The near-doubling in size of a Farnham school for children with special educational needs can go ahead after an agreement was reached to monitor noise levels from its newly approved heat pumps.

The Abbey School in Menin Way is described as a “strong and vibrant special school with places for 100 children aged 11 to 16 years who have learning difficulties and additional needs”.

In February 2022, it had been granted permission to remodel its school buildings and play area – with work already underway. Once completed, the expansion will accommodate 170 SEND children.

However, complaints were raised against the location of its heating systems, with residents worried about noise, and it was agreed they would be moved from their original location on school’s sports hall roof to ground level – with added sound reduction measures put in place.

On December 20, Surrey County Council’s planning committee voted to move air source pumps, together with sound proofing measures, but said they would check back to ensure disturbances were kept to a minimum.

Officers told the meeting: “During the day it is accepted that against the background noise, noise produced by the pumps would not be entirely noticeable”.

However, they expressed concern that at night this could potentially lead to an adverse impact.

“Noise assessment considered the impact against the closest neighbouring dwelling and it was found that the potential noise impact was below the World Health Organisation standards and below the British standards.

“Environmental health officers noted that the noise from the air source heat pumps may be audible in external areas and audible in neighbouring properties.

“Inaudibility is not a planning requirement. However, it is accepted that the units as proposed could give rise to some noise.

“Therefore to further protect neighbours the screening would be amended to include sound absorbing materials.”

The amended plans were designed to address noise concerns although residents were also able to persuade the committee to go further and monitor the situation – making changes to sound proofing if necessary.

Air-source heat pumps, by their nature, cannot be fully enclosed.

Mark Finney, a resident said: “The new condition requiring absorptive panelling for the heat pumps is helpful, but not enough.”

He said it would require neighbours to “put up with an unpleasant, continuous, industrial hum”.

He added: “They can talk all they like about decibels, double glazing, and closed windows, but when time outside is blighted by that noise it needs to be properly dealt with.”