Substandard windows that fail to meet Australian safety standards are still being installed in new homes, sparking fresh concerns about imported building products.

There’s a push to limit cheaper Chinese products, but fears are growing they’re still flooding the market through a backdoor.

WATCH THE VIDEO ABOVE: Dodgy windows flooding Australian market through backdoor

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While glass is transparent, clarity may be lacking in the origin of the imported windows that end up in Australian homes and workplaces.

In just six months, imports from Vietnam to Australia have spiked a staggering 1700 per cent.

Local manufacturers want Australian authorities to investigate whether these are actually Chinese products being made to look Vietnamese.

“It certainly indicates a change in behaviour and warrants investigation,” Clinton Skeoch from the Australian Glass & Windows Association said.

Cheap Chinese building materials failed Australian safety standards in alarming tests earlier this year. Credit: 7NEWS

Domestic manufacturers have raised concerns about Chinese imports after industry-commissioned testing earlier this year found 87 per cent of imported products tested failed Australian standards.

Australia’s Anti-Dumping Commission is separately investigating whether there’s been a flood of cheaper Chinese imports.

If dumping is proved, the government can charge extra duties on Chinese imports.

“Potentially, some of these Chinese exporters are rerouting their windows through Vietnam to try and circumvent any potential anti-dumping measures that the Australian government may take,” Scott Kelly from Ventora Windows & Doors said.

In just six months, imports from Vietnam to Australia have spiked a staggering 1700 per cent. Credit: 7NEWS

However, other Australian companies argue parts they get from China are simply a decent product at a better price, and now Vietnam offers that too.

“If a duty is applied, then the Australian public will pay that duty. Nobody else,” Ed Stelling from EcoEco Windows & Doors said.

With initial findings due next month, Australians could soon get a window into who is right.