A top Highgate private school has been given the green light to build a modern glass extension despite concerns it will blemish the village’s conservation area.

Haringey councillors voted to allow Channing School to build the 300 seat performing arts centre behind the historic Bank wall, next to a small row of listed Georgian houses.

The controversial move has sparked calls for Highgate’s conservation area to be strengthened to prevent future developments harming the village.

Highgate Cllr Bob Hare told Haringey Council’s planning meeting on Monday night (April 16) it was with a “heavy heart” he was urging the committee to vote against the plans.

He said: “Schools wanting to expand come in with such a feeling of goodwill from everybody, it is remarkable it has attracted so much criticism.

“Our opposition isn’t because we don’t want the school to ever expand, we want to get better designs.”

Channing is set to demolish their existing sports hall and construct a new glass building in an historic garden where pupils will take performing arts and sports lessons.

Speaking after the decision, Cllr Hare said he was struck by the flurry of letters he had received from residents objecting to the plans.

“This case highlights the need to put more meat on the bones of the conservation area statement,” he said.

“If it was tighter, it might have been easier to say how important the garden Channing is building on is in terms of the conservation area and stop applications like this.”

Greg Cooper, a planning consultant speaking against the plans, said: “This part of the conservation area is undeniably characterised today as a cascade of historic gardens which provide the visual setting for Cromwell House (a 17th century house), all the listed houses, and Founder’s Hall (a Channing School building).

“This is the character the law requires you to pay special attention to preserving.”

Headteacher Barbara Elliott insisted the new building is desperately needed to make the school’s facilities fit for purpose and said the school had re-shaped the design to accommodate concerns.

She said: “It has been a lot of hard work and we have listened very carefully to everybody’s concerns and we are very responsive to the concerns of all the local community groups.

“But this is the future of our children and community, and that includes Channing girls present and future generations.”