Retaining walls perform an important structural function.
Unlike a simple garden wall, they are designed to hold back soil or accommodate a difference in ground levels.
Because of this, retaining-wall projects can involve excavation, substantial foundations and construction close to neighbouring land.
These features can sometimes bring the Party Wall etc. Act 1996 into consideration.
Is every retaining wall covered by the Party Wall Act?
No.
A retaining wall built entirely within your own property does not automatically require a Party Wall Notice.
The important questions include:
- where the wall is positioned;
- whether it sits at the boundary;
- how deep the foundations are;
- how close excavation is to neighbouring structures; and
- whether existing party or boundary structures are being altered.
Retaining walls at the boundary
If the wall is to be constructed at the line of junction, Party Wall provisions concerning new walls at the boundary may need to be considered.
Our Section 1 Party Wall Notice guide explains the distinction between a wall built astride the boundary and one constructed wholly on the building owner’s land.
If an existing masonry garden wall is involved, our guide to Party Fence Walls may also be useful.
Deep foundations and excavation
Retaining walls can require substantial excavation.
If excavation is carried out near a neighbouring building and extends below the level of its foundations, a Section 6 notice may potentially be required.
Your drawings should clearly show the proposed depth and relationship with the neighbouring structure.
See our guide to Party Wall drawings for further information.
Existing boundary walls
Sometimes a new retaining wall replaces or supports an existing garden or boundary wall.
Before demolition starts, establish:
- who owns the existing wall;
- whether it is a party fence wall;
- whether it performs a structural function; and
- whether the works fall within the Act.
Simple Survey can assist
If you are proposing a retaining wall close to a neighbour or boundary, Simple Survey can review the drawings and advise whether Party Wall procedures apply.
Visit our Party Wall Surveyor service page for further advice.