The most common type of floor construction being used in modern extensions/ dwellings in England and Wales is the solid floor. Fig 16.1 shows an uninsulated floor. In buildings exempt from Building Control (e.g. conservatories, porches and the like), this type of floor can still be used. It should also be used in attached garages where the floor will be subjected to heavy loads. There are other places where this type of construction may also be used in habitable areas. As I have mentioned before, extensions under 10 m2 to older properties are not subject to the same controls as larger extensions (see clause 0.3 of Approved Document L).