Would 1ooomm kitchen be ok and 1000mm bedroom allow for current fire regs?
The actual window size is irrelevant, its the 'openable' size with is important
"The window should have an unobstructed openable area that is at least 0.33m2 and at least 450mm high and 450mm wide (the route through the window may be at an angle rather than straight through). The bottom of the openable area should not be below 800mm nor more than 1100mm above the floor level."
The above applies to the bedroom only, and is not required for the kitchen one