It will greatly speed up the survey if you can ensure the assessor has easy access to all parts of the dwelling, windows, doors and the heating system such as the boilers and hot water cylinders.
If you have carried out any upgrades to the dwelling and want to include these in the survey, it is important that you can produce the adequate documentation and evidence to demonstrate the works carried out. These can be the declaration of works forms signed by the contractor, material certificates, delivery dockets, photographic evidence etc.
Evidence of the age of the property and especially the age of any extensions.
A recent electricity bill showing the Meter Point Reference Number (MPRN).