Description

BS 644 specifies requirements for the design, construction and performance of fully finished and glazed factory-assembled timber windows of various types.

It applies to windows that have been treated with either opaque, non-opaque finishes, or that are designed to support an externally fixed covering of another material, and that have been factory-glazed. It does not apply to windows supplied as kits for site assembly.

BS 644 applies to windows fabricated into frames in a factory, to be installed vertically (±15°) into the external face of buildings, as single or multi-light units, in coupled assemblies when appropriate, of the following types:
a) Hinged: side-hung (open in or out), top-hung (open out), bottom hung (open in), tilt and turn or turn before tilt.
b) Projecting: side-hung (open in or open out) and top-hung (open out).
c) Pivoted: horizontal and vertical (hung centrally or off-centre).
d) Sliding: horizontal and vertical.
e) Side-hung and top-hung (open out) fully reversible.
f) Fixed light.
g) Direct glazed frames.

BS 644 should be used for assemblies in which any frame member is not longer than 3 m. It does not apply to curtain walls that span across horizontal structural members of floors but does apply to windows within a curtain walling system. It is also applicable to assemblies up to the factory gate.