Nearly two years after an earlier application was rejected by Perth and Kinross Council, Persimmon Homes have submitted plans to create 91 homes at the former school.

However, an ecological survey discovered seven roosts within the school which are used by soprano pipistrelle bats, as well as an eighth roost in a house adjacent to the school.

The school buildings were found to be dilapidated with abundant features through which the bats could use to enter them.

A report by environmental consultants Acorna Ecology stated that, before any area of the buildings within 30m of each bat roost can be demolished, Persimmon Homes have to apply to Scottish Natural Heritage to allow for legal disturbance and destruction of the roosts.

The report said: “It has been concluded that the roosting bats are an ecological restraint for the proposed demolition and redevelopment of the site.

“The bat protection plan will detail the proposed methodology to minimise roost disturbance and will detail what is required for successful roost destruction, while minimising the potential for harm to the bats.”

An April 2014 survey had found no active bat roosts within the school, although there was an active bat roost within the adjacent housing development to the west of the site.

Due to delays in the proposed demolition, the buildings were re-surveyed in September 2015 and the seven bat roosts were discovered.

Bats Conservation Trust director of fundraising Dr Joe Nunez-Mino said: “The sharp decline in bat numbers in the last century means that all of our bats and their roosts are protected by law. Wildlife should be an integral part of any development/planning process.”

Persimmon’s latest application proposes to retain part of the Edwardian building that fronts the High Street, which was to be destroyed in the earlier application.

Managing director at Persimmon Homes North Scotland Iain Innes said: “Having identified bat activity on the site, we appointed specialist ecological consultants.

“They will apply for a Scottish Natural Heritage licence before we start any work on the development.”