Plans to Build a Single Storey Rear Extension, The Party Wall Act and Right to Light

by: The Party Wall Surveyor


I recently moved into a terraced property. The neighbour on the right side introduced himself. We established a good relationship. A week later I informed him that I was going to build a single storey extension, he told me he had no problems with this and also told me of the various pitfalls to watch out for.  Three weeks later I invite the neighbour to look at the extension being build for his opinion. He looked around and also looked at the wall being built approximately 5 inches away from his fence and made no objection. I also commented that I hope the height will not affect their light. The neighbour’s response was ‘no its okay’.

However, the neighbor’s wife came to tell me that they are not happy with the height of the wall as it is blocking their light from the kitchen window. My response was that her kitchen window does not face the extension. Her response was the wall is affecting the light coming form the left as all she can see is the wall above the fence. 

The council was informed and drawings sent with planning application. The council sent a letter a month after the building work had started to inform me that the party wall act (may) apply, for me to pursue and not in their remit. The height is within the building control regulation under 4ft.


If your extension is 5 inches back from the boundary line then the only section of The Party Wall Act that could apply is the part that deals with adjacent excavations (Section 6). That would apply if you are excavating within 3 metres of any part of your neighbours’ structure (not their fence) and deeper than the base of the foundations to that structure.
Regarding the light issue, that is not something we cover on but a rear extension to a semi-detached or terraced property is unlikely to injure the light to a neighbour’s rear window sufficiently to give rise to a claim.