St Stephen’s Trust has said that plans to build a new Royal Free hospital immunology ward are far from complete, and still pose a serious risk to the future of grade-I listed St Stephen’s Church, and Hampstead Hill School.

In a 30-page report by a structural engineer advising St Stephen’s Trust, it says the plans for the Pears building don’t properly address the problems brought about by section 106 requirements, and that the works still pose a serious risk to the site on which the church, and the school buildings are situated on.

Section 106 agreements can be part of a planning application, where it’s thought the plans could have a serious impact on the local area.

The report has been published by the trust in response to the Detailed Basement Construction Plan (DBCP) document from the developers, which aims to address section 106 concerns.

The proposal was given planning permission in April 2016, subject to meeting the section 106 criteria.

The trust believes that the piling walls that will separate the construction from the church site will not allow groundwater underneath to flow out, which will create a dam and cause the ground to slide.

There is also concern about the effect of pollution and noise on the schoolchildren as a result of the building work, and site traffic.

During work done by the trust at the Royal Free’s request earlier this year, they found that the church’s foundations were sound.

The concerns over the new building were raised at a public meeting about Camden Council’s planning department in December 2015.

The church hasn’t held regular worship for decades as a result of the damage done as a result of the work building the Royal Free hospital in the 1970s.

After the trust raised £6m, the church building was brought back into use for Hampstead Hill School in the late 1990s.

Chairman of St Stephen’s Trust, Michael Taylor said that if the proposals go ahead, it means that 400 children may not have a school to go to. He said: “For the school it means that when drilling with pneumatic drills commences, the school will have to close. The Church Hall will almost certainty become unsafe. The noise will make it impossible for the children to work.”

The 75-year-old also slammed the way that the Royal Free Charity had treated St Stephen’s Trust. “We’ve been treated like dirt during the whole process,” he said.

A Royal Free spokesperson said: “The Royal Free Charity has submitted its detailed basement construction plan to Camden Council. The charity is confident the DBCP meets the terms of the section 106 agreement and has demonstrated the construction work will not cause damage to any surrounding buildings.

“The plan will be assessed by two independent certified engineers who will recommend to Camden Council whether the section 106 agreement has been met. Camden Council will also have its own independent assessor and will make its decision based on this.

“We would like to thank the hundreds of people who have given us their views and helped us develop the plan during the 36 meetings we have held in the course of the last year, including the 18 meetings we have had with St Stephen’s Trust, Hampstead Hill School and Hampstead Green Neighbourhood Group.