I believe the Party Wall Act states that notices are required if you intend to construct footings within 3 metres of the boundary line and to a depth deeper than that of a neighbouring structure. While we intend to build within 3 metres (1.6 metres to their back garden wall and 1.9 to their house), I’m not convinced that my footings will be deeper that the neighbours structure as the back of the house is actually an extension (approx 20 years old), hence why I do not believe I should serve a PW notice.
No access to the neighbours property will be required at all during the construction but my neighbour is insisting that I serve him a PW notice.
Firstly how do I know if my foundations will be deeper than the neighbours and secondly I am considering commencing the work without serving notice, since there are no penalties for not complying with the act.
The Act says within 3 meters of a neighbouring structure rather than the boundary line but both would seem to apply in your case.
If the neighbouring structure is a modern build and is built on traditional concrete strip foundation they are likely to be a metre or more deep. I assume that you are not excavating within 3 metres of any original part of the property that may be on shallower foundations?
You have no way of knowing the depth of your neighbour’s foundations so surveyors will generally make an assumption based on the age of the building and the ground conditions.
While it is true that there are no penalties for not complying with the Act but you run the risk of the Adjoining Owner applying for an injunction. There are also implications if your works do cause damage.