Bicester Building
Always difficult without seeing it in context of its surroundings, however if it overlooks the airfield it 'may' be an early airfield Battle HQ designed to be the point from which the Airfield defences would be controlled if it came under a direct assault. We had something similar at RAF Kenley; built in brick during the expansion period. Actual wartime ones were concrete with observation slits but early ones were a basic OP that could coordinate whatever airfield defences were available.No doubt these were in consideration of parachute landings or even enemy troop machines and i suspect in their day had a direct landline link to the local ops/sector centre. At Kenley the works and bricks removed it at the same time as they destroyed the historic Sector ops room (looks like a bungalow) thereby completing the failed Luftwaffe's attemps to do the same. !!!!