Party Wall Awards on house near Hampstead Heath, North London

I was recently involved as Building Owner’s Surveyor in the refurbishment and extension project for a substantial five storey semi detached house near Hampstead Heath in North London.

The works included basement excavation for a swimming pool together with rear and side extension and internal alterations.  The detached adjoining property was within three metres and therefore required the service of Adjacent Excavation Notices on the neighbours.  Both adjoining properties were sub-divided into flats but fortunately they shared in the Freehold interest.  Party Structure and Adjacent Excavation Notices were served on the Adjoining Owners of the attached property.  Fortunately, all Owners within each adjoining properties chose to dissent but appointed the same differing Surveyor for themselves.  That at least meant that there was only one point of contact in negotiating for each adjoining property and alignment of comments which was most useful.  It also helped in coordinating access for the schedules of condition.

Drawings and Methodology in respect of the excavation works were provided and the Awards for the detached Adjoining Owners were fairly quickly agreed based on these with service showing the appropriate measures to retain support to the adjoining property throughout the works.

Naturally concerns in the property which shared the party wall were greater especially as the proposals included underpinning the party wall.  Their co-opting of a reviewing engineer was accepted due to the potential complicated issues involved and repercussions that could occur.  Detailed site assessment was provided together with the Design and Access Statement completed as part of the Planning Application.  I considered submissions from the reviewing engineers before forwarding to the project engineers and liaised with them regarding addressing the relevant issues.  There were a number of exchanges and when a site presence was established trial pits were carried out to check the existing foundations.  Surprisingly these revealed underpinning of adequate depth and further trial pits were carried out along the party wall to confirm this was continuous.  Details of the findings were provided and drawings updated to show that no underpinning was required although localised piling for temporary works was still required to be covered by the agreement.

With the significant reduction in areas of concern, minor outstanding queries were addressed and the final set of Awards served enabling the Building Owner to proceed with the works.

Peter Sharp, April 2026