Party Wall Surveys, Awards and Notices.
If you are soon to have an extension, or in the case of terraced and semi-detached houses have a loft conversion or other internal modification such as removing a chimney breast, you need to be sure the work does not come under The Party Wall etc. Act 1996.
In the majority of cases it will.
There then becomes a correct proceedure to follow and usually a surveyor to appoint who will need to make an inspection; all of which must take place before any work is started - and in good time.
The consequences for not calling in the appropriate professional and being properly advised could leave you open to a financial claim from your neighbour(s) that you might otherwise avoid.
A proper Party Wall Survey or Award may also help toward ensuring that your builder undertakes the work properly and proceeds with due care and diligence.