When a wall is on the centreline of a foundation then the foundation bearing pressure is uniform. However, if the load is applied eccentrically (such as happens when a building is being built right up to a boundary), then the bearing pressure is not uniform and this can theoretically result in high bearing pressures being generated beneath the edges of the foundation.

If this situation is likely to arises, then the local authority often want justification calculations to be provided. There are several ways of doing this. The traditional design method involves assuming a rigid foundation and a variable pressure distribution beneath the base. This results in very large and uneconomic foundations. We take a more pragmatic approach which results in a much more economic foundation design.

We need the following information to design an eccentricly loaded foundation:

architectural layouts and elevations or sketch drawings with dimensions of the property / extension

the distance between the outside of the wall and the boundary (if it is not actually on the boundary)

Design information

All designs are carried out in accordance with BS 8110 (The structural use of concrete) and BS 8004:1986 (The code of practice for foundations).

The calculations provided will be suitable for Building Regulation approval.

You should satisfy yourself that the excavation for the foundation will not undermine any adjacent foundations or neighbouring ground.

Excavations may fall under the Party Wall Act Please seek specialist advice. click for party wall act information