Table 1.

Ranking scheme of building damage categories (modified after Cooper, 2006).

Class
0	No damages.
1	Hairline cracking not visible from outside. Fine cracks, generally restricted to internal wall finishes: rarely visible in external brickwork. Typical crack widths up to 1 mm. Generally not visible from outside.
2	Cracks not necessarily visible externally, some external repointing may be required. Doors and windows may stick slightly. Typical crack widths up to 5 mm. Difficult to record from outside.
3	Cracks that can be patched by a builder. Repointing of external brickwork and possibly a small amount of brickwork to be replaced. Doors and windows sticking, slight tilt to walls, service pipes may fracture. Typical crack widths are 5–15 mm, or several of say 3 mm. Visible from outside.
4	Extensive damage that requires breaking-out and replacing sections of walls, especially over doors and windows. Windows and door frames distorted, floors sloping noticeably; some loss of bearing in beams, distortion of structure. Service pipes disrupted. Typical crack widths are 15–25 mm, but also depends on number of cracks. Noticeable from outside.
5	Structural damage, which requires a major repair job, involving partial or complete rebuilding. Beams lose bearing capacity, walls lean badly and require shoring. Windows broken with distortion. Danger of instability. Typical crack widths are >25 mm, but depend on the number of cracks. Very obvious from outside.
6	Partial collapse. Very obvious from outside.
7	Total collapse. Very obvious from outside.