You should ensure that your insurance cover on your property covers you for building works and if not upgrade it so it does for the duration of the build. Also check that the builder has all his insurances in place prior to commencing on site. It is also good practice for the builder to send out a letter to your neighbours explaining what he is about to do, when he is starting the work and include his contact details. The client must be aware of any party wall obligations prior to commencement on site.