Eccentric Foundations are one of the most commonly used types of foundation designs in rear or side extensions and are commonly seen forming part of Party Wall Awards, Party Wall Notices and Party Wall Surveyor requests.
An eccentric foundation is a foundation whereby the wall sits on the outer edge of the foundation. The entirety of the foundation and the wall will therefore be wholly on the building owner’s land, meaning that they are not only getting a larger extension, but they are also reducing the impact of their proposed work on the adjoining owner’s property.
A typical foundation differs from this as the wall sits at the centre of the foundation. This type of foundation can either be placed astride the line of junction, thereby acting as a Party Wall. Alternatively, it can also be placed so that the wall is wholly on the building owner’s land, with the outer edge of the foundation projecting onto the adjoining owner’s land.
Eccentric foundations are used in a number of different situations during Party Wall works:
- When a building owner wants to build their proposed wall right up to the line of junction, thereby maximising the space of their proposed extension.
- When the adjoining owner already has their own extension in place, built up to the line of junction. Thereby, meaning a typical foundation design isn’t feasible.
- If the adjoining owner’s foundation projects into the building owner’s land, meaning a typical foundation is not possible.
- Where the adjoining owner doesn’t want any projections into their land, as they intend to undertake a similar extension in the future.
All of these situations will require the use of an eccentric foundation.
We have found that eccentric foundations are favored by Party Wall Surveyors for a number of reasons:
- They avoid projections into the adjoining owner’s property.
- They are well known and easily executed by contractors.
- They avoid future Party Wall issues (from the perspective of the adjoining owner’s property).
Below are a number of situations whereby eccentric foundations had to be used, along with a description as to why they were required.
Where the adjoining owner doesn’t want any projections into their land, as they intend to undertake a similar extension in the future.
If you are planning on undertaking an extension and you are unsure what foundations will need to be used, why not contact our experienced Party Wall Team now who will be happy to assist.