Retrofitting Historic Buildings - Westminster City Council

competent person’ scheme exists. Where you are uncertain about whether a particularmeasure is ‘permitted development’, you can always apply for a ‘certificate of lawfulness’.This may be important if the property is sold in the future.6. Undertake workEnsuring that any new systems work effectively, and that occupants (and future occupants)understand how to use them. There may also be changes necessary to the way in which aproperty is occupied, which must be clearly understood. For example, with many types ofinternal solid wall insulation it is vital not to pierce the waterproof membrane behind theinsulation which might happen easily when putting up shelves or hanging a picture.7. Monitor and undertake necessary maintenance12