From January 2005, domestic electrical installations
will come within the scope of the Building Regulations. From then on, all new domestic electrical installations, together with specific alterations and additions to current installations, will have to be inspected and comply with strict electrical safety performance standards. The standards will cover the design, installation, inspection and testing of domestic electrical work and the provision of information.
When the time comes to sell your property, your purchaser's surveyors will ask for evidence that notifiable domestic electrical work, installed after January 2005 complies with the new Building Regulations. There will be two ways to prove compliance:

A certificate showing that the work has been done by a competent installer
who is registered under one of five Electrical Self-Certification schemes (this is the preferred route) or

A completion certificate
from the local authority saying that the installation has approval under the Building Regulations. This however, is dependent on the owner who has ordered the work, on providing relevant electrical test certificates on completion of the installation, from a competent person.