Part H6 Energy efficiency

The Objective of this Part is to —

1. reduce energy consumption and energy peak demand; and
2. reduce greenhouse gas emissions; and
3. improve occupant health and amenity.

A building must—

1. reduce the energy consumption and energy peak demand of key energy using equipment; and
2. reduce greenhouse gas emissions that occur as a result of a building’s energy consumption and energy source; and
3. improve occupant health and amenity by mitigating the impact of extreme hot and cold weather events, and energy blackouts.

(1) The total heating load of the habitable rooms and conditioned spaces in a building must not exceed the heating load limit in Specification 44.

(2) The total cooling load of the habitable rooms and conditioned spaces in a building must not exceed the cooling load limit in Specification 44.

(3) The total thermal energy load of the habitable rooms and conditioned spaces in a building must not exceed the thermal energy load limit in Specification 44.

(1) The energy value of a building’s domestic services must not exceed 70% of the energy value with—

1. a 3-star ducted heat pump, rated under the 2019 GEMS determination, heating all spaces that are provided with heating; and
2. a 3-star ducted heat pump, rated under the 2019 GEMS determination, cooling all spaces that are provided with cooling; and
3. a 5-star instantaneous gas water heater, rated under the 2017 GEMS determination, providing all domestic hot water; and
4. a lighting power density of 4 W/m² serving all internal spaces that are provided with artificial lighting.

(2) Domestic services, including any associated distribution system and components must, to the degree necessary, have features that facilitate the efficient use of energy appropriate to—

1. the domestic service and its usage; and
2. the geographic location of the building; and
3. the location of the domestic service; and
4. the energy source.

The Verification Methods in this Part only apply to—

1. a Class 1 building; and
2. an enclosed Class 10a building attached to a Class 1 building.

(1) Compliance with H6P1 is verified when a proposed building—

1. compared to a reference building, using a calculation method other than house energy rating software, has—
   1. in climate zone 1, a cooling load equal to or less than that of the reference building; or
   2. in climate zone 8, a heating load equal to or less than that of the reference building; or
   3. in climate zones 2, 3, 4, 5, 6 and 7, a heating load and a cooling load equal to or less than that of the reference building; and
2. complies with—
   1. for building fabric thermal insulation, clause 13.2.2 of the ABCB Housing Provisions; and
   2. for thermal breaks, clauses 13.2.3(7) and 13.2.5(5) of the ABCB Housing Provisions; and
   3. for floor edge insulation, clauses 13.2.6(4), 13.2.6(6) and 13.2.6(7) of the ABCB Housing Provisions; and
   4. for building sealing, Part 13.4 of the ABCB Housing Provisions or H6V3.

(2) The reference building must comply with the Deemed-to-Satisfy Provisions in Parts 13.2, 13.3 and 13.5 of the ABCB Housing Provisions.

(3) The heating load and cooling load for the proposed building and the reference building must be determined using the same—

1. calculation method; and
2. location specific data, including that of climate and topography appropriate to the location where the proposed building is to be constructed if the data is available, or the nearest location with similar climatic conditions in the same climate zone for which the data is available; and
3. impact of adjoining structures and features; and
4. soil conditions; and
5. orientation; and
6. floor plan, including the location and size of glazing; and
7. number of storeys; and
8. roof cladding and roof lights; and
9. separating walls; and
10. external non-glazed doors; and
11. intermediate floors; and
12. floor coverings; and
13. ventilation; and
14. function and use of the building and spaces, including zoning and hours of occupation; and
15. operating schedules for heating and cooling in Table H6V2a; and
16. cooling thermostat settings of—
    1. for bedrooms, 24°C; and
    2. for habitable rooms other than bedrooms—
       1. in climate zones 1, 2, 3 and 4, 27°C; and
       2. In climate zones 5, 6, 7 and 8, 26°C; and
17. heating thermostat setting of 20°C for all habitable rooms; and
18. occupancy in Table H6V2b, with —
    1. heat gains due to occupants of—
       1. 75 W per person in bedrooms; and
       2. 105 W per person in habitable rooms other than bedrooms; and
    2. occupancy schedules in Table H6V2c; and
19. internal heat gains—
    1. from appliances, 450 W; and
    2. from lighting, 4 W/m²; and
    3. from cooking equipment, in Table H6V2b; and
    4. using the operating schedules for lighting, cooking equipment and appliances, in Table H6V2d; and
20. air infiltration rate—
    1. of 0.75 air changes per hour; or
    2. equal to the intended building air change rate at 50 Pa, divided by 20, where—
       1. an intended building air change rate at 50 Pa is specified; and
       2. additional building sealing provisions to Part 13.4 of the ABCB Housing Provisions are specified; and
       3. building sealing is verified using H6V3.

(4) The calculation method used must comply with ANSI/ASHRAE Standard 140 and be capable of assessing the heating load and cooling load by modelling—

1. the building fabric; and
2. glazing and shading; and
3. air infiltration and ventilation; and
4. the function and use of the building including zoning, hours of occupation, hours of heating and cooling availability and internal heat gains; and
5. relevant built-environment and topographical features; and
6. the sensible heat component of the cooling load and heating load.

(5) Climatic data employed in the calculation method must be based on hourly recorded values and be representative of a typical year for the proposed location.

(1) Compliance with H6P1 is verified for building envelope sealing when a building envelope is sealed at an air permeability of not more than 10 m³/hr.m² at 50 Pa reference pressure when tested in accordance with AS/NZS ISO 9972 Method 1.

(2) Where an air permeability of not more than 5 m³/hr.m² at 50 Pa reference pressure is achieved—

1. a mechanical ventilation system must be provided that—
   1. can be manually overridden; and
   2. provides outdoor air, either—
      1. continuously; or
      2. intermittently, where the system has controls that enable operation for not less than 25 percent of each 4 hour segment; and
   3. provides a flow rate not less than that achieved with the following formula:

      $Q=(0.05\times A+3.5\times (N+1))/p$

      , where—

      1. $Q$

         = the required air flow rate (L/s); and

      2. $A$

         = the total floor area of the building (m²); and

      3. $N$

         = the number of bedrooms in the building; and

      4. $p$

         = the fraction of time within each 4 hour segment that the system is operational; and
2. any space with a solid-fuel burning combustion appliance must be ventilated with permanent openings directly to outside with a free area of not less than half of the cross-sectional area of the appliance’s flue; and
3. any space with a gas-fuelled combustion appliance must be ventilated in accordance with—
   1. clause 6.4 of AS/NZS 5601.1; and
   2. clause 6.4.5 of AS/NZS 5601.1.

(3) For the purposes of (2)(c), the volume of the space is considered to be 1 m³ for determining ventilation requirements.

(1) Where a Deemed-to-Satisfy Solution is proposed, Performance Requirements H6P1 and H6P2 are satisfied by complying with H6D2.

(2) Where a Performance Solution is proposed, the relevant Performance Requirements must be determined in accordance with A2G2(3) and A2G4(3) as applicable.

(1) Performance RequirementH6P1 for the thermal performance of the building is satisfied by—

1. complying with S42C2, using house energy rating software and S42C4(1); or
2. complying with the following parts of the ABCB Housing Provisions—
   1. Part 13.2, for the building fabric; and
   2. Part 13.3, for the external glazing and shading; and
   3. Part 13.4, for building sealing; and
   4. Part 13.5, for ceiling fans.

(2) Performance RequirementH6P2 for the energy usage of the building is satisfied by—

1. complying with S42C3 using house energy rating software and S42C4(2); or
2. complying with Parts 13.6 and 13.7 of the ABCB Housing Provisions for a building with a total floor area not greater than 500 m².