A listed building may not be demolished, extended, or altered without special permission from the local planning authority, which typically consults the relevant central government agency, particularly for significant alterations to the more notable listed buildings. In England and Wales, a national amenity society must be notified of any work to a listed building which involves any element of demolition.
Exemption from secular listed building control is provided for some buildings in current use for worship, but only in cases where the relevant religious organisation operates its own equivalent permissions procedure. Owners of listed buildings are, in some circumstances, compelled to repair and maintain them and can face criminal prosecution if they fail to do so or if they perform unauthorised alterations. When alterations are permitted, or when listed buildings are repaired or maintained, the owners are often required to use specific materials or techniques.
Although most sites appearing on the lists are buildings, other structures such as bridges, monuments, sculptures, war memorials, and even milestones and mileposts and The Beatles' Abbey Road pedestrian crossing are also listed. Ancient, military, and uninhabited structures, such as Stonehenge, are sometimes instead classified as scheduled monuments and protected by much older legislation, whilst cultural landscapes such as parks and gardens are currently "listed" on a non-statutory basis.
The basis of the current more comprehensive listing process was developed from the wartime system and was enacted by a provision in the Town and Country Planning Act 1947 covering England and Wales, and the Town and Country Planning (Scotland) Act 1947 covering Scotland. Listing was first introduced into Northern Ireland under the Planning (Northern Ireland) Order 1972. The listing process has since developed slightly differently in each part of the UK.
In the UK, the process of protecting the built historic environment (i.e. getting a heritage asset legally protected) is called ‘designation’. To complicate things, several different terms are used because the processes use separate legislation: buildings are ‘listed’; ancient monuments are ‘scheduled’, wrecks are ‘protected’, and battlefields, gardens and parks are ‘registered’. A heritage asset is a part of the historic environment that is valued because of its historic, archaeological, architectural or artistic interest.
Only some of these are judged to be important enough to have extra legal protection through designation. However, buildings that are not formally listed but still judged as being of heritage interest are still regarded as being a material consideration in the planning process.
As a very rough guide, listed buildings are structures considered of special architectural and historical importance whereas ancient monuments are of 'national importance' containing evidential values and can on many occasions also relate to below ground or unoccupied sites and buildings.