One appliance and crew from Beaconsfield, two from High Wycombe, one from Gerrards Cross and one from Aylesbury attended, along with two officers.
A single-storey commercial building was alight when they arrived. The incident was generating multiple calls to Thames Valley Fire Control Service.
The firefighters used two sets of breathing apparatus and one hose reel jet.
The building was around 20 per cent damaged by fire.
