Module 3 - Understanding Energy efficiency

National Construction Code
Training 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 Three
Guide to
Volume One
Volume One
Appendices
Volume TwoVolume One
Plumbing
Code

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 to
Energy 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

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 Map
Figure 1.1.4

Individual State and Territory maps are
available on the ABCB website at:
www.abcb.gov.au
Climate Zone Map

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 Efficiency
Performance 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 Efficiency
Deemed-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 3.12.1
BUILDING 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
floor
0%
walls
8%
roof
5%
doors
0.4%
glazing
87%
Proportion of envelope heat loss
floor
18%
walls
14%
doors
1%
roof
18%
glazing
49%

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 cladding
Roof
light
shaft
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 light
STEP 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 light
shaft
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

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 Floors
Extract 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.

Class
10a
Class 1
Attached Class 10a
Building
Class
10a
Class 1
Class 1Class 10a
Class 1Class 1
Class 10a Class 1
Option (a)
Option (c)(i) Option (c)(ii)
Option (b)

PART 3.12.2
EXTERNAL 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

Table 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
Standard
CU 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
High
CU 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
Standard
CU 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
High
CU 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 3.12.3
BUILDING 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 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 –
• 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

PART 3.12.4
AIR 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 3.12.5
SERVICES

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

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 the
BCA 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)
Solutions

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.
Solutions

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
Solutions

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
Solutions

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
Solutions

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
Solutions

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
Solutions
Assessment Methods

Evidence of Suitability
Solutions

• 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
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
Solutions

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
Solutions

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
Solutions

• 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
Solutions
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
Solutions
Verification Method
V2.6.2.2

• 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
Solutions
Verification Method
V2.6.2.2

• 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
Solutions
Verification Method V2.6.2.2

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!
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questions?

Module 3 - Understanding Energy efficiency

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