Very little has changed and the amendments to the principles on which buildings are selected for listing are fairly light touch. Most additions to the guidance are more by way of background changes, for instance, explaining how Certificates of Immunity from Listing and Building Preservation Notices relate to the listing process. Some subtle changes have been made to the principles of selection themselves and perhaps suggest a more inclusive approach to listing, under which more new and unique buildings can be protected.

• 'Architectural Interest': a building must be of importance in its architectural design, decoration or craftsmanship; special interest may also apply to nationally important examples of particular building types and techniques (e.g. buildings displaying technological innovation or virtuosity) and significant plan forms. The 2018 principles extend 'Architectural Interest' to include engineering and technological interest. For more recent buildings in particular, the functioning of the building will also be a consideration. Artistic distinction can also be a factor relevant to the architectural interest of buildings and the objects and structures fixed to them.
• Historic Interest': a building must illustrate important aspects of the nation’s social, economic, cultural, or military history and/or have close historical associations with nationally important people. The 2018 principles extend 'Historic Interest' to include not just people, but groups or events; and the building itself in its current form must have a strong connection with a valued aspect of history. Note that the 2010 principles stated that there should normally be "some quality of interest in the physical fabric of the building itself". This wording is removed by the 2018 principles. In our view this does not necessarily mean that buildings with no architectural interest whatsoever will be listed, merely that it perhaps helps separate the concepts of architectural or historic interest by removing the consideration of aesthetic qualities when assessing historic interest. 

• 'Group value': the extent to which the exterior of the building contributes to the architectural or historic interest of any group of buildings of which it forms part.
• 'Fixtures and structures in the curtilage': the desirability of preserving any feature of the building consisting of a man-made object or structure fixed to the building or forming part of the land and comprised within the curtilage of the building.
• The character or appearance of conservation areas'. This is added by the 2018 principles. For planning applications within a conservation area, decision makers must "pay special attention to the desirability of preserving or enhancing the character or appearance of that area". It is unclear whether this latest consideration intends to invite the listing of more buildings in conservation areas simply as a further means of protecting the area’s character or appearance.

• Age and rarity': the older a building is, and the fewer the surviving examples of its kind, the more likely it is to have special interest. Previously more recent buildings were only listed if they were "of outstanding quality and under threat". The 2018 principles take a more inclusive approach towards newer buildings, making it appropriate to list them simply when "they demonstrate outstanding quality". The principle that most buildings built before 1840 will be listed is also shifted to 1850. 
• Aesthetic merits': the appearance of a building, both its intrinsic architectural merit and any group value. 
• 'Selectivity': a building may be listed primarily because it represents a particular historical type in order to ensure that examples of such a type are preserved.
• 'National interest': the most significant or distinctive regional buildings will normally be listed because together they illustrate a nationally important but local tradition. 

The SoS’s stated policy is now to provide as much clarity as possible about where the special interest of buildings lies when listing them or revising an existing list entry. This will be helpful going forward. Much litigation in recent years has concerned what constitutes a building's curtilage, or what constitutes a fixture or a fitting. Although it is sometimes impractical to specify what is and is not listed at a particular property, increasing the level of detail for such matters can avoid confusion and the need for enforcement. It is worth noting that that Historic England produce Selection Guides for specific building types to demonstrate what features are considered significant when assessing buildings of a particular type from different periods, regions, or styles. However, the general principles of selection take precedence over the Selection Guides, which are published as supplementary information.

Maples Teesdale advise on all aspects of Town and Country Planning, including heritage matters. Should you need advice on heritage matters please contact Partner John Bosworth.