Major concerns have been expressed about the “unacceptable” amount of school days being lost across the Bradford district because of over-running building work.

And there are calls for teachers to come in and make up for lost time during school holidays after it emerged that 11 primary schools out of 28 that underwent summer building work failed to reopen on time at the start of the current academic year in September.

Now Councillor Ian Greenwood, the leader of Bradford Council, has admitted that the practices for recruiting builders were not up to scratch and must be improved.

Following a question from the Telegraph & Argus, the Council has revealed that 518 days were lost from September 2010 to this August in primary and secondary schools and academies, because of snow, strikes, burst pipes, heating failures and building works.

The worst-hit schools so far this year include Newhall Park Primary School, in Bierley, Bradford, which was closed to reception pupils for an extra ten days and year 1 pupils for five days following the summer break.

Builders were changing the internal layout of the school to make the classes bigger to cope with a growing population of school children.

The problems were revealed by Coun Greenwood after Councillor John Ruding (Lab, Tong) asked how many schools failed to reopen on time.

“I happen to know that builders were still on site at Newhall School until mid-October because I am a governor there – for me that is completely unacceptable,” Coun Ruding said.

“I am quite happy to say that it is appalling that the Council procurement system cannot take a six-week contract and deliver on time. That would be completely unacceptable in a private company.

“Every single day of a child’s education is precious and important. Schools should open in the holidays to get these days back.”

Coun Greenwood said that the figures were of concern and that the Council was looking at procurement and had already made significant changes to avoid delays.

“Clearly we have got to get to a situation where we do procurement and we do project management properly in this authority,” he said.

“It is the biggest bugbear of my time and has been the thing that has let us down most. It is obviously not acceptable when children cannot go to school because of delays in delivering.

“Schools are working hard to ensure that doesn’t happen again. But it is a matter for individual schools if they open during the holidays or not.”

Councillor Jeanette Sunderland, the Liberal Democrat group leader, said that far too many school days were lost because of snow and training days. She said that the big six-week summer break also needed challenging.

Conservative Councillor Roger L’Amie, shadow portfolio holder for children’s services, said better organisation was needed to ensure that works did not overrun. “Procurement is not the strongest thing in local Government and there could be a lot done to get better value and better service,” he said.

Ian Murch, assistant secretary of Bradford’s National Teaching Union, which represents 3,000 district teachers, said that Coun Ruding was right to be concerned. He said there were big problems making sure builders finished their jobs in time.

“There has to be adequate penalties for building companies if schools fail to open on time because of building work,” he said. “It is important both for the education of children and childcare arrangements of families. But I can’t see how it is practicable to have schools open during holidays and the Council does not have statutory powers to make teachers work during the holidays.”

Other schools that remained closed in September included Allerton Primary, shut for more than a week because of the discovery of dry rot, Copthorne Primary closed for two days while classrooms were refurbished and Cottingley Primary which closed until September 8.