J1P3 Performance Requirements

J1P3 Energy usage of a sole-occupancy unit of a Class 2 building or a Class 4 part of a building sets the energy value requirement for a building’s domestic services and places a limit on the building’s annual energy use budget based on the societal cost of energy use. This energy value is the Performance Requirements and set on an SOU by SOU basis.

To meet J1P3, the DtS Provisions J2D1 offer a mechanism for compliance. Under J2D2(3), there are two compliance options: net equivalent energy usage calculation, per J3D14, or using house energy rating software according to J3D15, with a whole-of-home rating not less than 50.

Compliance involves ensuring that the energy usage of a proposed house or apartment (Step 2) is equal to or less than the energy use budget (Step 1). A series of calculations are necessary to determine compliance (Step 3).

Step 1 - Energy Use Budget

The energy use budget (allowance) is based on the floor area of the apartment and its location.

The following calculation is used to determine the energy usage of a proposed apartment, where:

$$A \times EF$$

• A (Floor Area Factor): Multiply the total floor area by the adjustment factor from Table J3D14a.

• EF (Energy Factor): Obtain this from Table J3D14b.

Table J3D14a Floor area adjustment factor for a sole-occupancy unit of a Class 2 building or a Class 4 part of a building

Total floor area m²	Floor area factor
< 50	0.0123
50–59	0.0119
60–69	0.0116
70–79	0.0113
80–89	0.0111
90–99	0.0108
100–109	0.0106
110–119	0.0105
120–129	0.0103
130–139	0.0101
140–149	0.0100
150–159	0.0099
160–169	0.0097
170–179	0.0096
180–189	0.0095
190–199	0.0094
200–209	0.0093
210–219	0.0092
220–229	0.0091
230–239	0.0090
240–249	0.0090
250–259	0.0089
260–269	0.0088
270–279	0.0087
280–289	0.0087
290–299	0.0086
300–309	0.0085
310–319	0.0085
320–329	0.0084
330–339	0.0083
340–349	0.0083
350–359	0.0082
360–369	0.0082
370–379	0.0081
380–389	0.0081
390–399	0.0080
400–409	0.0080
410–419	0.0079
420–429	0.0079
430–439	0.0078
440–449	0.0078
450–459	0.0077
460–469	0.0077
470–479	0.0077
480–489	0.0076
490–499	0.0076
500	0.0075

Table J3D14b Energy factor for a sole-occupancy unit of a Class 2 building or a Class 4 part of a building

Climate zone	ACT	NSW	NT	QLD	SA	TAS	Vic	WA
1	—	—	2.73	3.95	—	—	—	4.64
2	—	1.88	—	2.54	—	—	—	—
3	—	—	1.76	3.52	—	—	—	4.10
4	—	2.57	—	—	2.65	—	1.79	3.34
5	—	2.50	—	3.26	2.56	—	—	3.36
6	—	3.43	—	—	3.58	—	2.32	4.58
7	3.66	3.32	—	—	—	4.41	2.32	—
8	—	5.70	—	—	—	5.60	4.02	—

When undertaking J1V5 modelling on Speckel, this step is automated.

Step 2 - Proposed Energy Usage

The energy usage of a apartment is calculated using several factors, including:

• Floor area of the house or apartment

• Main heating and/or cooling equipment

• Main water heater

• Swimming pool

• Spa

• On-site photovoltaics

The following formula is used to calculate the energy usage of a proposed apartment, where:

$$(A \times EE) + EP + ES - ER$$

• A (Floor Area Factor): Multiply the total floor area by the adjustment factor from Table J3D14a.

• EE (Efficiency Factor): Obtain the main space conditioning and main water heater efficiency factor from the ABCB Standard for Whole-of-Home Efficiency Factors.

• EP (Pool Pump Energy): The swimming pool pump energy usage.

• ES (Spa Pump Energy): The spa pump energy usage.

• ER (Photovoltaics Reduction): The installed capacity of on-site photovoltaics apportioned to the sole-occupancy unit of a Class 2 building or Class 4 part of a building (kW).

This calculation provides the total proposed energy usage, which is then compared to the energy use budget for compliance.

The factors are detailed in the ABCB Standard for Whole-of-Home Efficiency Factors and a series of lookup tables in the NCC.

Step 3 - Report Energy Use per SOU

Each SOU must report its energy usage to compare against the energy use budget (allowance).

Calculating the ‘energy value’ to comply with J1P3 is not required in most cases, except where a Performance Solution that uses an energy value is developed using a first-principles approach. Compliance options that can be used to meet this Performance Requirement are discussed in section 2.4.

Alternatively, a performance solution can be utilised to confirm compliance with J1P3. Since the performance requirements are quantified, the performance solution must also be quantified to directly meet the performance requirement or demonstrate equivalence with the DtS provisions.