INSIGHT · MATERIALS & COMPLIANCE

A house's energy rating assumes a window.
The quote has to name the same one.

9 October 2026

Under NCC 2022, a house meets its thermal performance requirement either with a house energy rating of at least 7 stars (lower in climate zones 1 and 2 with a qualifying outdoor living area) or through the elemental Deemed-to-Satisfy provisions. Both treat a window as a glazing element whose Total System U-Value and Total System SHGC describe glass and frame together. A window or door quote that names only the glass cannot show that the unit delivered matches the one the rating assumed. Adoption dates for the 2022 housing energy provisions differ by state.

Analysed 9 October 2026 · NCC 2022 Volume Two Part H6, Specification 42 and ABCB Housing Provisions Part 13.3 (ncc.abcb.gov.au) · ABCB NCC 2022 adoption table (correct as at 22 September 2023) and NCC 2025 adoption page · NatHERS window fact sheet (July 2019) · Queensland Modern Homes page · PlanSA national updates page · all pages read 9 October 2026, the Queensland, PlanSA and WERS pages through a rendering proxy because those sites block automated access.

Key takeaways

Two compliance routes, one window description: NCC 2022 Volume Two clause H6D2(1) offers an energy rating using house energy rating software under Specification 42, or the elemental provisions in Parts 13.2 to 13.5 of the ABCB Housing Provisions, with Part 13.3 covering external glazing and shading. Both describe a window by performance values for the whole unit.
Glass and frame are rated together: The NCC's explanatory information states that Total System U-Values and Total System SHGCs are assessed for the combined effect of glass and frames, measured under the Australian Fenestration Rating Council (AFRC) protocols, and that values published as 'U Factor' or 'Uw' can be used provided they measure combined glass and frame performance.
A default window in a rating comes with a tolerance: The NatHERS fact sheet (July 2019) states that where a default window is used in an assessment, an allowable tolerance for the U-value and SHGC is shown on the Universal Certificate and the final window product will need to conform within that range.
The 2022 housing energy dates were not national: The ABCB's adoption table, correct as at 22 September 2023, lists housing energy efficiency from 1 October 2023 (NSW, through enhanced BASIX) to 1 May 2025 (WA), refers Queensland to its own site (which states 1 May 2024) and records Tasmania as not adopting the NCC 2022 housing energy efficiency requirements.
We would carry the rating's numbers on every line: A system-design recommendation: each window line on a quote and order holds its Uw and SHGCw, where those values came from, and the certificate value or tolerance it has to meet, so a change of glass or frame is checked against the rating before it is made.

Two ways a house meets the energy rules,
and where the window sits in each.

Clause H6D2(1) of NCC 2022 Volume Two states that Performance Requirement H6P1, for the thermal performance of the building, is satisfied either by complying with S42C2 using house energy rating software and S42C4(1), or by complying with Part 13.2 (building fabric), Part 13.3 (external glazing and shading), Part 13.4 (building sealing) and Part 13.5 (ceiling fans) of the ABCB Housing Provisions.

The frame enters the elemental calculation twice: through the Total System values, and through a frame factor for frame colour. The Housing Provisions explain that the darker the window frame, the greater the solar heat gain through the frame.

The energy rating route: S42C2(1) requires an energy rating, including separate heating and cooling load limits, of 7 stars or more; or, in climate zones 1 or 2, 6.5 stars with a qualifying outdoor living area under an impervious roof of Total R-Value 1.5 or more, or 6 stars with that roof and at least one permanently installed ceiling fan. The windows are part of what the software models.
The elemental route: Part 13.3 applies to a Class 1 building and a Class 10a building with a conditioned space. Clause 13.3.2, for climate zones 2 to 8, limits the ratio of conductance to solar heat gain of the glazing in each storey, calculated from the area, Total System U-Value and Total System SHGC of each glazing element with factors for orientation, room type, frame and floor.

Total System values:
the number belongs to the unit, not the glass.

The explanatory information to clause 13.3.3 (summer glazing) states that, by referring to glazing elements, the clause requires Total System U-Values and Total System SHGCs to be assessed for the combined effect of glass and frames; clause 13.3.2 uses the same Total System terms. Their measurement is specified in the AFRC's Technical Protocols and Procedures Manual for Energy Rating of Fenestration, for glazing elements of representative size and arrangements.

Uw and SHGCw: The same text notes that assessors using AFRC procedures may publish values as 'U Factor' or 'Uw' for Total System U-Value, or 'SHGC' for Total System SHGC, and that such values can be used under 13.3.3 provided they measure the combined glass and frame performance according to AFRC requirements. A glass-only U-value is a different number.
Who sets the protocols, who runs the scheme: The AFRC describes its role as developing, administering and approving comparative energy and related rating programs for windows, doors, skylights and attachment products. The Window Energy Rating Scheme (WERS) website is published by the Australian Glass and Window Association (AGWA), and its home page links to residential, commercial, skylight and film rating searches.
The WERS data has a use notice: As read on 9 October 2026, the WERS home page states that automated scraping, harvesting, crawling, downloading, indexing or extraction of WERSLink data by any means, including AI systems and bots, is prohibited without AGWA's prior written consent.

Inside a NatHERS rating, a window is
a named product or a default with a range.

The Nationwide House Energy Rating Scheme (NatHERS) fact sheet on windows, dated July 2019, describes two groups of windows available to an assessor in NatHERS software.

The fact sheet states twice that the NatHERS window codes are for software identification only and are not codes used to order windows from a builder or window supplier. The rating and the order are linked by values, not by a part number.

Custom windows: Actual windows available on the market in Australia, in a library managed and provided to software developers by the AFRC. The fact sheet states there are over 10,000, and that a custom window used in an assessment is displayed on the Universal Certificate and can be checked off for compliance.
Default windows: Statistically derived windows for use when full window information is not available at the time of rating: 136 of them, from six frame types and 12 glazing types. For example, the fact sheet lists ALM-001-01 A, an aluminium Group A window with single clear glazing, at Uw 6.7 and SHGCw 0.57.
The tolerance is the link to the order: Where a default window is used, an allowable tolerance for the U-value and SHGC value is shown on the Universal Certificate, and the final window product will need to conform within that range.

When each state adopted the 2022
housing energy provisions.

The ABCB states that 1 May 2023 marks the adoption of NCC 2022, with transition arrangements for some requirements. Its table of state and territory dates is described as correct as at 22 September 2023. For housing energy efficiency it lists:

Queensland's page states that new houses and townhouses must achieve 7 stars in most cases, 5 stars for eligible small homes and 6 stars for eligible houses with raised floor construction under Queensland Development Code 4.1. A state's star requirement and its date both belong in the record of which rule a rated house was assessed under.

Jurisdiction	Housing energy efficiency, as listed by the ABCB (correct as at 22 September 2023)
Australian Capital Territory	From 15 January 2024
New South Wales	Enhanced BASIX from 1 October 2023
Northern Territory	Limited to 5-star requirements from 1 October 2023
Queensland	Refers to the Queensland Modern Homes website, which states the residential energy efficiency standards under NCC 2022 commenced on 1 May 2024
South Australia	1 October 2024
Tasmania	NCC 2022 housing energy efficiency requirements not adopted
Victoria	1 May 2024
Western Australia	1 May 2025

NCC 2025 arrives on different dates again.

The ABCB states that NCC 2025 was published on 1 May 2026, and that some requirements may apply at different times or not at all because of state or territory variations. PlanSA reports that Building Ministers, meeting on 22 October 2025, agreed that further electric vehicle charging provisions and residential changes would not be introduced in NCC 2025.

The ABCB defines the Building Code of Australia (BCA) as NCC Volumes One and Two, and the Plumbing Code of Australia (PCA) as Volume Three. For a window manufacturer selling into several states, the edition a house was assessed under is a field on the job, not a constant.

Jurisdiction	NCC 2025 adoption, as listed by the ABCB	Transition period
Australian Capital Territory	1 May 2026	12 months
New South Wales	1 May 2027	N/A
Northern Territory	Not adopted	N/A
Queensland	1 May 2027	N/A
South Australia	BCA: 1 May 2027; PCA: 1 May 2026	N/A
Tasmania	1 May 2027 (temporarily adopted 1 May to 4 June 2026)	5 June 2026 to 1 May 2027
Victoria	1 May 2026	N/A
Western Australia	1 May 2026	12 months

What we would put in a system

The link between a rating and a delivered window is a set of values that has to survive quoting, ordering, substitution and installation. In our experience, a window quote is built from a frame series and a glass specification, and the energy rating sits with the builder or the assessor, not with the manufacturer. For each window line, we would test for four fields.

Where agents help is narrow. A document intelligence agent can read a window schedule, a NatHERS certificate and the manufacturer's own rating documents, extract each opening's values and tolerance, and draft the quote lines and a substitution check; a person confirms them. No agent decides whether a window complies, whether a substitution is acceptable or whether a house meets the NCC. Those are for the assessor, the building certifier and the builder.

Field	Why it is load-bearing
Opening reference matching the plan and the rating	The certificate shows the custom windows, or the tolerance for default windows, that the rating used. Without the same reference, a quote line cannot be compared with what it has to meet.
Uw and SHGCw for the whole unit, with their source	The NCC uses Total System values for glass and frame combined, measured under AFRC protocols. A glass-only figure is a different number. The source is the rating document the manufacturer holds for that product.
The certificate value or tolerance the unit must meet	For a default window the Universal Certificate shows an allowable U-value and SHGC range; for a custom window it shows the product. Either is the acceptance test for the order.
State, NCC edition and the date of the job's assessment	The 2022 housing energy provisions began on different dates in each state, Tasmania did not adopt them as at the ABCB table, and NCC 2025 adoption dates also differ.

Questions worth asking
of your own quotes

For a window manufacturer: does each quote line carry a Uw and SHGCw for the whole unit, or only the glass description?

The NCC's elemental provisions and NatHERS both work with Total System values for glass and frame combined. A line that only names the glass cannot be checked against a certificate.

For an estimator: when a builder asks to change the glass or the frame colour, what is the change checked against?

If the rating used a default window, the Universal Certificate shows the allowable range. In the elemental calculation, frame colour also enters through a frame factor. The check needs the certificate, not just the price difference.

For a builder ordering windows: has the manufacturer seen the NatHERS certificate for the job?

The certificate holds the values the delivered windows need to meet. If it stays with the assessor and the builder, the manufacturer quotes to a drawing and the match is checked, if at all, after delivery.

For anyone selling into several states: which NCC edition and which state date applies to each job?

The ABCB lists NCC 2022 housing energy dates from 1 October 2023 to 1 May 2025 (table correct as at 22 September 2023), and NCC 2025 dates from 1 May 2026 to 1 May 2027. The job's assessment date and state decide which applies.

Questions people ask
about window energy ratings

What U-value do windows need to meet under NCC 2022?

NCC 2022 does not set one window U-value for houses. Under the energy rating route, the house as a whole must achieve at least 7 stars, or 6.5 or 6 stars in climate zones 1 and 2 with a qualifying outdoor living area (S42C2), subject to state variations, with the windows modelled inside the rating. Under the elemental route, Part 13.3 limits the glazing's combined conductance and solar heat gain per storey, calculated from each window's Total System U-Value and SHGC.

What is the difference between Uw and a glass U-value?

The NCC's explanatory information in Part 13.3 states that Total System U-Values and SHGCs are assessed for the combined effect of glass and frames under AFRC protocols, and that values published as 'Uw' can be used if they measure combined glass and frame performance. A glass-only U-value does not include the frame.

What is WERS?

The Window Energy Rating Scheme is published on wers.net by the Australian Glass and Window Association, with rating searches for residential and commercial windows, skylights and films. The AFRC, whose board includes AGWA, develops and approves the rating protocols the NCC refers to.

When did the NCC 2022 housing energy rules start in each state?

The ABCB's table, correct as at 22 September 2023, lists NCC 2022 housing energy efficiency from 15 January 2024 in the ACT, 1 October 2023 in NSW through enhanced BASIX, 1 May 2024 in Victoria, 1 October 2024 in South Australia and 1 May 2025 in WA. Queensland's site states 1 May 2024. The NT is listed as limited to 5-star requirements, and Tasmania as not adopting.

Does NCC 2025 change the energy rules for windows in houses?

PlanSA reports that Building Ministers agreed on 22 October 2025 that "further electric vehicle (EV) charging provisions and residential changes" would not be introduced in NCC 2025, while residential condensation mitigation provisions were included. We did not compare NCC 2025 Part 13.3 with NCC 2022. The ABCB lists NCC 2025 adoption dates from 1 May 2026 (ACT, Victoria, WA) to 1 May 2027 (NSW, Queensland, Tasmania, and the BCA in South Australia).

What this analysis
does and does not show.

Evidence note

What it shows: How NCC 2022 and NatHERS describe a window for a house's energy compliance (Total System U-Value and SHGC for glass and frame together, under AFRC protocols), the tolerance a default window carries on a NatHERS certificate, and the state adoption dates published by the ABCB, as they bear on the records a window or door manufacturer's quote and order need to carry.
Key facts quoted: H6D2(1) two routes; S42C2(1) 7 stars, or 6.5 or 6 stars in climate zones 1 and 2 with conditions; Part 13.3 applies to Class 1 and Class 10a with a conditioned space; Total System values under AFRC protocols, 'Uw' accepted if combined glass and frame; NatHERS: over 10,000 custom windows, 136 default windows, tolerance shown on the Universal Certificate; ABCB NCC 2022 housing energy dates (table correct as at 22 September 2023); Queensland 1 May 2024; NCC 2025 published 1 May 2026 with dates to 1 May 2027.

The ABCB NCC 2022 adoption table states it is correct as at 22 September 2023. We did not confirm each state's position after that date, except Queensland's own page. In particular we did not read a current Tasmanian source; the Tasmanian regulator's NCC 2022 page returned page not found on 9 October 2026.
The NatHERS window fact sheet is dated July 2019. We did not read the current NatHERS Technical Note or certificate specification, and the tolerance description is as the fact sheet states it.
We did not read the AFRC protocols or the ABCB Standard for NatHERS Heating and Cooling Load Limits, and quote neither.
The Queensland, PlanSA and WERS pages were read through a rendering proxy on 9 October 2026 because those sites block automated access. We did not open WERSLink rating searches.
We make no statement about any product's ratings and do not determine whether any window, substitution or house complies.
Nothing here is legal or building certification advice.

What to watch next

Publisher-announced dates only.

1 May 2027: NCC 2025 adoption in New South Wales and Queensland, the BCA in South Australia, and Tasmania, as listed by the ABCB. Tasmania's listed transition period ends on the same date.
12-month transitions from 1 May 2026: The ABCB lists a 12-month transition period for NCC 2025 in the Australian Capital Territory and Western Australia, both adopting from 1 May 2026.

Bring us one window schedule and its energy rating certificate.

Send the schedule, the NatHERS certificate or elemental calculation, and the quote you issued. We will show you which lines carry the values the rating relies on, and which would need checking before a substitution.

This article is general information about the National Construction Code, NatHERS and published state adoption dates. It is not legal or building certification advice, and it does not determine whether any window, substitution or house complies. All dates and quotations are as read on 9 October 2026 from the sources listed, and the ABCB's NCC 2022 adoption table is correct as at 22 September 2023 by its own statement.

Send us the schedule · Quoting

Sources

Suggested citation: NCC 2022 Volume Two Part H6, Specification 42 and Housing Provisions Part 13.3; ABCB NCC 2022 and NCC 2025 adoption pages; NatHERS window fact sheet (July 2019), as read 9 October 2026. No figure is derived; all values and dates are quoted as published.

A house's energy rating assumes a window. The quote has to name the same one.