Loft Conversion Windows - what are the options and requirements

First of all the windows for a loft conversion will serve three distinct purposes. The first is for ventilation either using the frame trickle vents or an opening sash. The second is for natural light which may seem obvious. The third and les obvious is for secondary means of escape in the event of fire and becoming trapped.

For venting the opening sash should be no less than 5% of the new loft conversion floor area. For natural light requirements of the loft conversion the percentage is up to 10% of the room floor area.

For secondary means of escape the requirements are a bit more complicated being:-

• All first and second floor windows for bedrooms must have opening lights/sashes large enough to escape through in the event of being trapped within a room by fire. To meet this requirement all such windows must have a minimum unobstructed openable area of at least 0.33M2 and not to be less than 450mm wide and 750mm high. Also the bottom of the openable area should not exceed 1100mm above the floor or be less than 800mm off the floor.