators andany new radiators should befitted with thermostaticvalves to control the roomtemperature. If it is notpossible to extend theexisting system, or, if youprefer an alternativemethod of heating, e.g.electric panel heaters,
careful consideration shouldbe given as to how thesecan be switched andcontrolled to ensure thatthey function efficiently.
Drainage: if you are lookingto include a sink, bathroom,shower room or cloakroomin your conversion it is
important that you considerdrainage at an early stage.Any new appliances willneed to connect to yourexisting foul drainagesystem as they are notallowed to be connectedinto rainwater drains. Whenplanning your layouts makesure that there are suitable
routes for pipes to run to apoint where they canconnect to existing drains.
Windows and Ventilation:any new habitable roomswill need to be ventilated.Generally this is achieved byproviding an openingwindow equivalent to
1/20th of the floor area ofthe room with a trickle ventat high level. All newwindows must be fitted with
highly efficient doubleglazed units and it is wise tomake sure that they containan opener with a clear areaof at least 0.33m
2
and450mm wide which should
be large enough for you toescape through in the caseof fire. This is essential ifthe door out of your garageopens into a room otherthan your entrance hall.Special fire escape hingesshould be fitted to thiswindow to ensure that it canbe fully opened if you ever
need it. In bath or showerrooms an extract fan shouldbe fitted and in roomswithout opening windowsextract fans should be fittedthat are triggered by thelight switch with overruntimers that allow the fan toremain on after the light isturned out.
Fire Precautions: when youare investing money in yourhome it is a goodopportunity to review thefire precautions that areavailable in the existinghouse. Mains operatedsmoke detectionsignificantly improves fire
safety in the home and theBuilding Regulationsrequire that it should beinstalled where garages areconverted to habitablerooms.
Electrics: you are likely torequire some electricalalterations as part of your
conversion. Depending onthe age and condition ofyour existing electricalsystem it is sometimes
possible to extend existingcircuits but sometimes newcircuits and even a newdistribution board will berequired. It is a good idea toget advice from a competent
electrician at an early stage.When appointing anelectrician please ensurethat they are able to issueyou with BS7671 testcertificates when they havecompleted their installationas these will be requiredbefore your Building
Regulations CompletionCertificate can be issuedand you will incur additionalcosts if the test certificateshave not been provided.
Conclusion: a well designedand constructed garageconversion can be a definiteasset to your home that canprovide useful extra spaceand add value to yourproperty. A poorly thought-out conversion can reduceyour propertys value and insome cases compromiseyour safety and thestructural integrity of yourhome. It is important toensure that you plan your
conversion carefully and getthe work carried out by anexperienced contractor.
The Building Regulationsexist to ensure thatbuildings are constructed toa reasonable standard; Valeof White Horse BuildingControl will be pleased to
provide you with any furtherassistance that you requireduring the design andconstruction of your project.
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Introduction: if you are
fortunate enough to have a
cellar beneath your house
and you need more space
you may wish to consider
converting your cellar. Your
home is probably your most
valuable asset so it isimportant that your
conversion project is
carefully planned. This
guide is not a substitute for
professional advice but has
been written to provide you
with useful information
about how the Building
Regulations will affect yourconversion.
Suitability: if you have a
cellar beneath your house it
may well be suitable for
converting. When you are
thinking about whether your
cellar is suitable for
conversion you might like toconsider:-
Is there sufficientheadroom in the cellar,bearing in mind that theceiling and the floortreatments that you will
have to install are likelyto reduce the availableheadroom?
Does the cellar everflood?
What is the access like?Is there a place for astaircase?
Will you have enough
storage area if youconvert your cellar?
Is there enough room inyour cellar to providethe accommodation thatyou require or wouldyou be better extendingthe property?
Domestic Cellar
Conversions
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Is there any ventilationto your cellar or couldany be provided?
If you can resolve all ofthese issues then yourcellar may well be suitablefor conversion.
How to Proceed: Cellarconversions can be complexprojects and unless you areexperienced in constructionyou will need to get someprofessional advice.The introduction containedadvice about obtaining this
and with this in place wecan now consider some ofthe technical issues thataffect cellar conversions.
Technical Issues
Lowering the Cellar Floor:if there is not sufficientheadroom in your cellar it issometimes possible to
lower the cellar floor. This isnot however a simpleoperation and carefulconsideration needs to begiven to whether loweringthe floor will undermine thehouse or the neighbourshouse foundations andwhether the floor will endup below the water table
and make the property morevulnerable to flooding.Specialist advice shouldalways be taken beforeconsidering loweringcellar floors.
Waterproofing: as mostcellars are set within theground they tend to suffer
from problems with damp.If it is to be converted to ahabitable room your cellarwill need to be damp
proofed. A number ofsystems are available fordamp proofing cellars andmost of them use aproprietary waterproofrender system known as
tanking. This is applied sothat it forms a continuousdamp proof layer across thefloor and up the walls and isgenerally installed byspecialist companies whowill offer an insurancebacked guarantee for theinstallation. Protecting yourcellar from damp is animportant part of the cellarconversion process and wewill need to approvedetails of the system thatyou are using and theinstaller prior toinstallation.
Access: some cellarsalready have good stepped
access to them, whether theexisting stairs will providesuitable access to ahabitable room is a matterof judgment and ourBuilding Control Surveyorswill be happy to offeradvice. If there are no steps,or if the existing steps areinadequate, a new stair willneed to be installed. Carefulconsideration should begiven to the best locationfor the stair and this will beinfluenced by a number offactors including the layoutof the existing house andcellar, the headroomavailable and whether a
secondary means of escapecan be provided from thecellar area. Wherever thestair is installed it should be
designed in accordance withthe following guidance.
Pitch: the maximum pitchfor the stair should notexceed 42 degrees.
Rise and Going: themaximum rise of each treadof a domestic stair shouldnot exceed 220mm and thegoing should be at least220mm.
Headroom: the clearheadroom over the stairshould be at least 2m, forsome loft conversions theBuilding Regulations allow areduced headroom of 1.9mover the centre of the stairand 1.8m on the outsideedge.
Handrails and Balustrades:the stair should be providedwith a handrail at least900mm high and any
exposed edges of stairs orlandings should be providedwith balustrading at least900mm high.
Fire Precautions: your cellarwill need to be providedwith suitable escape routesin case of a fire. If yourcellar has a light well it may
be possible to upgrade thisso that as well as providingventilation to the room itcan provide a secondary fireescape. To be considered asa secondary fire escape itwould need to be fitted witha door or window with aclear area of at least 0.33m
2
and 450mm wide. Special
fire escape hinges shouldbe fitted to this window toensure that it can be fullyopened if you ever need it
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South Oxfordshire & Vale of White Horse Guide to Extending Your Home 41
and you should be able toeasily climb up from thelight well to ground level.If you cannot provide asecondary fire escape thestaircase will need to end
up in a fire protectedhallway with a door directto outside.
When converting your cellarit is a good opportunity toreview the fire precautionsthat are available in theexisting house. Mainsoperated smoke detectionsignificantly improves firesafety in the home and theBuilding Regulationsrequire that it should beinstalled where cellars areconverted to habitablerooms.
Drainage: if you are lookingto include a sink, bathroom,shower room or even a
washing machine in yourconversion it is importantthat you consider drainage
at an early stage. Any newappliances will need toconnect to your existing fouldrainage system and thedrains are usually above thelevel of the appliances that
you wish to install. You arelikely to need to install apumped drainage systemand various packagesystems are available thatmacerate the drainage andpump it via a small diameterpipe to the existingdrainage system. Whenplanning your layouts make
sure that there are suitableroutes for pipes to run to apoint where they canconnect to existing drains.
The Ceiling: unless yourexisting cellar has anadequate ceiling you willneed to provide one as partof your conversion.
Plasterboard is the mostcommon material used forceilings as it offers good fire
resistance and flame spreadproperties. Other materialscan be used but they willgenerally need to be treatedto improve their fireperformance. If either your
cellar or the room above isto be used as a bedroomyou will need to install100mm of acoustic quiltwithin the floor voidbetween the rooms.
Heating: to maximise theusability of the room youwill probably want to install
heating, in most instancesthe most effective way ofdoing this is to extend theexisting central heatingsystem. You will need tocheck with your plumber orheating engineer to ensurethat your existing boiler andpump has sufficientcapacity to serve any
additional radiators. Anynew radiators should befitted with thermostatic
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42 South Oxfordshire & Vale of White Horse Guide to Extending Your Home
valves to control the roomtemperature. If it is notpossible to extend theexisting system, or, if youprefer an alternativemethod of heating, e.g.
electric panel heaters,careful consideration shouldbe given as to how thesecan be switched andcontrolled to ensure thatthey function efficiently.
Ventilation: any newhabitable rooms will need tobe ventilated and this can
sometimes present aproblem for cellarconversions. Where thecellar contains a light wellthis can sometimes beadapted to include anopening window equivalentto 1/20th of the floor area ofthe room with a trickle ventat high level. In any bath or
shower rooms an extract fanshould be fitted and if theydo not have openingwindows extract fans shouldbe fitted that are triggeredby the light switch withoverrun timers that allowthe fan to remain on afterthe light is turned out.Where natural ventilation
through windows is notpractical a mechanicalventilation system will needto be installed and variouspackage systems areavailable on the market.Ventilation should beconsidered early in thedesign stage as, if
mechanical ventilation isrequired, the duct work willneed to be accommodated.
Thermal Insulation: CO2emissions are a major
concern in todaysenvironment and you willneed to provide a high levelof insulation within yourconversion. Your cellarshould provide an insulatedenvelope so that theamount of heat escaping isminimised. The walls andfloor of your cellar are
generally lined withinsulating boards and thewindows should include24mm double glazing unitsincorporating low emissivityglass. As well as insulatingyour extension you willneed to consider theefficiency of any servicesyou put into it. Low energy
light fittings should be usedwhere possible and any newheating systems shouldwork to high levels ofefficiency and have suitablethermostats and controls.
Electrics: you are likely torequire some electricalalterations as part of yourconversion. Depending on
the age and condition ofyour existing electricalsystem it is sometimespossible to extend existingcircuits but sometimes newcircuits and even a newdistribution board will berequired. It is a good idea toget advice from a competent
electrician at an early stage.When appointing anelectrician please ensurethat they are able to issueyou with BS7671 testcertificates when they have
completed their installationas these will be requiredbefore your BuildingRegulations CompletionCertificate can be issuedand you will incuradditional costs if the testcertificates have notbeen provided.
Conclusion: a wellconverted cellar can be aninteresting space and canbe a great way of gettingextra room in your house.Cellar conversions are oftennot simple projects and apoorly thought-outconversion can reduce yourpropertys value and in
some cases compromiseyour safety and thestructural integrity of yourhome. It is important toensure that you plan yourconversion carefully and getthe work carried out by anexperienced contractor.
The Building Regulations
exist to ensure thatbuildings are constructed toa reasonable standard; Valeof White Horse BuildingControl will be pleased toprovide you with any furtherassistance that you requireduring the design andconstruction of your project.
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Other
AlterationsIntroduction: a number ofhome improvement projectsare covered by the BuildingRegulations and thischapter sets out to explainhow the BuildingRegulations affect some of
the projects that you maybe considering.
This guide is not asubstitute for professionaladvice but has been written
to provide you with usefulinformation about how theBuilding Regulations willaffect your project.
Removing InternalWalls
Internal walls have anumber of functions, someare fundamental to thestructure of the house,some offer fire protection to
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44 South Oxfordshire & Vale of White Horse Guide to Extending Your Home
the stairway and othersmerely divide up the spacewithin the house and can bealtered or removed withvery few issues.
Load bearing walls are
fundamental to thestructure of the house andcareful consideration needsto be given before they canbe altered or removed.Alteration or removal of loadbearing walls requiresBuilding Regulationsconsent and generallyspeaking a structural
engineer should becommissioned to design thealteration. The structuralengineer will considerwhat loads the wall is takingand will design a beam and,if necessary, othersupporting structure toensure that the loads thewall was carrying are safelytransmitted to the ground.We will then inspect thework as it progresses andthen issue a completioncertificate to show that thework complied with theBuilding Regulations.
The walls around yourstaircase offer you some
protection to allow you toescape if your housecatches fire and thealteration of these wallsrequires BuildingRegulations consent.If these walls are removedit is essential that yourhouse is fitted with mainsoperated smoke detection
and that all of your roomshave windows suitable forfire escape purposes(see Fire Precautions
Domestic Extensions).If you wish to removeone of these walls contactus and we will arrange tovisit you to establish
whether the walls areessential to the fireprotection within yourhouse and advise what,if any, additional work isrequired to allow thealterations to take place.
Bay Windows andChimneys
In Building Regulationsterms these are basicallysmall extensions.They require BuildingRegulations consent andmuch of the guidance in theExtensions chapter isrelevant albeit on asomewhat smaller scale.
Chimneys require liningwith a flue liner that issuitable for the fire thatthey will serve and the
installer should testthe flue prior tocommissioning the fire.
We will carry out a series ofinspections on theseprojects and issue acompletion certificate whenthe works are satisfactorilycompleted.
New Drainage
Replacement kitchens andbathrooms do not generallyneed Building Regulations
consent but where newdrainage is installed toserve a new bathroom orother appliance BuildingRegulations consent isrequired. With theseprojects we will carry out aseries of inspections toensure that the drainageand ventilation is
satisfactory and issue acompletion certificate whenthe works are satisfactorilycompleted.
In certain areas radon protection will be required
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South Oxfordshire & Vale of White Horse Guide to Extending Your Home 45
Replacement Boilersand Alterations toElectrical Systems
These alterations require
Building Regulations
consent although in practicemost of this work is carried
out by contractors who can
self certify their work.
Details of the self
certification scheme are
given in the introduction to
this guide and, if your
contractor is able to self
certify, you will not need to
make a separate BuildingRegulations application.
If you wish to use acontractor who is notregistered with a selfcertification scheme please
contact us and we willarrange for the necessaryapplication to be submitted,carry out the relevantinspections and issue yourcompletion certificate whenwork has been satisfactorilycompleted.
Whichever scheme you use
make sure that you get the
completion certificate asyou will need this if youwish to sell your house.
Conclusion
This guide has endeavoured
to provide usefulinformation about a rangeof typical domestic projectsand we hope that you havefound it useful.If you need any furtherinformation about a projectthat you are consideringplease contact us and wewill be happy to provide
further advice.
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Radon: Radon is a naturalradioactive gas. Youcannot see, smell, hear orfeel it. It comes fromminute amounts ofuranium that occurnaturally in all rocks and
soils and the air in allbuildings contains adegree of radon.
The gas can move throughcracks and fissures in thesubsoil and eventually tothe atmosphere. Most ofthe radon will disperseharmlessly but some willpass from the ground and
collect in spaces under orwithin buildings.
Some areas of the countrymight have unacceptablyhigh concentrations unlessprecautions are taken; thegranite areas of South-West England is one ofthese areas.
The level of radonprotection required to yourextension depends on thelocation of your property.This can be determinedeither by consulting yourlocal Vale of White HorseDistrict Council BuildingControl Services office orby accessing the maps on
the Building ResearchEstablishment website.The maps indicate thehighest radon potential
within each 1-km grid anddetermines whether full orbasic radon precautionsare required or if radonprotection is not neededat all. More accurateinformation is available
from the Health ProtectionAgency or the BritishGeological Survey.
Radon protective measurescan be included relativelyeasily and cost-effectivelywithin extensions todwellings.
All extensions to dwellings
which fall within a full orbasic radon protection areawill be required toincorporate an appropriatelevel of radon protection ifa new ground floor isprovided.
Full radon protection:The damp proof membrane(minimum 1200g) acts asthe radon barrier. It isimportant that themembrane extendsthrough the cavity and islinked with a cavity tray.A subfloor sump is alsorequired. Where theexisting house has a solidfloor the sump could be
used to reduce the levelof radon in both theextension and theexisting building.
Radon
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Basic radon protection:Only the continuous dampproof membrane is required.
The detailing in both caseswill depend on the type ofconstruction used and thepositioning of the dampproof membrane, your localsurveyor will be able to giveyou further guidance,alternatively examples areprovided on the BREwebsite.
Wherever possible theconstruction joint between
the new floor and theexisting house should besealed. Where radonbarriers have beenincorporated in both thenew floor and the existingfloor, the aim should be tojoint the two barriers wherethey meet within the wall ofthe house. This is difficultto achieve in practicewithout damaging theexisting barrier and asimpler alternative is to cuta chase in the wall slightlyabove or below the existingbarrier in which to tuck thenew barrier.
If the existing house has a
beam and block orsuspended timber floor,
care should be taken to
ensure that the provision of
sub-floor ventilation is
maintained.
It is recommended that you
have your house measured
for radon before plans areprepared. Ideally
measurement should be
over at least 3 months; the
Health Protection Agency
(HPA) can provide detectors
for this purpose. If your
dwelling is found to exceed
the current recommended
action level, appropriateprotection measures can be
incorporated into yourbuilding project.
Useful contacts
HPA Radon Studies Group,Radiation ProtectionDivision, Health Protection
Agency, Chilton, Didcot,Oxon, OX11 0RQwww.ukradon.org
Building ResearchEstablishment, Garston,Watford, WD25 9XX