EXTENSION MASTERCLASS
Very few gardens make ideal building plots. Common impediments such as trees, drain runs and boundary fences can normally be accommodated at the design stage, but where gardens have a distinct slope there are important extra considerations that need to be taken into account.
The Building Research Establishment (BRE) have identified unstable sloping ground as a major cause of progressive movement in buildings. So to avoid any future risk of cracks appearing in extension walls, deeper stepped foundations will likely be needed.
Building Regulations provide clear guidance on how these can be constructed (Approved Document A). They also stipulate that solid floor slabs should not be used where sloping ground requires more than 600mm depth of infill at any point, in which case floors should be of suspended construction, either concrete or timber. Where extensions on sloping sites are constructed with a stepped configuration, the Building Regs also stress the
