City Hall may have found a way to finally get hundreds of much-needed homes built after new pollution rules stopped construction.

For nine months, a government mandate has meant no new houses could be built in Norwich, to prevent excess nutrients from getting into the waterways and disrupting the wildlife.

Now the city authority has suggested 'mitigation credits’ that housebuilders can buy as one way to help get construction back up and running again.

The 'nutrient neutrality' measure, laid down by Natural England, is intended to stop large quantities of nitrogen and phosphate from harming protected species in the River Wensum and the Broads.

Eastern Daily Press: Councils have not been able to grant permission for thousands of homes in Norfolk Picture: Chris BishopCouncils have not been able to grant permission for thousands of homes in Norfolk Picture: Chris Bishop (Image: Chris Bishop)

The credits would work similarly to those used for carbon emissions, where businesses can buy the right to emit a set amount of CO2.

The credits will be created by making council homes more water efficient, reducing the quantity of nutrients entering Norfolk’s waterways. 

A total of 52 development sites in Norwich are held up in the planning process which, if permission was granted, would release 1,623 new dwellings, including 1,100 at Anglia Square. 

A report to Norwich City Council's cabinet said: “When retrofitting water-saving appliances, the water usage saved from the retrofitted properties will be replaced by the additional water from new dwellings.

"As a result, the volume of water entering the treatment works will stay the same and providing the treatment works operate to a permit limit, the effluent discharge concentration remains the same.” 

The majority of credits are likely to be created by retrofitting council houses, but care providers have also been suggested as a source.

The council owns around 14,500 properties.

The total costs of the work, including new toilet, taps and shower efficiency improvements are expected to be around £1,450 per property.

Roughly three retrofit houses would be needed to generate enough water efficiency savings for one new home to be built.

All Norfolk councils have been affected in part by the measure, but Norwich is entirely covered by nutrient neutrality.

Developers are also exploring on-site mitigation but they are unlikely to be able to provide sufficient measures on large-scale sites.

The cabinet is expected to agree to pursue using mitigation credits and retrofitting homes at a meeting on Wednesday.