Energy Efficiency Standards

June2012

LK Reynolds

Sustainability Development Executive

Government gazette – 9 September 2011

Implementation – 9 November 2011

Applicable to new plans & renovations needing plan approval

CONTENT OF THE PRESENTATION

Introduction

NBR-XA

SAN 10400-XA

Additional Requirements

SANS 204

Green Buildings

FAQ’s

Conclusion

INTRODUCTION

Energy efficiency (EE) in buildings is www (win win win)

South Africa’s energy demand – Demand > Supply Load shedding

Huge price increases

Buildings are the largest end use of energy and account for 40% of end use of energy & 23% GHG.

Most of this consumption is for heating, cooling, ventilation and hot water

South Africa signatory to Kyoto protocol

Generally not designed or constructed to maximize energy efficiency

Feasible saving potentials for EE are very large both in new and existing buildings

National Building Regulations

Under previous Standards Act – SABS was mandated to administer National Building Regulations and Building Standards Act.

NRCS Act of 2008 promulgated

National Building Regulations responsibilities transferred to National Regulator for Compulsory Specifications (NRCS)

Both SABS & NRCS report to DTi

Enforcement of NBR is responsibility of Local Government

NRCS also mandated to ensure proper implementation & execution of NBR

Aim Of NBR

To ensure safe buildings based on

Acceptable building science practice

Good workmanship

Quality materials

Not intended to be handbook on good building practice

Simple & short way to ensure that buildings will be designed & built so that persons may live & work in a healthy, safe environment

Other aspects affecting comfort & convenience are not controlled by NBR

Regulatory Framework

National Building Regulations and Building Standards Act, 1977 (Act 103 of 1977).

National building regulations are issued in terms of the above act and is a compilation of various parts (A to X:–

Part A – General Principles and RequirementsPart B – Structural Design:Part X – Environmental Sustainability

Part XA – Energy Usage in Buildings

SANS 10400 is a National Standard:The Application of the National Building Regulations (also compiled in many parts to correlate to the National Building Regulations)

National Building Regulation XA

Rationale behind NBR-XA structure

• Biggest energy user in residential buildings – Hot water supply.– Look to renewable energy or energy efficient sources– XA2

• Biggest energy driver is comfort – Heating, cooling & ventilation– Building envelope & services– XA1

Part XA – Energy Usage in New BuildingsXA1 - In order to contribute to the reduction of greenhouse gases, buildings and extensions to buildings in respect of which plans and specifications are to be drawn and submitted in terms of the Act, having A1, A2, A3, A4, C1, C2, E1, E2, E3, E4, F1, F2, F3, G1, H1, H2, H3, H4 and H5 occupancies or building classifications in accordance with Regulation A20, excluding garage and storages areas contained within such occupancies, shall be designed and constructed so that they:

a) are capable of using energy efficiently while fulfilling user needs in relation to vertical transport, if any, thermal comfort, lighting and hot water; or

b) have a building envelope and services which facilitate the efficient use of energy appropriate to its function and use, internal environment and geographical location.

Equipment and plant required for conducting the business of the occupant shall be excluded from these requirements.

XA2 - At least 50 % by volume of the annual average hot water heating requirement shall be provided by means other than electrical resistance heating including but not limited to solar heating, heat pumps, heat recovery from other systems or processes and renewable combustible fuel.

XA3 - The requirements of sub-regulation XA1 shall be deemed to be satisfied when such building is designed and constructed in accordance with the following requirements:

a) has an orientation of the longest axis, shading, services and building envelope in accordance with SANS 10400-XA; or

b) is the subject of a rational design by a competent person, which demonstrates that the energy usage of such building is equivalent to or better than that which would have been achieved by compliance with the requirements of SANS 10400-XA; or

c) has a theoretical energy usage performance determined using certified thermal calculation software, less than or equal to that of a reference building in accordance with SANS 10400-XA.

Occupancies includedClass of Occupancy Type of Occupancy

A1 Entertainment and public assembly

A2 Theatrical and indoor sport

A3 Place of instruction

A4 Worship

C1 Exhibition Hall

C2 Museum

E1 Place of detention

E2 Hospital

E3 Other institutional (residential)

E4 Medical facilities

F1 Large shop

F2 Small shop

F3 Wholesaler’s store

G1 Office

H1 Hotel

H2 Dormitory

H3 Domestic residence

H4 Detached dwelling house

H5 Hospitality

Occupancies excluded

• A5 - Outdoor Sport

• B1,B2,B3 - Commercial Service Building

• D1,D2,D3,D4 - Industrial and Plant rooms

• J1,J2,J3,J4 - All garages and storage areas are excluded.

NBR-XA

If mixed occupancy – applies to relevant segment

Where provided, max 50% by volume of hot water can be from a traditional geyser (paraphrase)

Buildings shall be designed and constructed so that they

a) are capable of using energy efficiently while fulfilling user needs in relation to vertical transport, if any, thermal comfort, lighting and hot water; or

b) have a building envelope and services which facilitate the efficient use of energy appropriate to its function and use, internal environment and geographical location.

Equipment and plant required for conducting the business of the occupant is excluded.

Hot Water Supply – XA2

Regulation: A minimum volume fraction of 50% of the annual average heating requirement for hot water shall be provided by means other than electric resistance heating or fossil fuels including, but not limited to

Solar heating

Heat pumps

Geothermal heat

Renewable combustible fuel

Heat recovery from alternative systems and processes

SANS 10400 XA Geyser systems and Pipe Insulation - requirements

All exposed hot water service pipes shall be clad with insulation with a minimum R-value in accordance with the table below.

Internal diameter of pipe Minimum R-value

<80mm 1.0

>80mm 1.5

Determined with a hot surface temperature of 60 °C and an ambient temperature of 15 °C.

Compliance to NBR-XA – XA31 Rational design

This alternative requires input of a professional “competent” person Thermal performance of building needs to be calculated Performance should be equal or better than specified in SANS

10400XA

2 “Deemed-to-Satisfy”

Compliance with requirements in SANS 10400-XA

3 Comparison with a compliant theoretical (reference) building

Energy usage of building shall be less than or equal to that of a reference building

Reference building should be designed to “Deemed to Satisfy” standards

This alternative requires input of a professional “competent” person

SANS 10400-XA

Compliance to SANS 10400-XA: Deemed-to -satisfy

Option 1: Compliance to SANS 10400XA “Recipe” for building elements Requirements partially aligned with SANS 204

Option 2: Compliance to Tables Thermal performance of building needs to be calculated Max Energy Consumption & Max Energy Demand must comply with tables in

SANS 10400-XA Thermal performance calculations software accredited by Agrement SA to be

used This alternative requires input of a professional “competent” person

Option 3: Comparison with a compliant theoretical (reference) building Building design performance – theoretical max energy consumption &

demand shall be less than or equal to that of a reference building Building should be designed to “Deemed to Satisfy” standards Thermal performance calculations software accredited by Agrement SA to be

used This alternative requires input of a professional “competent” person

SANS 10400 – XA (Option 2) Energy Usage and Building Envelope

Conceptually based on two principles:Maximum energy demand per unit area(kVA/m2)

Maximum annual energy consumption per unit area (kWh/m2.a)

Dependent on building classification and climatic region

SANS 10400 – XA Energy Usage and Building Envelope

Climatic Zones

Drg.727a

Maximum Energy Demand

1 2 3 4 5 6 7 8

Classification of occupancy of

buildingDescription of building

Maximum energy demanda

VA/m2

Climatic zone

1 2 3 4 5 6

A1 Entertainment and public assembly 85 80 90 80 80 85

A2 Theatrical and indoor sport 85 80 90 80 80 85

A3 Places of instruction 80 75 85 75 75 80

A4 Worship 80 75 85 75 75 80

F1 Large shop 90 85 95 85 85 90

G1 Offices 80 75 85 75 75 80

H1 Hotel 90 85 95 85 85 90

a The maximum demand shall be based on the sum of 12 consecutive monthly maximum demand values per area divided by 12/m2 which refers to the nett floor area.b The climatic zones are given in annex B.

Maximum Annual Consumption1 2 3 4 5 6 7 8

Classification of occupancy of

buildingDescription of building

Maximum energy consumption

kWh/(m2·a)

Climatic zonea

1 2 3 4 5 6

A1 Entertainment and public assembly 420 400 440 390 400 420

A2 Theatrical and indoor sport 420 400 440 390 400 420

A3 Places of instruction 420 400 440 390 400 420

A4 Worship 120 115 125 110 115 120

F1 Large shop 240 245 260 240 260 255

G1 Offices 200 190 210 185 190 200

H1 Hotel 650 600 585 600 620 630NOTE 1   The annual consumption per square metre shall be based on the sum of the monthly consumption of 12 consecutive months.NOTE 2   Non-electrical consumption, such as fossil fuels, shall be accounted for on a non-renewable primary energy thermal equivalence basis by converting mega joules to kilowatt hours.

a The climatic zones are given in annex B.

Building Envelope – Option 1

≈ 25% Roof

Walls≈ 30% Glazing

Thermal bridges

≈ 10% Ground

Floor

≈ 10%

≈ 10%

≈ 15% Air renewal

Summer

Winter

Principle of insulation

Improving the building envelope can reduce energy losses and shrink energy consumption by up to 90%

Building Code References

Orientation SANS 10400-XA Shading SANS 204

Walls SANS 10400-XA Fenestration SANS 10400-XA + SANS 204 Roof Assembly SANS 10400-XA Flooring SANS 10400-XA Services (excluding hot water) SANS 204

Energy Usage & Building Envelope (Option 3)- Orientation- Shading

OrientationCompact in plan with most glazing on northern side

Living spaces on northern side

Longer axis of dwelling to be east-west

Roof overhang to shield northern windows in midday summer sun

ShadingAs per SANS 204

Projection of roof overhang - ratios

Total Energy = Energy for cooling + Energy for heatingTotal min = optimal orientation 

Total Energy = Energy for cooling + Energy for heatingTotal min = optimal orientation 

Shading 

Requires a permanent feature which extends horizontally on both sides of the glazing for the same projection distance, P (see next slide for figure on shading feature)

or provides the equivalent shading with a reveal or other shading element (see figure on shading projection) or

have an external shading device which is capable of restricting at least 80% of summer solar radiation.

For glazing where G exceeds 0,5 m, the value of P (see figure on shading feature or device) shall be halved.

KeyP horizontal distance, expressed in metres, from the glass face to the shadow casting edge of any shading projectionH vertical distance from the base of the glazing element to the same shadow casting edge used to measure PG vertical distance from the head of the glazing element to the shadow casting edge of any shading projectionNOTE: An adjustable shading device that is capable of completely covering the glazing may be considered to achieve a P/H value of 2.

Shading feature or device 

Energy Usage and Building Envelope - Floors

FloorsIf in-slab or in-screed heating slab to be insulated with minimum R-value of 1

To calculate the R value you need to know (R value = )

The Thermal conductivity (K value) of the product - expanded polystyrene: 0.036

The product thickness: 40mm

R value =

= 1.111 m²K/W - compliant as a solution

Thickness in meters K value

Energy Usage and Building Envelope- Walls

Non-masonry walls shall achieve a minimum R-value of: R=2.2 for climatic zones 1&6

R=1.9 for climatic zones 2,3,4&5

Masonry walls shall achieve a minimum R-value of 0.35Double skin masonry with no cavity, plastered internally; and either plastered externally or unplastered face masonry externally

Single leaf masonry with a nominal thickness of at least 140mm plastered internally and rendered externally

Traditional Wall vs. the New SystemsCavity wall, dry liningR = 1.69

Cavity wall, insulationR = 1.00

Traditional wallR = 0.26

ETICS on steel frameR = 3.76

ETICS on single brick wall; R = 2.21

Lightweight steelframe wallR = 2.50

R-value required for Zone 1 = 2.20

Quoted R-value is subject to thickness of intervention insulation material

Energy Usage and Building Envelope –SANS 10400 – XA compliance

FenestrationBuildings with up to 15% fenestration area to nett floor area per storey are deemed to satisfy

Buildings with fenestration area to nett floor area per storey exceeding 15% shall comply with the requirements for fenestration in SANS 204

Air infiltration shall comply with SANS 613

Fenestration Tables – SANS 204

Energy Usage and Building Envelope- Roof Assemblies

1 2 3 4 5 6 7

Description

Climatic zones

1 2 3 4 5 6

Minimum required total R-value (m²∙K/W)

3,7 3,2 2,7 3,7 2,7 3,5

Direction of heat flow Up UpDown and

upUp Down Up

Roof AssembliesA roof assembly shall achieve the minimum total R-value specified in the table hereunder for the direction of heat flow.

1- Outdoor Air film (moving air)

Calculating the R-value of a roof

6-Indoor air film (still air)

5-RhinoBoard ceiling

3-Roof air space (Ventilated/unventilated)

2- Roofing Material

The following are taken into consideration when determining the R-value of a roof construction. The figures can be obtained from SANS 10400-XA.

7- Direction of Heat flow(Affects figures 1,3 & 6)

1- Outdoor Air film (moving air) = 0.03

Example - heat flow up

6-Indoor air film (still air) =0.11

5-RhinoBoard ceiling = 0.06

3-Roof air space = 0.18(unventilated)

2- Roofing Material = 0.02

For a building in Climatic Zones 1 & 4 to meet SANS 10400XA requirements, the following figures are used and the R-value of insulation is added.

7- Direction of Heat flow

Total R-value =3.77 m²K/W

135mm Aerolite Insulation = 3.38

Lighting and power 

Depending upon occupancy and activity, the minimum lighting levels shall be determined in accordance with the requirements of SANS 10114-1 and SANS 10400-O.

Designers are encouraged to use daylighting in their designs to reduce the energy used.

The energy demand (power) and energy consumption for the building shall be determined in accordance with the requirements given in SANS 204. 

Services

Air conditioning or mechanical ventilation systems (or both) installed in buildings shall comply with the relevant national legislation.

The air conditioning or mechanical ventilation system (or both) shall be designed to best practice.

Designed that in the event of failure of an air conditioning or mechanical ventilation system (or both), an alternative means of natural ventilation shall be provided.

All chilled water, hot water and refrigeration piping, conditioned air duct work and flexible ducting shall be insulated to limit heat gain or loss (or both) to not more than 5% from source to furthest point of delivery on a system.

Mechanical ventilation and air conditioning 

Additional Requirements

Additional Requirements for BCO

Competent Person (where necessary) – submit documentation to local authority as per SANS 10400-A

On PlansWhere provided – location, type & capacity of water heating installations

Where provided – details of fenestration and insulation

SANS 204?

Why 2 Energy Efficiency standards?

Does this cause confusion?

Look at International trends….

Europe: Energy Efficiency Targets for New Residential buildings - 2020

Relative Evolution of building regulations over time (year 2000 = index 100)

-20

0

20

40

60

80

100

120

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020

Denmark England/Wales France Germany

Poland Spain Finland Netherlands

DK, FR, DE: evolution of building energy consumption England/Wales: Code of Sustainable homes Poland: evolution of U values walls

How has this been achieved?

Building methodologies have changed in last 50 years

Driven mainly by speed and energy constraints

Regulation now driving changes

FACT’s

Comfort and Energy Efficiency

Fire Acoustic Cost Effective Thermal

SANS 204Energy Efficiency in Buildings

Far more comprehensive than the building regulations and SANS 10400 – XA

Requirements more stringent (except for roof/ceilings)

In the longer terms regulation to be upgraded and trend toward SANS 204

It is a voluntary standard

Basic minimum for green star rating

Both standards reduce the use of energy from electricity, gas, oil, or other fuels used in buildings.

Both standards exclude energy used in the operation of the building

Green Buildings

Green Buildings

Aspirational Buildings

Green Star Rating ToolsOffice, Retail, Multi-unit residential, Public Buildings

Water & Energy Bench-marking (in progress)

Building Interiors & Socio-Economic (starting soon)

Rating for the building/project“Design” or “As Built” rating

SANS 204 is conditional requirement

More than just energy efficient buildingsWater, waste, transport, indoor environment etc.

FAQ’s

FAQ’s

Does this apply to affordable/RDP/Government subsidized houses?

Yes – there are no exclusions on residential buildings

Does this prescribe the installation of Solar Water Heaters?

No – if not technically feasible, look to other energy efficient technologies

Not applicable if no hot water supplied

FAQ’s ctd.

Does this call for double glazing?No – unless building is extreme in design.

How do I know what the R-value is? Material Manufacturers must supply tested thermal performance values with thickness of material required.

FAQ’s ctd.

Are products green rated?No – projects get the ratings not components of the project

How do I know how “green” products are?Look at the requirements in the Green Star Rating tools & ask manufacturers to supply you with the test certificate results that demonstrate compliance.

Conclusion

Opportunities

NBR-XA only applies to new buildings and additions/renovations

Encourage to design to SANS 204

Energy costs escalating annually

Supply of energy is always at risk

Big opportunities in retrofit and re-insulation

Continue to manufacture “standard” thickness’s

Compliant buildings will increase in valueAttraction of Tenants

Tax Incentives