BS 644 specifies requirements for materials (including timber preservation), profile design, workmanship, glazing, construction, safety, security, weather tightness performance, and operation and strength performance of factory assembled timber windows of the following types:
a) hinged: side hung, top hung and bottom hung;
b) projecting side hung (open out or reversible);
c) projecting top hung (open out or reversible);
d) pivoted: horizontal and vertical (hung centrally or off-centre, including reversible);
e) sliding: horizontal and vertical;
f) tilt and turn;
g) fixed light; and
h) direct glazed.
BS 644 does not apply to windows supplied as kits for site assembly.
The timber windows covered by BS 644 may be treated with either opaque or non-opaque finishes. Some glazing and finishing operations may be carried out on site.