Building projects do not always proceed exactly as originally drawn.
Ground conditions, Building Control requirements or contractor recommendations can sometimes result in the foundation design changing after Party Wall Notices have already been served.
This needs to be handled carefully.
Why does a foundation change matter?
A Party Wall Notice should accurately describe the notifiable works.
Changing from a relatively shallow foundation to a deeper system could affect:
- excavation depth;
- distance calculations;
- the structural methodology;
- whether Section 6 applies; or
- whether additional Party Wall issues arise.
Common design changes
Examples include changing from:
- strip foundations to deeper trench fill;
- conventional foundations to piles;
- shallow foundations to a raft;
- unreinforced to reinforced construction; or
- the original foundation position to a revised layout.
Do not assume the original notice still covers everything
A material change to the notifiable works should be reviewed by your Party Wall surveyor.
In some cases further notice or additional Party Wall documentation may be appropriate.
Simple Survey’s guide, Works Started But Now You Need a New Party Wall Notice, explains why design changes need to be considered carefully.
Special foundations
If reinforcement is introduced near or beneath neighbouring land, the special-foundations provisions may also become relevant.
See our dedicated guide to Special Foundations under the Party Wall Act.
Keep your surveyor informed
The simplest approach is to send revised structural drawings to your Party Wall surveyor before the changed foundations are constructed.
This allows the position to be reviewed while options remain open.
Simple Survey can help
If your engineer or contractor has changed the foundation design after Party Wall Notices were served, contact Simple Survey promptly.
Visit our Party Wall Surveyor page and send us the revised drawings so we can advise on the next steps.