Building costs & energy data · Australia · 2026

How much extra does a 7-star home cost in Australia?

Published estimates range from $710 for a Queensland Class 1 dwelling in Australian Building Codes Board modelling, expressed in 2021 dollars, to $3,310 for a single-storey, four-bedroom Victorian house in a government worked example. The Housing Industry Association produced a much higher adjusted estimate of $13,257 per dwelling under Option A, but the figures use different methods and are not directly comparable.

NCC 2022 lifted the model thermal-performance requirement for new homes from 6 stars to the equivalent of 7 stars and introduced a separate Whole of Home energy-use budget. States and territories adopted the changes at different times and with local variations.

There is no official national average cost premium. Industry and consumer groups disagree on whether the added cost is outweighed by lower energy bills and other benefits. NCC 2025 introduced no further residential energy-efficiency changes, and most additional residential code changes are paused until mid-2029.

SECTION 01 · Standard

What does the 7-star home energy standard require?

The NCC 2022 residential energy provisions generally require two separate performance outcomes: thermal performance equivalent to 7 NatHERS stars and compliance with a Whole of Home annual energy-use budget. The 7-star rating measures the building shell, while Whole of Home is a separate score.

Under the NCC 2022 NatHERS pathway, houses generally require a Whole of Home score of at least 60 out of 100, while apartments generally require at least 50. Alternative compliance pathways, state and territory variations and local concessions may apply.

Features commonly identified in government guidance include north-facing living areas, reduced east and west-facing glass, shading, low-e or tinted glazing, roof and wall insulation, lighter-coloured roofs and walls, and ceiling fans. Victorian guidance identifies better design and orientation, improved insulation and higher-performance glazing as common differences between 6-star and 7-star homes.

There is no single fixed package. The thermal performance outcome depends on climate, orientation, building design, insulation and glazing. The Whole of Home score is affected by heating and cooling, hot water, lighting, cooking, plug-in appliances, pool and spa equipment, rooftop solar and battery storage.

Source: NatHERS, Introducing Whole of Home ratings, 23 March 2023; Queensland Government residential energy-efficiency standards; Victorian Government 7-star energy-efficiency building standards.

SECTION 02 · Cost

How much more does a 7-star home cost than a 6-star home?

Reported premiums for the 7-star uplift range from $710 to $13,257 per dwelling, with the highest estimate almost 19 times the lowest. Three estimates exist, each using a different method, home design and location, and none of them represents a single national figure.

Source: ABCB, NCC 2022 Residential Energy Efficiency: Final Decision RIS, July 2022; Victorian Government household guidance; HIA submission to the Consultation RIS, 2021. ABCB figures are expressed in 2021 dollars.

A separate, earlier Queensland Government study modelling the state's move from its own QDC 4.1 standard up to the national NCC 2019 6-star benchmark — not the 7-star standard discussed above — illustrates how much design, climate zone and orientation can affect upgrade costs:

• an earlier Queensland uplift study found a two-storey house design cost more to upgrade as the climate zone number increased, $3,998 in zone 2 rising to $7,745 in zone 5, while an older-style Queenslander design moved the opposite way, $12,040 in zone 2 falling to $9,286 in zone 5
• orientation alone moved the estimated cost by nearly $8,000 for the same design in the same climate zone, from $2,188 facing north to $10,135 facing west
• glazing was the largest single cost driver in three of the four Queensland house designs tested, well ahead of insulation
• more than 58% of affected dwellings in that earlier study showed an absolute reduction in construction cost, even with no change to the dwelling design, so cost is not automatically higher under a tighter standard

SECTION 03 · States

How 7-star home requirements differ by state and territory

Six of Australia's eight states and territories have adopted 7-star-based requirements, with implementation dates spanning 19 months from October 2023 to May 2025. Tasmania and the Northern Territory have not adopted the 7-star minimum, while several adopting jurisdictions apply local variations, exclusions or concessions.

Source: ACT, Victorian, Queensland, NSW, South Australian, Western Australian, Tasmanian and Northern Territory government guidance, 2023 to July 2026.

State and national milestones, 2023 to 2029

Nine milestones trace the implementation of the 7-star-based requirements from October 2023 and the pause on most further residential changes until mid-2029.

SECTION 04 · Payback

How long does it take for a 7-star home to repay the extra cost?

The simple payback period is about 11 years in the Victorian Government's worked example. There is no official national payback figure, and the result depends on the upfront cost, annual energy savings and financing assumptions.

SECTION 05 · Savings

How much can a 7-star home save on energy bills?

Published estimates of energy bill savings vary because they measure different combinations of thermal performance, appliances and rooftop solar. Selected government estimates for houses range from about $183 to at least $300 a year, while broader independent modelling reports savings above $1,000 a year.

The differences between the government and Renew estimates mainly reflect their scope. The government figures describe selected minimum-compliance or regulatory examples, while Renew's modelling includes efficient appliances and rooftop solar. Differences in energy prices, dwelling design and modelling assumptions may also affect the results.

These savings are being reported against real bill pressure. In the 12 months to May 2026, the Australian Bureau of Statistics recorded electricity prices up 21.1%, or 3.9% excluding Commonwealth and state rebates, while new dwelling prices rose 5.6%, driven mainly by project home builders passing through higher labour and materials costs.

SECTION 06 · Debate

Why builders and consumer groups disagree about 7-star home costs

The 2021 Consultation Regulation Impact Statement estimated national net costs of $2.366 billion under one scenario and $1.795 billion under another. HIA's adjusted modelling estimated higher net costs of $12.894 billion and $8.160 billion, while Renew modelled annual household savings above $1,000 for a broader package including efficient appliances and rooftop solar. These figures measure different outcomes and are not directly comparable.

Where the debate sits now

The broader NCC Modernisation Project received 213 submissions. The review found broad agreement on problems including complexity, cost and inconsistent compliance, but disagreement over the solutions. Its final report is due in late 2026, while most further residential NCC changes are paused until mid-2029, except for essential safety and quality measures.

Source: Home Energy Rating (NatHERS) household guidance; Victorian Government household guidance.

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