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 buildingβs domestic services and places a limit on the buildingβs 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 (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 mΒ² | Floor area factor |
---|---|
< 50 | 0.0123 |
50β59 | 0.0119 |
60β69 | 0.0116 |
70β79 | 0.0113 |
80β89 | 0.0111 |
90β99 | 0.0108 |
100β109 | 0.0106 |
110β119 | 0.0105 |
120β129 | 0.0103 |
130β139 | 0.0101 |
140β149 | 0.0100 |
150β159 | 0.0099 |
160β169 | 0.0097 |
170β179 | 0.0096 |
180β189 | 0.0095 |
190β199 | 0.0094 |
200β209 | 0.0093 |
210β219 | 0.0092 |
220β229 | 0.0091 |
230β239 | 0.0090 |
240β249 | 0.0090 |
250β259 | 0.0089 |
260β269 | 0.0088 |
270β279 | 0.0087 |
280β289 | 0.0087 |
290β299 | 0.0086 |
300β309 | 0.0085 |
310β319 | 0.0085 |
320β329 | 0.0084 |
330β339 | 0.0083 |
340β349 | 0.0083 |
350β359 | 0.0082 |
360β369 | 0.0082 |
370β379 | 0.0081 |
380β389 | 0.0081 |
390β399 | 0.0080 |
400β409 | 0.0080 |
410β419 | 0.0079 |
420β429 | 0.0079 |
430β439 | 0.0078 |
440β449 | 0.0078 |
450β459 | 0.0077 |
460β469 | 0.0077 |
470β479 | 0.0077 |
480β489 | 0.0076 |
490β499 | 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 | β | β | 2.73 | 3.95 | β | β | β | 4.64 |
2 | β | 1.88 | β | 2.54 | β | β | β | β |
3 | β | β | 1.76 | 3.52 | β | β | β | 4.10 |
4 | β | 2.57 | β | β | 2.65 | β | 1.79 | 3.34 |
5 | β | 2.50 | β | 3.26 | 2.56 | β | β | 3.36 |
6 | β | 3.43 | β | β | 3.58 | β | 2.32 | 4.58 |
7 | 3.66 | 3.32 | β | β | β | 4.41 | 2.32 | β |
8 | β | 5.70 | β | β | β | 5.60 | 4.02 | β |
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 (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 βenergy valueβ 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.
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