The opening of the new UCL Academy school building in Swiss Cottage will be delayed by seven weeks because of the liquidation of a building company working on the site.

The new school building in Adelaide Road, Swiss Cottage, had been on track to be completed by the start of the new school year in September, but this has been delayed by the collapse of sub-contractor Airedale Electrical.

The delay means the council and UCL are seeking alternative premises for 350 students due to start at the academy in September.

It is understood the pupils will use classrooms at the old site of Swiss Cottage Specialist SEN School in Brondesbury Park, which was in use until last term, for seven weeks between the start of the school year and half term.

Lead contractor on the school build, BAM, will absorb any costs of bringing classrooms back into use.

Pupils who attend the Swiss Cottage Specialist SEN School, which is co-located on the site of UCL Academy, will have access to their new building from the start of the school year.

Professor Michael Worton, vice provost of University College London (UCL) said: “We were deeply disappointed to hear the news that the new building will not be ready for September 2012. We are working with Camden and BAM to ensure that the very best temporary accommodation is made available and that any disruption is minimised.”

He added: “Staff are committed to ensuring that our students’ learning experience is enhanced, rather than hampered, by the unfortunate delay.”

The academy is sponsored by University College London, one of the country’s top universities, and will specialise in maths and science.

All pupils taking A-levels will also be required to pick one arts or humanities subject to help create a balanced portfolio.

In May this year the academy had received 1,085 applications for 180 places in the first Year 7 entry form this September – just over six applications for every place.

Cllr Angela Mason, cabinet member for children, said she had been assured the buildings would be completed on time, most recently in a letter on June 10.

She said: “Our overriding interest is the welfare and education of the children at both schools and the council has already written to UCL and Swiss Cottage to offer our assistance in finding the best possible solution for the young people affected.”

Sean Bradley, director of BAM, said: “We are committed to overcoming the problems caused by the collapse of our sub-contractor.

‘‘We will use our array of professional staff and resources in partnership with Camden and UCL to solve the challenge we face.”