Providing the number of storeys is optional but helps in calculating a more accurate rebuilding cost.
Bungalows are single storey houses but Chalet bungalows are two storey houses.
'Garden basements' (ie a lowest floor level built within retaining walls which are not a part of the external walls of the house) are treated as an additional floor. Eg a house with a garden basement and two floors above is a three storey house.
If the house has had a loft conversion, it should be included as a floor.
The options vary depending on the type of building. There are only models available for four storey houses built between 1720 and 1839.
If you do not know the number of storeys for a house the calculator will make an assumption from 2, 3 or 4 storeys: Unknown implies that this property is not a bungalow.
U for unknown when used for flats assumes a low or medium rise block ie 2, 3 or 4 storeys. High rise blocks are not covered.
The number of storeys for flats is the height of the block, not the individual flat or the floor that the flat is on. The models only apply to flats built on one floor.
Maisonette can mean a flat on two floors (ie with internal stairs) or a flat in a two storey block that has its own entrance at street level. Maisonettes from the first definition are not supported while those from the second definition are purpose built flats and are covered by the BCIS models.