I want to build the cavity wall of an extension up to the boundary of the neighbouring property. I can’t knock the fence between us down. Therefore, the blocks would not be coming straight of the middle of the foundation but the very side, what sort of foundation should I use, how would it look. Can I simply build the wall directly off the side of the foundation? Will I need a structural engineer to design the foundations or should an architect do that? any examples/ specs would be helpful.
Are you a tradesperson and able to answer this question?
Hi,
You will need to design an eccentrically loaded foundation. Your structural engineer will need to design this for you. They will be able to provide you with the correct detail showing the rebar required subject to the soil conditions and relationship to the boundary.
I hope this helps.
A wall can be built on the edge of a foundation, but a structural engineer will need to design this. An architect will be able to advise on the planning and building regulations for this situation.
If the neighbouring property is close to the party wall fence line (the boundary) you may need to consider whether a party wall agreement is required. The excavation for the foundation may be subject to the party wall act as may come close to the existing neighbouring foundations or may risk undermining them if substantially deeper. An Architect should be able to advise on simple scenarios of the Party Wall act.
It would need to be an eccentric loaded foundation. This would need mesh reinforcement at the top and bottom of the foundation and an RC35 concrete. Whether you need a structural engineer would depend on the Building Control Officer’s requirements.
Hi,
You can have a flush foundation in alignment with the outer skin of the external wall. It will need a structural engineer. If it’s on the boundary adjacent a neighbouring wall - you may need to look at the party wall act and issue a notice.
