Ground source heat pump systems can involve boreholes extending many metres below ground.
Because of their depth, homeowners occasionally assume that Party Wall excavation notices must automatically be required.
The position is more nuanced.
Section 6 is not simply about depth
The Party Wall Act contains specific geometric tests governing excavation near neighbouring buildings.
Whether the legislation applies depends on the relationship between the proposed excavation and the neighbour’s foundations.
Depth alone does not automatically determine the answer.
Our Section 6 Party Wall Notice guide explains those tests.
Boreholes are different from conventional foundations
A narrow vertical borehole is physically different from excavating a wide trench alongside a building.
Its Party Wall implications should therefore be assessed according to the actual works rather than assuming that every deep hole is equivalent to conventional excavation.
What about horizontal ground loops?
Some ground source systems use horizontal trenches instead of deep boreholes.
Where these are relatively shallow and remote from neighbouring structures, Party Wall implications may be limited.
Closer or deeper excavations should be assessed individually.
Other regulations may apply
Ground source installations can involve matters outside the Party Wall Act, including:
- environmental requirements;
- drilling specifications;
- underground services;
- groundwater; and
- specialist installation standards.
The Party Wall Act should not be treated as the only consideration.
Neighbouring foundations still deserve thought
Where drilling equipment or excavation will operate immediately alongside a neighbouring structure, the designer should still consider stability, vibration and construction methodology.
Simple Survey can review unusual excavation
If your renewable-energy project involves boreholes or substantial trenches close to neighbouring structures, send us the proposed layout.
Simple Survey can assess whether Party Wall procedures need to form part of the installation programme.