Refusing housing developments on previously-developed land is leaving St Albans wide open to thousands of new homes being built in the Green Belt.

The warning has come from a director of the firm representing the landowners of Hanstead Park in Smug Oak Lane, Bricket Wood, in the wake of a planning committee’s decision last week to refuse outline permission for 138 homes on the site.

Steve Taylor of St Congar Land, which submitted the application for the former HSBC Management and Training Centre, questioned why housing schemes on previously developed land in the Green Belt such as Hanstead Park and the BRE site, also in Bricket Wood, were being refused by councillors.

With a new requirement to build at least 637 new homes in the district annually in the period 2011-31 rather than the 436 on which the district council’s draft planning document, the Strategic Local Plan (SLP), is based, Mr Taylor warned that St Albans council was making it inevitable that greater numbers of housing would have to be in the Green Belt.

He said: “When we bought the site, we thought erroneously that it would be for housing. The alternative is that St Albans council will have to put housing on greenfield sites.

“Eventually they will have to but I think the local authority will resist it as long as possible. If a council can’t grant planning permission on suitable brownfield sites, it is hard to see how they are going to pass the local plan through the Examination in Public and an inspector.”

The draft SLP is currently working on the basis that 437 new homes will have to be built annually in the district and has singled out three potential sites.

The council is proposing 2,500 new homes on land east of Hemel Hempstead and close to Redbourn, 1,000 at Oaklands College in Smallford and 500 in north west Harependen.

But the Department for Communities and Local Government is projecting 637 new homes per annum as a starting point for calculating the district’s housing needs in the period up to 2031.

That has led to fears that as many as 4,000 additional homes will have to be built in the Green Belt to meet the target.

St Albans council turned down 100 new homes on the BRE site in Bricket Wood but it was allowed on appeal and Mr Taylor suspects that the council will also reject 200 homes on the former Harperbury Hospital site - both of which are on previously-developed land.

The Hanstead Park application was turned down on three grounds - the lack of a Section 106 planning agreement which requires a developer to provide funding towards infrastructure such as health facilities, highways and schools, a shortfall in affordable housing and its appropriateness in the Green Belt.

Mr Taylor said he had already submitted an appeal against the decision which followed an earlier refusal of permission for 175 new homes on the site, submitted in 2013.

He added: “We feel we have done as much as we can in the past two years.”