Wests Ashfield Leagues Club & Hotel
The two class groups
Section J assesses this development as two separate class groups, each with its own targets and its own Method 2 weighting coefficients. Every number in this tool belongs to one of them.
Part J4 sets minimum thermal performance for the building envelope: roofs, ceilings, roof lights, walls, glazing and floors, for the applicable climate zone. For walls and glazing, clause J4D6 calls up Specification 37, which offers two Deemed-to-Satisfy routes. Method 1 tests every orientation on its own. Method 2 tests the building as a whole. Passing either one satisfies the NCC.
- Part J4 walls and glazing, both buildings, all four orientations
- Shading as documented on the architectural set
- Wall Total R-values including thermal bridging
- Parts J5 to J9: sealing, air-conditioning, lighting and power, heated water and pool plant, energy monitoring
- Roof, ceiling and floor values are nominated Climate Zone 5 requirements, not calculated
- Existing fabric retained and not altered
The thermal envelope
Before anything can be calculated, the envelope has to be defined: which spaces are conditioned, which walls separate conditioned from unconditioned space, and what is new versus existing. These decisions were agreed with the project team at the Section J workshop and they drive every result that follows.
Only the envelope of a conditioned space is assessed. A wall or window facing an unconditioned space is either excluded or treated as an internal boundary. That makes the conditioning strategy a compliance input, not just a services decision.
Four calculations were prepared: one per building, in each case with and without the internal walls separating the new conditioned works from adjoining unconditioned space.
| Case | Internal walls | Status |
|---|---|---|
| Hotel — assessed basis | Excluded | ADOPTED |
| Club — assessed basis | Excluded | ADOPTED |
| Hotel — alternate | Included | SENSITIVITY |
| Club — alternate | Included | SENSITIVITY |
The façade under test
Two tests, applied four times each. Wall-glazing U-value measures heat flow through the whole façade, glazing and wall together. Solar admittance measures how much solar heat the glazing lets in, after shading. Method 1 needs every orientation to pass both. Click a compass segment to inspect it.
How Method 2 actually works, and why the club’s west façade drops out
1The two tests
Method 2 applies a combined wall-glazing U-value across the building, and an aggregate energy value that weights each orientation’s solar admittance by a coefficient from Specification 37 S37C6. North carries the heaviest weighting because north glazing admits the most annual solar heat in this climate; south carries 1.00. The proposed aggregate must not exceed the reference aggregate, which is the same calculation with the target solar admittance substituted in.
2The 20% rule
Specification 37 excludes any aspect glazed to less than 20% of its façade area from the solar admittance aggregate. The ABCB calculator implements this literally: it sets that aspect’s weighting coefficient to zero. The club’s west façade is 15.9% glazed, so it is excluded from the aggregate on both the proposed and the reference side, while still counting in the combined wall-glazing U-value. Every hotel aspect is more than 30% glazed, so the hotel is unaffected.
3Why the margins are thin
The hotel passes at a combined U-value of 1.9940 against a limit of 2.0, and the club at 1.9900. Both are roughly half a percent inside. That is a deliberate consequence of solving to the limit: it establishes the most relaxed glazing specification that still complies, which is the cheapest compliant façade. It also means any change needs re-checking.
Glazing Lab
The question behind this whole assessment is what glass do I have to buy. Drag the sliders to any product you are considering and this recomputes Specification 37 Method 2 live, against both NCC editions at once. The engine reproduces the four issued ABCB calculators to nine decimal places, so what you see here is what the tool would say.
NCC 2025 readiness
Section J is certified at Construction Certificate stage, not at DA, and the edition in force at the CC application date governs. The project team has advised the CC is anticipated after 1 May 2027, when NCC 2025 becomes mandatory in NSW. That makes NCC 2025, not NCC 2022, the edition the façade should be procured against.
Fabric schedule & next steps
Every building fabric requirement arising from this assessment, in one list, with the party responsible. Tick items off as they are carried into the drawings and the specification — your ticks are saved in this browser.
A short workshop with the architect and the services consultants to walk the schedule and agree ownership and timing of each item. On the basis of this assessment the façade strategy is sound and no performance-based verification is required; the remaining work is documentation and confirmation rather than redesign. In parallel, confirm the CC programme in writing — it determines which glazing specification to procure.
Evidence
The markups and calculator output sheets that sit behind every number in this tool, as issued at Appendices A, B and C of the report. Click any sheet to open it full size.
| Layer | Source | Verification |
|---|---|---|
| Façade geometry, shading multipliers, wall R-values | The four issued REV3 ABCB calculators | 92 / 92 MATCH |
| Specification 37 Method 1 and Method 2 mechanics | ABCB calculator, release V1-7, tool version 1.5 (May 2024) | EXACT TO 1e-9 |
| NCC 2022 targets, Climate Zone 5 | NCC 2022 Volume One, J4D6 and Specification 37 | AS IMPLEMENTED |
| NCC 2025 targets, Climate Zone 5 | NCC 2025 Volume One, Tables J4D6a / c / d | VERIFIED AT SOURCE |
| NSW adoption date, 1 May 2027 | NSW Government release and the ABCB adoption table | VERIFIED AT SOURCE |
| Roof, ceiling and floor R-values | NCC Climate Zone 5 Deemed-to-Satisfy requirements | NOMINATED |
Disclaimer and limitations
This tool presents the preliminary Deemed-to-Satisfy assessment issued as report EN-N26_178 Rev 0.8, 30 July 2026. It is a preliminary issue for client review and not a certification document; it should not be relied upon for Construction Certificate purposes in this revision.
The assessment covers Part J4 building fabric (walls and glazing) only. Parts J5 to J9 are not assessed. Roof, ceiling and floor values are the applicable Climate Zone 5 Deemed-to-Satisfy requirements nominated for the architect to adopt and confirm by construction build-up, not values calculated in this assessment.
Results are conditional on the assumptions recorded in the report and on the shading being retained as drawn. Any change to the façade extent, glazing areas, shading or conditioning strategy requires the assessment to be re-run. Building fabric inputs require verifiable manufacturer data to confirm thermal properties.
The NCC 2025 position is based on the client’s verbal advice that the Construction Certificate is anticipated after 1 May 2027; written confirmation is outstanding. NSW has indicated it will make variations to NCC 2025 on adoption, and no official ABCB NCC 2025 façade calculator has been released at the date of this issue — the NCC 2025 figures should be reconfirmed in that tool once it is published.
Although great care has been taken, IGS does not warrant that this material is free from errors or omissions, and shall not be liable for any loss arising from any person using or relying on it.