Plastic pollution threatens to wipe 7.4 per cent off the value of Sydney homes in areas where litter is apparent, a new report shows.

The report, released by Boomerang Alliance, found that if just 5 per cent of 1.6 million homes in Sydney neighbourhoods are adversely affected by litter, the potential economic impact on housing in Sydney is $11.8 million.

It based its findings on a model developed in the US by the National Association of Home Builders, who determined the presence of litter devalued property in that neighbourhood by about 7.4 per cent.

These figures don't surprise the Property Council of Australia.