First floor escape window height

[Guest Steve Bai]

Bottom of the openable area is to be a minimum of 800mm and not more than 1100mm above the finished floor level.

What is the bottom of an openable area? Our site has equal split windows but the upper window is the egress window which is at 1500mm. The sill is at 1100 above finish floor level. Is this correct?

[Lyledunn]

I would say definitely not if it is for BC approval. It is probably reasonable to allow a standard frame but from your description the opening is 1500mm above ffl.