Aboriginal housing advocates say the Northern Territory's two-tier system, which leaves most of the NT with no legal requirement for new homes to meet safety or liveability standards mandated for the rest of the country, must change.

The two-tiered building certification system, a model that only exists in the Territory, sees different standards apply in different areas. In the tier-one zones of Darwin, Mparntwe/Alice Springs, and Lake Bennett, all buildings must meet National Construction Code (NCC) requirements and receive full building certification.

In tier-two towns, including Katherine, Tennant Creek and Yulara, all buildings except residential dwellings need to be fully certified.

Then there is the "outside of building control area", which some call the "third tier". In this area, which covers the majority of the Territory, there is no legal requirement to build in accordance with the NCC or the NT Building Act, or even for builders to be licensed.

Skye Thompson, an Arrernte and Kaytetye woman and Aboriginal Housing NT chief executive, says the system must change.

"You should be able to expect the best quality, regardless [of] where you live in the territory," she told the ABC.

In the rest of Australia, building projects are regularly inspected to ensure time and budget pressures are not prioritised over the long-term functionality, equitable access or health and safety of a building.

NT Australian Institute of Architects president and Alice Springs architect Miriam Wallace said "there's no system in place to check the quality of the construction".

"It is wild."

Ms Wallace said in the remote NT building compliance relies on the "goodwill" of everyone involved, with "very little oversight and no legal ramifications".

An NT government spokesperson told the ABC certification was provided for all government building projects outside building control areas, "even though it is not required".

But Ms Wallace claimed that in the absence of a legal framework and on-the-ground independent inspectors, any certification in remote areas is "just a piece of paper".

"For government and builders, who I think mostly mean to do the right thing, they have no independent quality assurance to say 'yes, they are doing the right thing, here's the proof'," she said

In March last year, the federal government announced a 10-year, $4 billion remote housing package for the Northern Territory.

An NT government spokesperson said all homes under this remote housing program would be built in accordance with "relevant Australian standards" and NCC requirements.

Central Building Surveyors director Paul Hinkly said most new government housing out bush was "fairly well compliant", but noted he only inspected government housing "when asked".

"We basically have to rely on what the builder provides us, if they provide us any documentation at all," he said.

Mr Hinkly said non-government construction in the bush could be "very, very dodgy", and he had been urging the NT government to scrap the tiered system.

"You're talking about where people live, where people work," he said.

"Sometimes you think, 'oh my god, how do they get away with that?'"

Ms Wallace said it would not cost much more time or money to enforce tier-one standards across the whole territory.

"We're probably talking about adding one or two per cent to the cost of the house — which is nothing — but [assures] its quality going forward," she said.

She said she feared in remote areas, equitable access — including step-free entries and clearances for wheelchairs — could potentially be scrapped to save money.

Tangentyere Council social policy and research manager Michael Klerck told the ABC he worried the environmental rating of buildings could also suffer under the tiered system.

Despite its extreme temperatures, the NT is the only jurisdiction in the country that has a minimum energy rating of five stars, compared to seven stars in the rest of Australia.

The 2023 CSIRO local government area dashboard showed that out of 437 council jurisdictions nation-wide, Mparntwe/Alice Springs came last with an average star rating of 5.5.

Mr Klerck said those lower ratings were impacting some of Australia's poorest residents, leading to soaring costs for heating and cooling.

"People are making the choice between cooling the house and keeping the fridge on," he said.

Healthabitat director David Donald told the ABC poor quality housing in remote communities was directly linked to worse health outcomes

Surveys conducted by the organisation show nearly 20 per cent of inadequate remote housing is due to poor initial construction, and more than 70 per cent is due to a lack of maintenance.

"I think certification is an incredibly important part," he said.