Since
the issue of Joint Practice Note No. 2 in February 2002, non-structural prefabricated
external walls in domestic building has been exempted from Gross Floor Area (GFA)
and Site Coverage calculations. The criteria for such exemption includes non-loading
bearing, satisfy curtain wall design requirement, maximum thickness of 300mm.
The cumulative GFA exemption of all green features is capped by 8% of the total
permitted GFA for the development. Developers, in the light of such GFA exemption,
are more willing to join the contractors in studying alterative pre-cast construction
proposal.