Party Wall Questions #9

Wednesday, 31st August 2011 | by: Peter Barry


If a Building Owner appoints a surveyor on behalf of an Adjoining Owner in accordance with Section 10(4) can that surveyor give consent for special foundations on behalf of the Adjoining Owner (or can they if it is in the best interests of both buildings)?

Where an Adjoining Owner will not give consent for Special Foundations can they also object to the mass concrete underpinning projecting beyond the face of the party wall; as shown below?


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.


Part one of the question is straightforward. Section 7(4) of the Act states that

Nothing … shall authorise the building owner to place special foundations on land of an adjoining owner without his previous consent in writing.

Therefore the only situation where an Adjoining Owner’s surveyor could consent to special foundations is where he is specifically authorised to do so.

It’s easy to see why an Adjoining Owner would be concerned about the detail shown above – it prevents him from utilising the full width of his basement should he decide to convert in the future.

Where an Adjoining Owner refuses to consent to special foundations the only alternative is mass concrete.

Although Section 2(2)(a) gives a Building Owner the right to ‘to underpin, thicken or raise a party structure…’ it doesn’t specifically state that he can use underpinning that is thicker than the wall above (although it would have to be to be effective) nor does it say on which side the thickening must be.

A parallel can be drawn to Section 1(6) of the Act which relates to new walls on or at the Line of Junction and says that a Building Owner can place below the level of the land of the adjoining owner such projecting footings and foundations as are necessary for the construction of the wall.

It is generally accepted that the surveyors (with engineering advice is required) should decide what is necessary. I believe that it should also be for the surveyors to decide whether it is necessary to project underpinning and to what extent.

A reasonable compromise would be for the wall to be extended down in its current thickness (in brick or concrete) and for a wider foundation to be placed below the floor level of the basement. Assuming that the properties are at the same level the Adjoining Owner would not then be of space when they come to convert their basement in the future.

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