Providing the floor area of the property will result in a more accurate rebuilding cost (even if it is an estimate). If floor area is not available, use the number of room and/or number of bedrooms option. Providing both the number of rooms and bedrooms will help in estimating the floor area.

The floor area for flats should represent the gross internal floor area measured in square metres. The gross internal area of the flats is defined as the floor area of the flat measured to the internal face of the perimeter walls of the individual flat. This can be calculated by multiplying the total length of the flat by the total width (unless the flat is not a rectangle on plan when an appropriate adjustment should be made).

Exclude common areas from your measurements (there is an allowance for this in the calculator).

Exclude balconies extending beyond the external wall face.

The value entered must be in square metres. If you have the area in square feet then divide by 10.76 to give the area in square metres.