Our neighbours are halfway through building their extension. Reluctantly, because we like them, we gave permission for some of the work to be done from our side in exchange for an agreement that they will pay for new garden trellis, plants and so on. They have signed an agreement which we drew up between us to pay for this and any other damage which may be caused.
Now we have been told by a surveyor that we need to think to the future and have a more complicated award drawn up, in order to avoid complications if we were to sell our house. The wall of their extension is several inches inside the party divide but the foundations extend into our garden. We were told that if we or a future owner of our property wanted to build an extension too, with our wall a few inches inside our land, then the new wall would be on part of their foundations. Also it would have to be closed off at the top, joining their wall. To do this might be an issue unless there was already an award drawn up.
We feel we need a second opinion on this. Secondly, the surveyor (who is the person who did the surveying when we bought the house several years ago) wants to charge £500 which – whoever ends up paying – is a problem.
If your neighbours served the correct notice they would have a right of access to your property under The Party Wall Act subject to them making good any damage caused. Any agreement beyond that – such as the new trellis – was outside of the Act.
The time for preparing an award has probably passed if your neighbours are already halfway through their building work. From your description of the works it is only the excavation work and the projecting foundations that would come under the scope of the Act. If that part of the work is complete it will not be possible to have an award drawn up. The Act does not allow for retrospective awards.
Any extension to your own property in the future will be dealt with independently if it comes within the scope of the Act with no reference to any previous awards. If there are foundations projecting on to your side of the boundary you will have the right to cut them off – subject to serving the necessary notice (but, as I say below, it would be better if they did not project). You say that the neighbour’s wall is several inches to their side of the boundary; if this is the case then the foundation is probably not projecting very far over the boundary, if at all. A typical strip foundation which is centrally loaded is 18 inches wide. The new wall will be between 10 & 11 inches wide so the projection on either side will be around 4 inches. Foundations can be eccentrically loaded i.e. built with the wall to one side and that would be a better option than allowing them to project on to your land.
£500 is actually a bit below the current average rate for a surveyor appointed by an adjoining owner for this type of project in London although if the surveyor that you mentioned is suggesting you have an award drawn up to cover work which is already complete he is probably not very experienced in party wall matters.