Low Energy Building Design

Scott MorrisonSamantha Dowling

Nicolas Levaudel Nicolas Soro

Site Location: Gap Site at Bath Street and Pitt Street

Plot: 50m x 50m

Building Area: 4000m2 maximum

Building Height: 25m maximum

Occupancy: 400 People maximum

Office Requirement:

› General Office Purpose

› 70% Open Plan and 30% Cellular

Full Disabled Access

Materials and Energy should be produced locally

Aim of the Project

Passive Standard High levels of insulation

Walls < 0.15 W/m2K

'Thermal bridge free' construction

Airtight building fabric

Maximum of 0.6 air changes per hour at 50 Pa

High performance windows with insulated frames

Glazing < 0.8 W/m2K

Space Heating/Cooling Energy

<15kWh/m2/annum

Primary Energy Demand

<120kWh/m2/annum

Final Design Run Through

- Dimensions : 28x28m

- Glazed surface oriented

South East

- Atrium in order to bring

maximum light inside

the building

- Shading in order to avoid

over illumination and

overheating

Building Plans N

Air Supplied

Air extracted

Ground Heat Exchanger

Ventilation DesignMechanical Ventilation Heat Recovery (MVHR) :

- Maximum flow rate : 32 000 m3/hour

- Air change per hour per person : from 8 to 30

l/s/person

- Fan consumption : 2W/l/s

Lighting

Ceiling Smart LED : 43W

36 fittings in the open area

2 fittings in the each cellular office

Occupancy sensors for cellular and toilets

Lighting

300 lux on the working plan

Variable intensity depending on the incoming light thanks to daylight sensors

Energy balance

January february march april may june july august september october november decemberTOTAL GAIN (kWh) 14452 20193 24863 23276 23251 20984 22374 20275 18516 22088 15194 13942TOTAL LOSS (kWh) 20666 20209 23235 20201 20394 16630 16592 16004 16053 20339 18654 20017Difference -6214 -16 1628 3075 2856 4354 5781 4271 2464 1749 -3460 -6075

Underfloor heating and cooling system

To heat => hot water, to cool => cold water

More cost effective and energy efficient than air conditioning

Electricity Demand

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Energy Demand

Total Energy Demand

Demand To Be Met By Renewables

PV Potential

Energ

y C

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kW

h)

Total annual electricity demand = 125398 kWh

50% demand to be met by renewables = 62699 kWh

Photovoltaics

Rooftop PV flat 432.6m2 11.8% efficiency = 44395kWh

Overhang PV flat 132m2 11.8% efficiency = 6433kWh (30% Shaded)

Overhang PV vertical 132m2 11.8% efficiency = 9482kWh (30% Shaded)

Rooftop PVT system flat 104.4m2 13% efficiency =11785kWh

Increased efficiency as thermal system reduces operating temperature

Total electricity generated = 72096kWh

Solar Thermal HybridHot water demand 3150litres/day

PVT thermal efficiency = 0.7

Absorption 85% as PV rather than glass

100 litres per panel

45 panels required

Panel area 2.32m2

Total system size 104.4m2

http://www.goodenergy.co.uk/generate/choosing-your-technology/home-generation/solar-thermal/solar-thermal-faqs

Additional hot water heating required

during winter months

1071.9kWh

0.29kWh/m2/a

Electrical emersion heater

Building Energy PerformanceWalls Ground Floor

SlabRoof Glazing

Materials

• LCC GGBS Insitu

Concrete Frame

• British

Gypsum®

Plaster

• Low

Conductivity

Teplo4™ Wall

Ties

• SVP Insulation

• ECO Smart™

Sandstone

Cladding

• LCC GGBS Insitu

Concrete Slab

• Kingspan®

Thermafloor™

TF70 Insulation

• Damp Proof

Membrane

(Waterproofing)

• LCC GGBS

Insitu Concrete

Slab

• Kingspan®

Thermaroof™

TR26 LPC/FM

Insulation

• Damp Proof

Membrane

(Waterproofing)

• Gypsum Plaster

Atrium:

• A98 Atrium

Glazing Units

Office:

• Low

Emissivity

Triple

Glazing

• Fully

Insulated

Frame

Passive Standard

0.15 0.15 0.15 0.80

U-Value Achieved (W/m2K)

0.13 0.14 0.112 0.79

Building Energy Performance

Typical Practice Best Practice Passive Standard Our Office

Overall Energy (kWh/m2/annum) 226 178 120 48.94

Cooling & Heating (kWh/m2/annum) 209 111 15 11.87

Lighting (kWh/m2/annum) 54 27 - 5.27

Office Equipment (kWh/m2/annum) 31 23 - 8.95

ComparisonOur Office Energon Passive

Office

Overall Energy 41 44.43

Cooling & Heating 12.16 12.3

U-Value (W/m2K)

Ground Floor Slab

Roof

Glass Roof Atrium

Typical Office Windows

Wall Construction

0.22

0.12

1.80

0.84

0.11 GF, 0.13 Office

0.14

0.112

0.79

0.79

0.13

Design AlterationsSize increased from 25m x 25m to 28m x 28m

-increase atrium size and allow more natural light to enter Pitch of roof – changed from angled to flat

pitch was not feasible by exceeding the maximum height not enough light entering the atrium

Overhangs designed to create shading Solar gains and low u-values of materials creating internal overheating

PV installed on to overhangs Electrical demand exceeded 50% onsite generated requirement

Change Ventilation Flow RateCooling was not sufficient so ac/h increased

Sustainable

What we have learned

• Apply what was learned in the first semester

• How to use new software (i.e. Dialux, Dreamweaver, etc)

• How to present our ideas

• Work as a team

Website• All details available on the website:

Project detailed per section Presentations and calculations downloadable Pictures …

Sample Wall Construction

Solar GainArea of Glazing = 660m2

Transmittance = 0.57South facing vertical

Total Solar Heat Gain = 216110kWh

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Solar Control

Green Building Store http://www.greenbuildingstore.co.uk/page--ecoplus-

energy-efficient-glazing.html

External shading overhangs/louvres

Light shelf

Thanks for Listening Any Questions?