A group of angry Swiss Cottage residents have launched a campaign group to oppose plans by a private school to build new classrooms

The Hall School, founded in 1889 for boys aged four to 13, is due to submit a planning bid for its senior school site in Crossfield Road in November.

It has been consulting with residents about its plans to pull down a 1970s building, build three new classrooms and dig a further four metres down below its existing basement to create a new sports hall and theatre.

The new building will be 4.5m higher than the existing one and other buildings on the site will also be reconfigured.

Anthony Kay, a Crossfield Road resident who has lived in the area for 40 years, has launched the Hall School Opposition Group to fight the “monster redevelopment”.

He said: “There will be huge construction works knocking down a perfectly good building. Lorries will have to travel down Eton Avenue. The school is always expanding its activities, always trying to grab more. It is being run too much like a business and impinging on the good nature of its neighbours.”

A report from local authorities body London Councils last month found that by 2021/22 London will need 63,000 more primary school places and 47,000 at secondary level.

But Mr Kay doesn’t want the Hall School to take on more pupils and fears it will do once it has increased its capacity.

“This is a highly residential area. Other schools aren’t nearly as big. The school already has 450 pupils and is very dominant in the area.”

Mr Kay was part of the campaign that in 2006 successfully fought the school’s plan to build a basement swimming pool. He said more than 30 residents from Crossfield Road, Eton Avenue and surrounding streets have already registered their support for this new campaign.

David Reed, who lives in Eton Avenue, added his name to Mr Kay’s cause. He said: “Our main objection is the plan to dig an even bigger basement in an area where there are no others, so this would set a precedent.

“If they were accommodating more local children then it might be worth it. It is a very prestigious school – not for ordinary people from the area. It brings in a lot of people in their big fat cars from outside the neighbourhood.”

Hall School headmaster Chris Godwin said: “Rather than continuing with piecemeal repairs and upgrades as we have done for over 100 years, our vision is to comprehensively refurbish the senior school and build modern teaching facilities fit for the 21st century.”

Mr Godwin said the school would not be increasing pupil numbers. “These plans are simply about providing more ‘room to breathe’ for our boys; allowing them to develop more broadly, with improved classroom and play space.”