The following are the main criteria, which are used in deciding which buildings to include on the statutory list:

• Architectural interest: Buildings of importance because of their design, decoration and craftsmanship; also important examples of particular building types and techniques and buildings of significant plan forms;
• Historic interest: Illustrations of important aspects of the nation's social, economic, cultural or military history;
• Historic Association: Close historical association with nationally important people or events;
• Group value: especially where buildings comprise an important architectural or historic group or a fine example of planning e.g. squares, terraces or model villages.

The older a building is and the fewer the surviving examples of its kind, the more likely it is to have historic importance.  All buildings built before 1700 which survive in anything like their original condition are listed and most buildings built between 1700 and 1840 are listed.  Buildings erected after 1840 may be listed where they are the best examples of particular building types; only buildings of definite quality and character are listed.  Buildings less than 30 years old are normally listed only if they are of outstanding quality and under threat.  Buildings are not listed until they are at least 10 years old.