A listed building is a building, object or structure that has been judged to be of national importance by virtue of its special architectural or historic interest.

Listing, sometimes also referred to as 'designation', is the act of identifying nationally important heritage sites and affording them special protection through the planning system. Listing can refer to the listing of buildings, scheduled ancient monuments, the register of parks and gardens, battlefields and wreck sites.

Buildings can be listed as:

• Grade I - exceptional interest (2% of all listed buildings)
• Grade II* - more than special interest (5.5% of all listed buildings)
• Grade II - special interest (92% of all listed buildings; most likely grade of listing for a home owner)

It is a popular belief that only the primary facade or exterior envelope of a building is listed, however, this is incorrect in all but a handful of cases. If a something is listed, the entirety of the building, object or structure is listed, including the interior, unless parts of it are specifically excluded in the list description.

Listing can also cover:

• Other attached structures or features
• Later extensions or additions
• Buildings, objects or structures within the curtilage of the building

The older a building, the more likely it is to be listed. All buildings built before 1700 which survive in anything like their original condition are listed, the same follows for those built between 1700 and 1840. After 1840 a higher level of selectivity is employed with particularly careful decisions made for buildings post 1945. Usually a building must be over 30 years old to be eligible for listing.

Anyone can nominate a building to Historic England to be listed, though, due to the amount of buildings to be reviewed the process can take a considerable amount of time. Generally a building will only be considered for listing if under serious threat of demolition or major alteration, or if it is a building that falls into Historic England's strategic listing priorities.

Historic England has produced a series of listing selection guides to aid their recommendation to the Secretary of State for Culture, Media and Sport as to whether or not a building has the commensurate special architectural or historic interest to be listed. Each of the 44 selection guides (of which twenty relate to different building types) gives a broad overview before setting out subject-specific selection principles.

The following list of examples should give you an idea of when listed building consent is required. However, this list is not exhaustive and you should always check with the conservation officer at your local planning authority if you are uncertain.

Demolition - demolition of any part of a listed building, whether or not it is partial or total demolition, will require an application for listed building consent. The same follows for objects or structures within the curtilage of listed buildings.

Extensions and internal and external alterations - should the proposed works change the character or appearance of the external facade, the internal configuration (sometimes refered to as plan form) or any historic features (staircases, fireplaces, doors and windows, paintwork or decorative mouldings and joinery) then listed building consent will be required. The same follows for objects or structures within the curtilage of listed buildings.

Repairs - consent is not normally required for repairs to listed buildings provided that the work is minor and identical in every respect of design, technique and materials. However, if the work constitutes a major scheme of repair, or the works will change the character or appearance of the building then consent may be required. If in doubt ask you local planning authority.

For a more in depth explanation of the planning legislation and policy which protect listed buildings visit Heritage protection legislation and policy explained