HIA Forecasts Tenfold Granny Flat Growth From 2022 to 2026

The Housing Industry Association estimates Australia can build roughly ten times more granny flats in 2026 than in 2022 as states loosen secondary dwelling rules and owners seek rental income on existing blocks. For HIA granny flat growth 2026, Updated 7 July 2026.

Yahoo Finance cited the HIA figure while covering NSW reinstatement of 85 square metre secondary dwellings near Western Sydney International Airport. ABC News reported Planning Minister Paul Scully said about 1,500 residents gain housing choice in Wollondilly, Fairfield, Camden, Liverpool, and Penrith noise zones.

What is driving the build curve

Interest rate pressure, rental shortages, and multi-generational living push homeowners toward backyard units instead of delayed greenfield estates. Complying development pathways in NSW and proposed Tasmanian 90 square metre reforms shorten approval timelines where overlays allow.

Builders report stronger enquiry for transportable and prefab modules on the Mid North Coast, as our Port Macquarie piece noted.

Supply chain cautions for 2026

Tenfold growth strains certifiers, electricians, and plumbers in regional towns. Book trades before ordering shells. Noise attenuation requirements near WSI lower zones add cost lines absent on inner-suburban CDC jobs.

Not every block qualifies

Airport bans remain in Luddenham, Bringelly, and Badgery’s Creek closest to runways. Rural reforms are still policy work in Hawkesbury and statewide NSW responses. Tasmania remains at 60 square metres until amendment enactment.

HIA’s tenfold growth figure assumes states keep loosening secondary dwelling pathways, not that every acreage lot can build tomorrow. Certifier backlogs in regional NSW and Queensland already stretch four to eight weeks in mid-2026, so owners who wait for perfect policy clarity can still face trade shortages when rules finally land.

Prefab suppliers from the Central Coast to the Sunshine Coast report July enquiry up on 2025, but slab and sewer lead times still dominate calendars. Owners comparing granny flat quotes should ask builders for realistic occupancy dates, not brochure timelines tied to HIA’s national forecast.

Western Sydney airport zone owners should still read noise contour rules before assuming HIA growth figures apply on their block.

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