Big developers are cashing in on ‘dodgy’ data that could leave new housing blocks overcrowded and without enough children’s play areas, campaigners have claimed.

Haringey Defend Council Housing (HDCH) says developers are using out-of-date guidelines to work out the number of children that are expected to live in the new buildings – the “child yield”, in planning jargon.

This means they underestimate the number of children people are likely to have – and do not have to put in as many play spaces for youngsters.

HDCH’s Paul Burnham and Jacob Secker made the claims at a meeting of Haringey Council’s housing scrutiny panel on Tuesday (January 15).

Mr Burnham told councillors that developers were using policy “for their ends to create more profit for themselves and very adverse impacts for ordinary people”.

He said: “The reality is, these developments are going to be overcrowded, and children are going to be growing up in inadequate, overcrowded households.”

Mr Burnham said he had questioned child yield data with the Greater London Authority (GLA) and was told by a senior planner that updated guidelines had been released and should be in use.

He said that while it was a London-wide problem, he wanted Haringey to take the lead in agreeing to use the correct figures and calling on the GLA to do the same.

The east of the borough in particular has seen a large number of new developments approved in recent years, including the Tottenham Hale District Centre and High Road West schemes.

Mr Burnham said using the out-of-date guidelines predicts the Tottenham Hale development would have just 63 children living in 900 market-sector homes – many of which are two and three-bedroom flats.

But using the updated way of calculating child yield gives figures of between 104 and 269 children for that development.

He said the updated guidelines were released by the GLA at the end of 2017, but the older figures were continuing to be used across London.

Mr Secker described the situation as “a fiddle”.

He said: “It is going to mess up your school figures, because presumably you won’t have proper figures for how many school places are needed, and it’s part of a general policy in this country of making life hell for anyone who wants to bring up children.”

“Haringey council can make a difference.”

But Emma Williamson, the council’s assistant director of planning, said the GLA had told her the council was using the correct figures for calculating children’s play space.

She added that if the council wanted to use new figures, it may have to carry out a local planning review first.

Ms Williamson also disputed HDCH’s claims that the child yield figures would affect the payments developers would have to make to fund schools and other improvements in the local area.

Councillor Yvonne Say, Labour member for Bounds Green, said: “Is it possible we can recommend we adopt the new figures as soon as possible and ask cabinet to make that happen?”

Cllr Dawn Barnes, Liberal Democrat member for Crouch End, said: “I would agree. In terms of tackling diabetes and childhood obesity, for example, play space is absolutely critical.

“If Haringey can lead the way in giving places for our kids to play, given that many of them grow up in flats, I think that would be great.”

The panel unanimously agreed to ask cabinet to adopt the updated figures.