Building work is to go on late into the night at the sites of three Bradford schools.

Planners have granted permission to Educo, the contractors working on Bradford Council’s Building Schools for Future (BSF) programme.

Under revised conditions, work can carry on at the new Hanson School and Grange Technology College, in Bradford, and Greenhead High, in Keighley, until 11pm on weekdays.

On weekends, the late deadline applies to Grange but there are earlier time limits on Saturdays and Sundays at Hanson and Greenhead when work must cease at 6pm.

Applications are also pending to extend working hours at Beckfoot School, in Bingley, until 10pm on weekdays and 4pm on weekends. All four schools are being constructed in the second phase of the £400 million secondary school rebuilding project.

Project managers blame the bad weather over Christmas and the New Year for them falling behind on work. Construction has also been hindered by the freezing of underfloor heating pipes. Contractors are still trying to resolve the problem four months on.

A spokesman for Bradford Council said: “The Council received planning applications to revise weekday working hours at the sites of four secondary schools.

“The applications were submitted by the construction contractors Educo, to enable them to reclaim time which was lost during poor weather conditions over the winter. This includes delays caused as a result of frozen water pipes which the contractor is in the process of rectifying.”

With the extra working the Council is confident the phase two schools will be ready on schedule, while neighbours will not be disturbed by noise late at night. The spokesman said: “The Council expects the schools to open on schedule in the spring of 2011.

“The successful applications were approved until the end of the contract. Work outside normal working hours will need to take place indoors with the windows shut to prevent disruption to residents.”

But one objector, a resident of Sutton Avenue near Hanson School, was not convinced.

In a letter opposing the planning application, the resident said: “Even in my back garden the noise is very loud and I can’t put my washing out for the dust coming from your machines. I have to live here with my children and it is very disruptive.”

An resident objecting to the proposed changes affecting the Beckfoot site said: “Whilst I can accept there may be noise pollution during normal working hours, I feel that any extension of those hours into evenings and weekends is totally unacceptable in what is normally a quiet residential area.”