Party Wall Questions #3

Tuesday, 1st February 2011 | by: Peter Barry


Can a Building Owner cast a new mass concrete foundation above and alongside the projecting concrete foundation to an existing party wall and connect the two foundations with a dowel (known as ‘overpinning’) without serving notice?

This is another question that was raised at a recent FPWS North London forum meeting which I helped to organise. I would welcome the views of other surveyors. If you are a surveyor involved in party wall matters and would like to attend future meetings please email me at and I’ll keep you updated.


This would seem to one of those quirky details which occasionally crop up that should come within the scope of the Act but doesn’t.

The fact that there are at least 3 viable alternatives, raising the existing party wall under 2(2)(a), cutting back the projecting footings under 2(2)(g) or using a cantilevered slab suggests that the detail is a deliberate attempt to bypass the Act.

The only suggestion that has been put forward is Section 2(2)(f):

To cut in to the party structure for any purpose (which may be or include the purpose of inserting a damp proof course);

There is disagreement amongst surveyors over whether drilling for a dowel like the one shown above can be classed as cutting as detailed in this clause. In fact, the argument is superfluous in this scenario as Section 2(2)(f) only relates to Party Structures and following the definition in the Act a Party Structure does not include the foundation.

I will leave the obvious engineering concerns to others but if this detail was put forward to me in the capacity of adviser to the Adjoining Owner I would have to concede that no notice is required.

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