Skylights commonly suffer from water leakage and condensation around the frame and curb or tunnel. For operable skylights, ensure that hardware is working and all seals are in good order. Keep rain out by repairing exterior seals and flashings. Curbs and interior tunnels around the skylight must be well insulated and air sealed to reduce condensation. Reduce summer overheating with light-reflective glazing and blinds.

Do not open a skylight (or upper storey window) in hot weather if the house air temperature is cooler than the outside air. Opening the skylight draws hot air into the house, negating the effectiveness of air conditioning or natural cooling.