Australia's house of the future needs to be smaller and built for the climate to protect its occupants and the environment according to two of the country's leading architects.
And given Australia has the biggest houses in the world, that's going to mean a fundamental shift in how Australians see a family home.
It could also mean a change in how we live with 2.5 million Australians calling high bushfire regions home, in houses not designed for those conditions.
ECOdesign Architects principal architect Nigel Bell, who is also a member of the bushfire Australian Standards and was an expert witness to the 2020 bushfire Royal Commission, said there were upwards of 900,000 homes across Australia, many with little or no protection for the increasing risks they face in the changing climate.
"We're really now living in an age of consequence. The consequences of too much ignorance or overlooking crucial factors over the last 20, 30, 50 years," Mr Bell said.
Mr Bell spoke as an expert at the Royal Commission in 2020 and said one of the data gathering companies suggested there were "480,000 buildings in Australia in higher extreme (bushfire risk conditions)".
"The Bushfire Building Council said 10 per cent, meaning over 900,000 existing buildings are in high or extreme bushfire risk areas. So pick your statistic: half a million to a million existing homes and families are at risk.
"However, even simple building retrofit against burning embers can make a positive difference."
He said designing for climate had been forgotten about as people turned on air conditioners and heating but with rising electricity costs and changing climate sustainability it was becoming more important.
"We need to look again at climate design basics and consider building comfort and resilience in a warming world."
While there are building standards in place across the country for those building in bushfire-prone areas - the building requirements range from BAL- LOW, which is the lowest risk from potential fire; to BAL - FZ, which is extreme risk where a building is directly exposed to burning embers, heat and the flames from a potential fire front
These standards were primarily only applied to new houses, in building terms, but have having been upgraded since introduced in 2009.
Which meant hundreds of thousands of homes across Australia were sitting in high-risk regions and not built to withstand the fires that might rip through those areas in the future.
Resilient Building Council (formerly Bushfire Building Council of Australia) said $1 trillion worth of Australian property was at risk of bushfire, with 90 per cent of buildings in high risk areas not fire resilient.
It states 2.5 million Australians live in high bushfire risk regions.
Mr Bell said in his local area, the NSW Blue Mountains, 73 to 74 per cent of homes were bushfire prone - and with most built 40 to 50 years ago, they were not built to withstand fires.
"They are typical brick veneer often was tiled roofs, everything that in today's standards is not really bushfire safe."
"It used to be said that people save houses and houses save people. But from the mega files of 2019-20, the intensity and duration has proven that's no longer relevant.
"The whole point of dealing with bushfire emergencies is now public safety: to protect human life by evacuating the area. The house, the buildings, they have to stand on their own merits or fail from their lack of preparation or protection - but now we know how we can do much better."
Building in bushfire-prone areas can be tough, expensive
But getting projects built in those environments could be as difficult - with conflict between environmental protection concerns and land clearing for safety.
"This is where projects are delayed sometimes endlessly, month after month," Mr Bell said.
The back and forth could also lead to ever-increasing costs on the home builder.
Mr Bell said in 2017, AAMI insurance company compared the costs between a standard project home and one in a BAL 40 zone (second highest level on the BAL scale) and found it could add well over $100,000 to the building cost.
If the project was in flame zone (BAL-FZ, the highest level) that could add a quarter of a million dollars to the cost.
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Building small, saves costs and the environment
Despite the benefits of constructing a house for its climate, its still not the main reason people approach an architect - that still comes down to aesthetics and room design.
Australian Institute of Architects incoming national president Stuart Tanner, said people were still focused on what they desired in a house and how they were living, rather than specific climate change measures.
"I think one of the fundamental most important things about responding to climate change is the use of resources," Mr Tanner said.
"The architecture profession is advocating more broadly to building less because one of the largest consumers of waste on the planet is the construction industry itself.
"So the first and foremost, the most fundamental way you can be responsible is to build smaller, consume less materials."
While Europeans build houses of around 65 to 75 metres square and those from the United Kingdom around 147m2, Australian homes loomed large, with a new build home in 2019-20 sitting at an average of 235.8m2.
This love of the large comes at a huge environmental cost - almost 30 per cent of all resource consumption in Australia is from the construction industry (around 20.4 megatonnes of waste was generated between 2016-17).
According to the World Green Building Council's Global Status Report 2022 buildings represented about 37 per cent of global CO2 emissions in 2021. Carbon from buildings operations reached an all-time high with a two per cent increase on the previous peak in 2019.
In Australia, the construction industry spent the most on waste services ($2 billion) in 2018-19, a 35 per cent increase since 2016-17. It was the second-highest generator of waste in 2018-19 creating 12.7 million tonnes or 16.8 per cent of Australia's waste.
By building small homes, less materials were used on the build and there would be less electricity draw going forward. Especially if the house was also built with solar and climate in mind - using techniques such as passive solar gain and thermal mass within the building.
Mr Tanner said good design would allow home owners could use cross ventilation to keep a building cool on a hot day, as opposed to turning on the air conditioning.
"We need to move away from mechanical ventilation and move towards passive ventilation and using cross ventilation and designing our building so that they cool themselves.
"In Northern Queensland you need to be in the breeze and out of the sun, and in Tasmania you need to be out of the wind and in the sun. So an approach to a sustainable building is very different in southern Tasmania than in the tropics."
Mr Tanner said sustainability began with being responsible about building.
"It should also be looking at spaces that utilise light and sunlight and thermal gain as much as we can to create spaces that hold an ambient temperature as much as they can, without using any external sources.
"We should all be aiming to create spaces that inspire us and feed us, nurture us intellectually and physically.
"If we create healthy spaces to live in, then we feel better and then as a society, we operate better. And that comes from good design and good architecture and everyone benefits from good architecture."
As for building costs on a new home, Mr Tanner said it usually depended on where you building, with materials costing more the further they had to travel.
"But a really important thing to bear in mind the actual cost of running a well considered building and a well designed building is going to pay you back over the life lifecycle of that building."