module 3 - understanding energy efficiency

National Construction CodeTraining Program

MODULE THREE

Understanding Energy Efficiency Provisions for Class 1 and 10 Buildings

Introduction to Module Three

• This training module is one of a series produced by the Australian Building Codes Board; the organisation responsible for the development and maintenance of the National Construction Code (NCC)

• For the purposes of this presentation it is assumed that participants have a general understanding of the content of ABCB training Modules One and Two

Scope of the BCA Methods of ComplianceIntroduction to Module Three

National Construction Code Series

Scope of the BCAIntroduction to Module Three Methods of Compliance

Building Code

Volume ThreeGuide to

Volume OneVolume OneAppendices

Volume TwoVolume One

PlumbingCode

Recap on Module One

• Module One was titled: An Introduction to the Building Code of Australia – Volume One and Two of the NCC Series

• The objective of Module One was to provide information on:

− the background to the development of the BCA

− the operation of the BCA, and

− the application of the BCA


The Building Code of Australia

• The BCA establishes minimum standards for new building work• The BCA:

− Is referenced in State/Territory law – see next slide

− Is amended annually

− Requirements are intended to be cost effective

− Requirements are intended to eliminate poor practice

− Does not address best practice


Scope of the BCA Methods of Compliance

STATE & TERRITORY BUILDING ACTS

STATE & TERRITORY BUILDING REGULATIONS

TECHNICAL STANDARDS

ADMINISTRATIVE MATTERS• Approvals• Appeals• Registrations• Refurbishments• Building standard


Presentation of the BCA

• The BCA is presented in two Volumes• This is to correlate with the historic operation of the building

industry

• In general, industry tends to work in either the housing sector or the commercial sector, although some large companies work in both sectors

• The BCA endeavours to follow this division


BCA Volumes One and Two

• Volume One contains requirements for the design and construction of commercial buildings; i.e. Class 2 to 9 buildings, plus some Class 10 structures

• Volume Two contains requirements for the design and construction of domestic buildings; i.e. Class 1 and 10 buildings, plus some Class 10 structures


Recap on Module Two

• Module Two was titled: Understanding the BCA’s Performance Requirements

• The objective of Module Two was to provide information on how to comply with the BCA without using Deemed-to-Satisfy Provisions – i.e. by developing an Alternative Solution which complies with the relevant Performance Requirements.


The Building Code of Australia

Volume Two is divided in three sections –• Section 1 – General Provisions which presents the general structure

and operation of the BCA.• Section 2 – Performance Provisions which presents the mandatory

technical requirements of the BCA.• Section 3 – Acceptable Construction which presents optional means

of compliance to the Performance Requirements. These are expressed as Deemed-to-Satisfy Provisions.



1.2.2

Objective of Module Three

• The objective of Module Three is to provide fundamental information on BCA energy efficiency provisions relating to Class 1 buildings, as well as Class 10 buildings that have a conditioned space

• The information provided in this presentation relates to the national content of the BCA and does not address State or Territory variations


BCA Energy Efficiency

BCA requirements reduce greenhouse gas emissions from electricity, gas, oil, or other fuels used in buildings for:

• Heating

• Cooling

• Ventilation

• Artificial lighting

• Hot water (space heating and sanitary)• Other domestic services


BCA Requirements

• The BCA only addresses energy used by a building's services to operate

• Does not include energy used in manufacturing building materials or construction of a building (i.e. embodied energy)

• Does not include portable appliances within a building such as computers or fridges


Background

Scope of the BCA

Methods of Compliance

Module Three


Content of Module Three

• Principles of Energy Efficiency• General Scope of BCA provisions• Performance Requirements• Deemed-to-Satisfy Provisions• Alternative Solutions• Verification Methods• Administrative Matters


Background toEnergy Efficiency Provisions

General Background

• Over the past decade international awareness of greenhouse gas (GHG) emissions and their influence on global warming has grown significantly

• GHG is a natural part of the Earth’s atmosphere that capture the Sun’s warmth and keep Earth’s surface temperature at a life supporting level


General Background

• Increased concentrations of GHG will cause variations to our climate that will differ between geographic regions

• Changes may occur to temperatures, rainfall, wind speed, vegetation and animal life

• GHG emissions are increasing due to human activities such as land clearing and burning fossil fuel (e.g. coal and oil)


• 1997 – the Prime Minister issued a statement on Australia’s response to global warming that included measures to reduce energy consumption in buildings

• The building sector was not the largest contributor to national GHG emissions - although it contributed 27% of energy related GHG emissions and was the fastest growing source

• Late 1990’s - governments considered the need for new buildings to operate in an energy efficient manner


National Background


• It was apparent that market forces had not addressed the issue effectively so there was a need for regulatory reform

• Industry generally supported the need to eliminate worst practice in building design

• 2000 – Agreement by the Council of Australian Governments (COAG) to introduce energy efficiency regulations for domestic and commercial buildings


National Background


National Background

• 2001 – In response, the Australian Greenhouse Office (AGO) and the ABCB entered into an agreement to develop energy efficiency provisions and introduce these through the BCA

• 2001- 2002 - Housing energy efficiency provisions developed• January 2003 - BCA Volume Two introduced 4 star energy efficiency

provisions in climate zones 4 to 8 and 3.5 star in climate zones 1 to 3 for housing and associated buildings

• Some States/Territories had existing provisions in place and did not adopt new BCA requirements


• BCA 2005

− Introduced similar star requirements for Class 2 and 3 buildings and Class 4 parts of a building as for housing, i.e. SOU’s must achieve a minimum of 3 stars, but achieve a 4 star average in climate zones 4 to 8 and 3.5 star average in climate zones 1 to 3.

• BCA 2006

− Introduced requirements for Class 5 to 9 buildings

− Enhanced requirements for Class 1 and nominated Class 10a buildings from 3.5 / 4 star to 5 star


National Background


• BCA 2010

− Enhanced the requirements for Class 5 to 9 buildings

− Further enhanced the requirements for Class 1 and nominated Class 10a buildings from 5 star to 6 star

− Also enhanced requirements for Class 2 buildings and Class 4 parts of a building (average 6 star, minimum 5 star)


National Background


What is a House Star Rating?

• A house star rating is a quantified benchmark used to describe the energy efficiency performance of a building’s shell based on an annual energy load

• The rating is used in the BCA and is derived using computer software packages; AccuRate, BERS Pro and FirstRate 5


Draft Provisions

• Originally developed through stakeholder committees, specialist working groups and specialist consultants

• Proposals were refined through industry and community consultation

• Latest provisions were subjected to a formal Regulation Document process and Regulation Impact Statement process


Regulation Impact Statement

• Under an IGA, the ABCB must only propose new regulation as a final option

• All proposals for change to the BCA must be subjected to a rigorous regulatory impact assessment process that includes cost benefit analysis

• The new regulation must generate the greatest net benefit for the community


Four Stage Process


• Using a four stage process, the ABCB has now introduced energy efficiency requirements for all classes of buildings− 2003 - Class 1 & 10 (4 star / 3.5 star)− 2005 - Class 2 to 4 (4 star / 3.5 star average – 3 star

minimum)− 2006 - Class 5 to 9; plus

- Class 1 & 10 enhanced (Verification 5 star)− 2010 - Class 3 and 5 to 9 enhanced; and

- Class 2 and 4 (6 star average – 5 star minimum)- Class 1 & 10 (6 star)


Voluntary Best Practice

• The Department of Climate Change and Energy Efficiency (DCCEE) has also developed a series of other programs - aimed at assisting designers to go beyond the minimum requirements of the BCA

• These programs promote best practice rather than BCA minimum requirements

• Information can be found at: www.climatechange.gov.au


http://www.climatechange.gov.au/

Principles of Energy Efficiency

Objective of BCA Provisions

• The objective of the BCA energy efficiency provisions is to reduce GHG emissions by reducing operational energy use of new buildings without reducing comfort and amenity

• BCA requirements primarily address:

− heat flow - into and out of a building through the building envelope, and

− domestic services - that use energy e.g. air-conditioning and hot water


Definition of Envelope

Envelope, for the purposes of Part 2.6 and Part 3.12, means the parts of a building’s fabric that separate artificially heated or cooled spaces from –

(a) the exterior of the building; or

(b) other spaces that are not artificially heated or cooled


Definition of Domestic Services

Domestic services means the basic engineering systems of a house that use energy or control the use of energy; and

(a) includes heating, air-conditioning, mechanical ventilation, artificial lighting and hot water systems; but

(b) excludes cooking facilities and portable appliances.


Principles of Energy Efficiency

• The efficient performance of the building envelope plus the building's domestic services results in reduced:

− demand for a service, especially in a moderate climate zone,

− size of a service,

− operating time of a service, and

− energy consumption of the service• The use of fuels with the lowest practical greenhouse gas intensity


Application of Requirements

• Not all of Australia has the same climate so the BCA elemental Deemed-to-Satisfy Provisions vary across eight (8) climate zones

• Climate zone 1 is hot and humid while climate zone 8 is cold

• A map of the location of climate zones is provided at Figure 1.1.4 – see next slide


Climate Zone MapFigure 1.1.4


Individual State and Territory maps are available on the ABCB website at:

www.abcb.gov.au


Climate Zone Map


http://www.abcb.gov.au/

Application of Requirements

• The primary intent of the BCA provisions is to reduce energy usage for cooling services in warmer climate zones and heating services in cooler climate zones

• The extent of specific requirements vary with climate zone and sometimes with the use of the building


Achieving Energy Efficiency

• Insulating and/or shading the building fabric

• Controlling energy flow through glazing

• Reducing air leakage via building fabric

• Creating internal air movement for cooling• Improving the efficiency of heating, cooling, lighting, hot water

systems and pools


General Scope of BCA Provisions

Sections of Volume Two

• The application of the BCA provisions is governed by the content of Sections 1 and 2 of Volume Two

• Section 1 – General Provisions – presents the "general rules" by which the BCA provisions are applied

• Section 2 – Performance Requirements – presents the mandatory requirements of the BCA and the Verification Methods


Sections of Volume Two

• Section 3 of Volume Two presents the Deemed-to-Satisfy Provisions

• These provisions are presented as either an:

− Acceptable Construction Manual or

− Acceptable Construction Practice

• The principal benefit of using Deemed-to-Satisfy Provisions is that they are accepted as meeting the mandatory Performance Requirements

Scope of the BCAIntroduction to Module Three Methods of Compliance

Energy EfficiencyPerformance Requirements

Part 2.6 of Volume Two

Energy Efficiency Requirements

• There are two mandatory Performance Requirements for energy efficiency i.e.

− P2.6.1 for the thermal performance of a building’s fabric

− P2.6.2 for the domestic services’ –

– energy efficiency

– energy source


P2.6.1 Building


P2.6.2 Services


Domestic Services

• Domestic services means the basic engineering systems of a house that use energy or control the use of energy; and

(a) includes heating, air-conditioning, mechanical ventilation, artificial lighting and hot water systems; but

(b) excludes cooking facilities and portable appliances


Energy EfficiencyDeemed-to-Satisfy Provisions

Part 3.12

• Part 3.12 presents the optional Deemed-to-Satisfy Provisions that may be used to achieve compliance with the mandatory energy efficiency Performance Requirements

• Part 3.12.0 provides two optional pathways to achieve compliance, which are –

− Using a house energy rating solution, including some elemental Deemed-to-Satisfy Provisions; or

− Using the elemental Deemed-to-Satisfy Provisions alone.


Part 3.12

Option 1

Energy Rating Solution• Energy rating at 3.12.1.0• Specific 3.12.1 provisions• 3.12.3 for Sealing


Option 2

Elemental Solution• 3.12.1 for Building Fabric• 3.12.2 for Glazing• 3.12.3 for Building Sealing• 3.12.4 for Air Movement

3.12.5 for Services


• The elemental option Deemed-to-Satisfy Provisions address the following parts of a building:

− 3.12.1 Building Fabric

− 3.12.2 External Glazing

− 3.12.3 Building Sealing

− 3.12.4 Air Movement

− 3.12.5 Services


Part 3.12


PART 3.12.1BUILDING FABRIC


Part 3.12.1 - Building Fabric

• Provisions for building fabric address:

− Thermal insulation

− Roofs

− Roof lights

− External walls

− Floors

− Attached Class 10a buildings


Part 3.12.1 - Building Fabric

• The intent of these provisions is to ensure the building envelope is an effective means of resisting unwanted heat flow

• Heat flow may be either predominantly into or out of a building depending on the climate zone

• A thermally efficient building envelope means less energy is needed to artificially heat or cool internal spaces


Example of Envelope Performance

Proportion of envelope heat gain

floor0%

walls8%

roof5%

doors0.4%

glazing87%

Proportion of envelope heat loss

floor18%

walls14%

doors1%

roof18%

glazing49%


Some Relevant Terms

• R-Value – means the thermal resistance of a component calculated by dividing its thickness by its thermal conductivity

• Total R-Value – means the sum of the R-Values of components in a composite element – it can be determined by calculation or reference



Some Relevant Terms

• R-Value of an uninsulated clay masonry veneer wall


Some Relevant Terms

• Total U-Value – means the thermal transmittance of a composite element, i.e. the ability of an element to conduct heat


THERMAL INSULATION


Thermal Insulation

Thermal insulation must –• Comply with AS/NZS 4859.1 • Be installed to form a consistent and continuous barrier, other

than at studs etc, in accordance with the BCA’s and manufacturer’s requirements

• Not interfere with the operation of a domestic services or fitting, such as downlights


Thermal Insulation

Thermal insulation may be –• Added to elements of the building fabric to achieve the required level

of thermal performance• Either reflective insulation or bulk insulation


Thermal Insulation

Thermal insulation needs to be installed so that –• Any required airspace is provided adjacent to the reflective surface

of reflective insulation

• The thickness of bulk insulation is maintained as compression of insulation material can reduce the R-Value

• Note: Consideration needs to be given to the risk that artificial cooling or heating of internal spaces may promote condensation within adjoining elements.


ROOFS


Roofs

• The roof of a house is typically the largest element of external fabric exposed to solar radiation

• Roofs and/or ceilings need to be insulated to achieve the required level of thermal performance

• Insulation performance required will depend upon direction of heat flow, i.e. downwards or upwards


Direction of Heat Flow

• The direction of heat flow that needs to be counteracted will depend on the climate zone

• The direction of heat flow is the dominant direction during typical hours of occupation of the building


Roofs

Roof assemblies must achieve the Total R-Value specified in Table 3.12.1.1a for the direction of heat flow

For a pitched roof with flat ceiling:

− at least 50% of the roof insulation on the ceiling


Table 3.12.1.1a


Solar Absorptance Values

• Low solar absorptance values are associated with light coloured roof materials, such as white or cream

• Light coloured roofs reduce the flow of heat from radiation better than dark coloured roofs so don’t require as high a Total R-Value.


Solar Absorptance Values

Colour Value

Slate (dark grey) 0.90

Red, green 0.75

Yellow, buff 0.60

Zinc aluminium — dull 0.55

Galvanised steel — dull 0.55

Light grey 0.45

Off white 0.35

Light cream 0.30


Total R-Value

• In climate zones 1 to 5 - the Total R-Value may be reduced if the roof space is ventilated

• When the area of required insulation is reduced, as a result of downlights, flues or exhaust fans, the loss of insulation must be compensated for by increasing the R-Value of insulation in the remainder of the ceiling – See Table 3.12.1.1b

• Certain roofs with metal framing and cladding require a thermal break to be installed



Total R-Value


Typical Construction

• Figure 3.12.1.1 presents Total R-Values (without insulation) for different forms of roof and ceiling construction with and without a ventilated ceiling and with “up” and “down” heat flow direction


Typical Construction

Figure 3.12.1.1 TOTAL R-VALUE FOR TYPICAL ROOF AND CEILING CONSTRUCTION

Roof construction detail Total R-Value

Ventilated

Up 0.74

Down 0.23

Unventilated

Up 0.56

Down 0.41

(c) Pitched roof with flat ceiling – Tiled roof


ROOF LIGHTS


Roof Lights

• A roof light is a skylight, window or the like installed in a roof—

(a) to permit natural light to enter the room below; and

(b) at an angle between 0 and 70 degrees measured from the horizontal plane

• BCA treats a roof light as an opening in a roof that allows heat flow in or out – so it must be protected


Roof Lights

• The total area of roof lights serving habitable rooms and connected spaces such as corridors is restricted

• Plus the aggregate area of roof lights serving a storey must be no more than 3% of floor area

• Table 3.12.1.2 specifies allowable thermal performance for roof lights


• Table 3.12.1.2 sets maximum SHGC and Total U-Values for roof lights, which vary with:

− the roof light shaft index, and

− total area of roof lights as a % of floor area of the room or space served

• Roof light shaft index is derived from the relationship of shaft length to the average internal opening

• Special requirements apply where the roof light is the only means of providing required natural light


Roof Lights


Roof claddingRoof lightshaft

Wall

Shaft length measurement:Measured from centre of the shaft at the roof to the centre of the shaft at the ceiling level.

1/2

1/2 1/2

1/2

Ceiling level

Roof lightSTEP ONE: MEASURE SHAFT LENGTH(Section view)

STEP TWO: MEASURE AVERAGE INTERNAL SHAFT OPENING AT CEILING LEVEL, OR THE DIAMETER FOR A CIRCULAR SHAFT (Plan view)

Roof lightshaft

X

Y

Average internal opening = (X + Y) / 2

STEP THREE: DIVIDE THE CENTRE SHAFT LENGTH (STEP ONE) BY THE AVERAGE INTERNAL SHAFT OPENING (STEP TWO)

Roof light shaft index = Roof light shaft length / Average internal opening at ceiling level

EXTERNAL WALLS


External Walls

• As with roofs, the construction of external walls is a major factor in the thermal efficiency of a building

• External walls don’t necessarily need to achieve a minimum Total R-Value to comply

• Less insulation is required for high mass walls• Table 3.12.1.3a (low mass walls) and 3.12.1.3b (high mass walls)

present options for wall construction within each climate zone


External Walls

Typical Types of Wall Construction


(a) Weatherboard (b) Fibre cement sheet

Total R-Value 0.48 Total R-Value 0.42


External Walls

• If the wall construction cannot comply – glazing in the same storey might be allowed to compensate

• Metal framed walls with light weight external cladding require a thermal break

• A significant amount of Explanatory Information is provided in BCA Volume Two


FLOORS


Floors

• There are separate requirements for:

− Suspended floors - timber or concrete

− Suspended floors with a built-in heating or cooling system

− Slab-on-ground with a built-in heating or cooling system• Suspended floors in climate zones 1-3 inclusive must achieve a Total

R-Value for heat flow in the upwards direction.• In climate zones 4-8, the Total R-Value is for heat flow downwards


Suspended Floors

• Table 3.12.1.4 (next slide) sets minimum Total R-Values for suspended floors

• Table 3.12.1.4 does not differentiate between enclosed and unenclosed suspended floors

• The effects of enclosure are included when calculating the Total R-Value of the floor construction


Table 3.12.1.4 SUSPENDED FLOOR – MINIMUM TOTAL R-VALUE

Climate zone 1 2 3 4 5 6 7 8

Direction of heat flow

Upwards Downwards

Minimum Total R-Value

1.5 1.0 1.5 2.25 1.0 2.25 2.75 3.25


Suspended Floors


• Table 3.12.1.5 – presents typical Total R-Values for suspended floors

• Table 3.12.1.5 has separate parts for suspended timber floors and suspended concrete floors

• Total R-Values are shown for four types of subfloor enclosure

Suspended Floors


Suspended FloorsExtract of Table 3.12.1.5 –


ATTACHED CLASS 10a BUILDINGS


Attached Class 10a Buildings

• A Class 10a building may include a garage, pool enclosure, etc.• A Class 10a should not compromise the thermal performance of the

Class 1 building

• Design options are described on the next slide


• A Class 10a attached to a Class 1 must either-

(a) have external fabric that achieves required level of performance for the Class 1, OR

(b) be separated by construction that achieves required level of performance for the Class 1, OR

(c) in climate zone 5 only – see over




Climate zone 5 only

• be enclosed with masonry walls - other than for doors and glazing; AND

• be separated from the Class 1 building - by a masonry wall extending to a ceiling or roof; AND

• achieve a Total R-Value in the roof - equal to that required for the Class 1 building; AND

• achieve the required garage door orientation or the glazing of the Class 1 complies using a reduced SHGC allowance.




Class10a

Class 1

Attached Class 10a Building


Class10a

Class 1

Class 1Class 10a

Class 1Class 1

Class 10a Class 1

Option (a)

Option (c)(i) Option (c)(ii)

Option (b)

PART 3.12.2EXTERNAL GLAZING


Part 3.12.2 - External Glazing

• Good design of glazing in external walls can provide the greatest gains in energy efficiency in housing

• The intent is to control the amount of energy entering or leaving a building

• The provisions address both external glazing and shading of glazing


Definition of Glazing

• Glazing - for the purposes of Part 2.6 and Part 3.12 means:

"a transparent or translucent element and its supporting frame located in the external fabric of the building, and includes a window other than a roof light”


• Location of the building (climate zone)• Total area of glazing

• Degree of exposure to the sun – orientation and shading• Type of frame and glass used• The likelihood of the building being air-conditioned


Factors Affecting Heat Transfer


Some Relevant Terms

• Solar Heat Gain Coefficient (SHGC) – a measure of the proportion of solar energy (or radiation) that passes through glazing

• High SHGC values - allow more solar energy into a room


• Total U-Value - a measure of the ability of a material to conduct heat

• Low Total U-Value means the material is a poor conductor of heat - this is good


Some Relevant Terms


• Glazing provisions require:

− calculation of allowed heat flows through glazing; and

− calculation of actual heat flows through glazing

• For Deemed-to-Satisfy designs actual heat flows must not exceed the allowed heat flows

• Part 3.12.2.1. provides formulae for calculations OR

• You can use the ABCB Glazing Calculator


Acceptable Construction Practice



• Part 3.12.2.1 – A two step process

• Step 1

• Use Table 3.12.2.1 to calculate the allowances for:

− conductance

− solar heat gain

for the glazing in each storey of the building



Acceptable Construction PracticeTable 3.12.2.1 CONSTANTS FOR CONDUCTANCE AND SOLAR HEAT GAIN

Floor construction Air movement (refer notes)

Constant Climate zone

1 2 3 4 5 6 7 8

Floor in direct contact with the ground

StandardCU 1.650 18.387 14.641 7.929 13.464 6.418 5.486 3.987

CSHGC 0.063 0.074 0.062 0.097 0.122 0.153 0.189 0.234

HighCU 1.650 18.387 14.641 7.929 13.464 6.418 5.486 3.987

CSHGC 0.069 0.081 0.068 0.107 0.134 0.168 0.208 0.257

Suspended floor

StandardCU 1.485 16.548 13.177 7.136 12.118 5.776 4.937 3.588

CSHGC 0.057 0.067 0.056 0.087 0.110 0.138 0.170 0.211

HighCU 1.485 16.548 13.177 7.136 12.118 5.776 4.937 3.588

CSHGC 0.063 0.074 0.062 0.096 0.121 0.152 0.187 0.232


• Step 2

Calculate actual:

− Aggregate conductance

− Aggregate solar heat gain

of the glazing in each storey• Each glazing element must be assessed individually and added

to establish the aggregate value for each storey




Step 2 – Aggregate Conductance

• In climate zone 1 only, calculate the aggregate conductance by multiplying the:

− Area for each glazing element

− Total U-Value for each glazing element• Add the results for each glazing element to find aggregate• In climate zones 2 to 8, the calculation is more complex with the Ew

(winter exposure factor – see Table 3.12.2.2a) and the SHGC of each glazing element considered to balance potential solar heat gains and heat loss by conduction in these climate zones.


Step 2 – Aggregate Solar Heat Gain

• Calculate aggregate solar heat gain by multiplying:

− Area for each glazing element

− SHGC for each glazing element

− Es (summer solar exposure factor) for each glazing element

• Add the results for each glazing element to get an aggregate value


• Es (summer solar exposure factor) can be found using Table 3.12.2.2b (for each climate zone)

• To use the Table you will need to determine-

− the orientation of each glazing element using Figure 3.12.2.1 – discussed later

− the P/H ratio of shading projections – using Figure 3.12.2.2 and Part 3.12.2.2 – discussed later


Step 2 – Aggregate Solar Heat gain


Step 2 – Notes

• Total U-Values and SHGCs might be included on glazing element labels or can be obtained from manufacturers

• Total U-Values and SHGCs must be for the glass and the frame combined

• Total U-Values and SHGCs must be Australian Fenestration Rating Council (AFRC) ratings


Orientation

• North orientation minimises summer sun and maximises winter sun• A glazing element is considered to face North if it faces any direction

in the North orientation sector of Figure 3.12.2.1 • The orientation of other glazing elements is determined in a similar

way


Figure 3.12.2.1 Orientation Sector


Shading

• Shading required in order to comply with Part 3.12.2.1 must comply with Part 3.12.2.2

• Shading can be provided by-

− external permanent projections such as a verandah or carport; or

− external shading devices such as shutters, blinds or screens• External shading devices must be capable of restricting at least

80% of the summer solar radiation, and if adjustable, able to be controlled by the building occupants.


Figure 3.12.2.2

Measuring P and H

Notes:

1. An external shading device that complies with 3.12.2.2(b) is considered to achieve a P/H value of 2.00.

2. Where G exceeds 500mm, the value of P must be halved.


Compare the Results

• Once aggregate conductance and aggregate solar heat gain values are calculated - compare the actual values against the allowances for each storey

• Aggregate values must not be greater than the allowances in both cases for Deemed-to-Satisfy designs


PART 3.12.3BUILDING SEALING


Part 3.12.3 - Building Sealing

• Provisions for Building Sealing address:

− Chimneys and flues

− Roof lights

− External windows and doors

− Exhaust fans

− Construction of roofs, walls and floors

− Evaporative coolers


• Limiting unwanted air leakage into and out of a building can have a major impact on stabilising temperature inside a building

• Sealing openings, joints and gaps is also an effective means of controlling drafts which can make occupants feel the temperature is lower than it actually is




• Sealing provisions generally apply to Class 1 buildings and Class 10a buildings with a conditioned space; other than:

− Where the only means of air-conditioning is an evaporative cooler in climate zones 1, 2, 3 and 5

− Permanent ventilation openings for safe operation of gas appliances

− Class 10a building accommodating vehicles




Chimneys & Flues

• Chimneys or flues of solid fuel burning appliances (e.g. timber, coal etc) must have a damper or flap that can be closed to seal the chimney or flue

• The general provisions of Part 3.7.3 "Heating Appliances" should also be considered


Roof Lights


• Roof lights serving a conditioned space or a habitable room in climate zones 4, 5, 6, 7 and 8 must be–

− sealed or capable of being sealed; and

− have an imperforate ceiling diffuser; or

− a weatherproof seal; or

− an occupant operated shutter system


External Windows and Doors

• Must be fitted with edge seals if in:

− a conditioned space; or

− a habitable room in climate zones 4, 5, 6, 7 and 8• The bottom edge of an external swing door must be fitted with a draft

protection device• Other required edge seals for doors and windows may be

compressible or fibrous strips• Compliance with AS 2047 is acceptable for windows


Exhaust Fans

• Must be fitted with a sealing device if in-


− a habitable room in climate zones 4, 5, 6, 7 and 8• A sealing device includes-

− a self-closing damper; or

− a filter – such as in a kitchen range hood


Roofs, External Walls and External Floors

• Must be constructed to minimise air leakage if part of the external fabric of –


− a habitable room in climate zones 4, 5, 6, 7 and 8• Construction must incorporate internal lining systems sealed by

skirting, architraves, cornices, caulking or the like


Evaporative Coolers

• Must be fitted with a self-closing damper or similar when serving-

− a heated space; or

− a habitable room in climate zones 4, 5, 6, 7 and 8


PART 3.12.4AIR MOVEMENT


Part 3.12.4 - Air Movement

• Provisions for Air Movement address:

− Ventilation openings location and size

− Breeze paths between ventilation openings

− Ceiling fans and evaporative coolers


• The intent of these provisions is to:

− Maximise the cooling effects of natural air movement

− Facilitate internal cross-flow ventilation

− Reduce demand for air-conditioning




• Provisions apply to habitable rooms in Class 1 buildings in climate zones 1 to 5

• Provisions are separate to Part 3.8.5

• Table 3.12.4.1 sets minimum total ventilation opening area as a % of the floor area of the habitable room based on:

− Climate zone

− Provision of a ceiling fan or an evaporative cooler




Table 3.12.4.1


Climate zones

Minimum total ventilation opening area as a percentage of the floor area for each habitable room

Without a ceiling fan or evaporative

cooler

With a ceiling fan With an evaporative cooler

1 10% 7.5% 10% (see Note)

2 10% 7.5% 10% (see Note)

3 10% 7.5% 7.5%

4 10% 5% 5%

5 7.5% 5% 7.5% (see Note)

6, 7 and 8 As required by Part 3.8.5


• Table 3.12.4.1 does not apply to Class 1 buildings in REGION D – Severe Tropical Cyclone areas – subject to specific circumstances

• Air movement may be provided from openings in certain adjoining rooms, including an enclosed verandah




Ventilation Openings


LIVING

DINING KITCHEN L’DRY

W.C.

BATH

BED 3

BED 1BED 2

Ceiling Fans & Evaporative Coolers• Ceiling fans & evaporative coolers used to establish the size of

ventilation openings under Table 3.12.4.1 must-

− be permanently installed and

− have a speed controller and

− for ceiling fans, have- 900mm minimum diameter for up to 15 m2 coverage 1200mm minimum diameter for up to 25 m2 coverage


PART 3.12.5SERVICES


Part 3.12.5 - Services

• Provisions for domestic services address:

− Acceptable construction manuals for hot water

− Acceptable construction practice for: Insulation of services Hot water supply Central heating water piping Heating and pumping

for pools Heating and cooling ductwork or spas Electric resistance space heating Artificial lighting


Services

• The intent is to minimise energy lost through operation of systems for:

− Air-conditioning

− Central heating

− Hot water supply

− Lighting

− Pool & spa heating and pumping

• The Deemed-to-Satisfy Provisions apply to domestic services in both Class 1 and Class 10a buildings and Class 10b swimming pools.


Acceptable Construction Manual

• Two manuals are referenced• Compliance with Section 8 of AS/NZS 3500.4 OR Clause 3.38 of

AS/NZS 3500.5 is deemed to satisfy P2.6.2 in regard to design and installation of a hot water supply system

• Solar hot water systems in climate zones 1, 2 or 3 are not required to comply


Insulation of Services

• Thermal insulation for piping and ductwork must-

− comply with AS/NZS 4859.1

− be protected against detrimental effects of weather and sunlight; and

− withstand temperatures to which they will be exposed


Central Heating Water Piping

• Piping not located in the conditioned space served must be insulated to achieve a minimum material R-Value specified in Table 3.12.5.1

• Material R-Value depends on-

− the exposure of the piping to the outdoors; and

− the climate zone


Heating and Cooling Ductwork

• Heating and cooling ductwork located outside the insulated building envelope must -

− achieve the material R-Value in Table 3.12.5.2

− be sealed against air loss

• Duct insulation must –

− form a continuous and consistent barrier

− be protected from damp in certain locations


Heating and Cooling Ductwork

• Table 3.12.5.2 material R-Values depend on –

− the climate zone

− the type of heating and/or cooling system• Required material R-Values are higher for ductwork than for fittings


Electric Space Heating

• An electric resistance space heating system that serves more than one room must have -

− separate isolating switches for each room; and

− separate temperature/time controls for each zone; and

− power loads of not more than – 110 W/m2 for living areas; and 150 W/m2 for bathrooms


Artificial Lighting

• Artificial lighting must not exceed specified power allowances

• The power allowance can be increased if there are sophisticated lighting controls

• Halogens must be separately switched from fluorescents• Outside lighting must be controlled by a motion sensor or be of high

efficacy


Artificial Lighting


Supply Water Heaters

Supply water heaters in a hot water supply system must be -• solar (efficiency depending upon size)• heat pump (efficiency depending upon size)• gas (5 star)• electric resistance only for small units with other conditions

applying


Pool & Spa Heating & Pumping

Swimming pools –• heating by solar only – no electric resistance boosting• if less than 680L, must have a time switch for the pump

Spas (sharing a water recirculation system with a swimming pool) –• heating by solar, gas, heat pump or a combination • if any of the heating is by gas or heat pump, the spa must have-

− a cover; and

− push button and time switch control of the heater


ALTERNATIVE SOLUTIONS

Option to Develop an Alternative Solution• To comply with BCA Performance Requirements some practitioners

will follow the Deemed-to-Satisfy Provisions just described• However – it’s often preferable to design something different from

Deemed-to-Satisfy Provisions and to develop an Alternative Solution


Remember theBCA Structure?

Developing Alternative Solutions


1.2.2

Complying with the Performance Requirements• Compliance with the Performance Requirements can only be

achieved by:

a) complying with the Deemed-to-Satisfy Provisions; or

b) formulating an Alternative Solution which -

(i) complies with the Performance Requirements; or

(ii) is shown to be at least equivalent to the Deemed-to-Satisfy Provisions; or

a) a combination of a) and b)



Design Flexibility

• The BCA provides two pathways to formulate an Alternative Solution –

− formulating an Alternative Solution to meet the Performance Requirements; or

− formulating an Alternative Solution to at least equate to Deemed-to-Satisfy Provisions.



Flexibility in Compliance

• Either of these options can be explored to establish the most appropriate pathway for a particular Alternative Solution

• A decision regarding the most appropriate approach may be influenced by the views of the Certifying Authority



Consultation

• It is beneficial to discuss an Alternative Solution with the Certifying Authority before lodging an application for approval

• Also discuss the scope of supporting documentation needed• The Certifying Authority can advise on likely Assessment Methods

but should not become involved in development of the design



DEVELOPING ALTERNATIVE SOLUTIONS

Alternative Solutions

• The development of Alternative Solutions was covered in detail in Module Two

• Relevant BCA provisions can be found in Section 1 of Volume Two



ASSESSMENT METHODS

Assessment Methods

• Assessment methods were discussed in detail in Module Two

• Methods for assessing Building Solutions are listed at Part 1.0.9

• The Certifying Authority will assess compliance of Alternative Solutions

• The applicant is required to demonstrate compliance with the relevant Performance Requirements



Four Assessment Methods are listed at Part 1.0.9:

• Evidence of Suitability described in Part 1.2.2

• Verification Methods

• Comparison with Deemed-to-Satisfy Provisions

• Expert Judgement



Assessment Methods


Evidence of Suitability




• Forms of Evidence of Suitability are listed in Part 1.2.2 of Volume Two

• The listed documents generally involve third party mechanisms that may be used to assist either the formulation or assessment of Building Solutions



• Registered Testing Authority report• Certificate of Conformity / current Certificate of Accreditation

• Certification from appropriately qualified persons

• Certification from a body accredited by the Joint Accreditation System of Australia and New Zealand (JAS-ANZ)

• Any other form of documentary evidence





VERIFICATION METHODS

Verification Methods

• A Verification Method is defined as:

− a test, inspection, calculation or other method that determines whether a Building Solution complies with the relevant Performance Requirements

• The definition allows a broad range of processes to be used to verify compliance



Verification Methods

Part 2.6 contains two Verification Methods –• One for energy efficiency of the building shell (V2.6.2.2 – Verification using a reference building)• One for a supply water heater (V2.6.3)• Remember - other Verification Methods may be used



• V2.6.2.2 for a building’s shell applies to:

− a whole Class 1 building

− a whole Class 1 building that incorporates attached and enclosed Class 10a parts, such as attached garages

• It does not apply to detached garages or to open carports



Verification Method V2.6.2.2


• Allows the use of a broad range of Australian and international energy analysis software

• Requires a thermal calculation to show that relevant cooling or heating loads are not greater than than those of the reference building

• Relevant loads vary between climate zones – so check what’s required





• The Method presents specific criteria to be used for modelling

• Criteria are either individually specified, such as space temperature settings, or one of the complying Deemed-to-Satisfy solutions





• Does not cover domestic services – they must be DTS or be demonstrated to comply with P2.6.2 using another Assessment Method

• Uses a reference building

• Requires two computer modelling runs;

− one to set the energy load target(s)

− another to show that each target isn’t exceeded





ADMINISTRATIVE MATTERS

Administrative Matters

• All State/Territory jurisdictions have administrative provisions for the design and construction of buildings

• Energy efficiency is an issue for which specific administrative processes may exist; e.g. accreditation of energy efficiency assessors may be required

• Practitioners need to be aware of relevant processes and ensure they comply

• Alterations, additions and renovations

That's it!

Are there any questions?

module 3 - understanding energy efficiency

Technology

bca scope

bca volumes

bca endeavours

objective of module

content of module

background scope

structures scope

fridges scope