PROPERTY developers who claim they cannot build affordable houses will have to show their working to the press and public.

New ‘open book’ planning rules will come into force later this year after a ruling by Brighton and Hove City Council’s development committee on Thursday.

It means if builders cannot promise 40 per cent of new units will be affordable – the target set out in the City Plan – their detailed financial plans will be made public for all to see what profit will be made on a new development.

Argus editor Arron Hendy commended the behind-the-scenes work which preceded Thursday’s vote, saying the council’s development and planning teams “should be congratulated” for bringing in a rule to improve transparency.

Currently developers submit “viability assessments” which are independently assessed by the District Valuer Services (DVS).

The figures and assessment are not disclosed to protect commercial confidentiality.

But the lack of transparency has led to criticism, especially in relation to several schemes where councillors have accepted schemes which fall far short of the 40 per cent target.

Now full viability assessment will have to be submitted up front with the rest of the application information.

A public consultation on the issue was held in the autumn.

Most respondents felt the measures would lead to greater transparency, understanding and trust in the planning system.

Developers were concerned commercially sensitive information could be disclosed and this had the potential to hinder development in the city.

Committee chairman Councillor Alan Robins said: “In many cases there may be perfectly good reasons why a developer cannot meet 40 per cent, for example a council might want them to pay for other things such as a new leisure centre.

“But sometimes developers might be trying their luck by raising viability issues.

“Either way, it could be beneficial for the public to have the same information as councillors on the planning committee so that everyone understands why a given amount of affordable housing was accepted or rejected.”

Planning committee chairwoman Julie Cattell has said it would improve the city’s negotiating position in light of recent failures to get developers to make 40 per cent of new homes affordable.

She said: “We want this because we’ve had a lot of developers coming to us half way through the process saying they can’t now afford the 40 per cent affordable figure because the scheme isn’t viable.

“Then we ask them to demonstrate viability and it goes to the independent district valuer service.

“But that happens quite late in the process and it leads to a lot of criticism of decisions we make at planning committee. Having it up front at the stage where they make the application means it’s open and transparent.

“It will help us get a better understanding of where the developers are coming from and puts us in a better negotiating position.”

The new system will start later this year.