We are about to start building a new extension which includes a downstairs toilet which is off a utility room. The architect plans/ building control plans don't specify anything about the specification of the new window in the downstairs toilet. Looking at the Planning Portal website it states the following about installation of new windows.
- Width and Height - Either of these are not to be any less than 450mm
- Clear Openable Area - No less than 0.33m²
- Cill height - The bottom of the openable area should be no more than 1100mm above the floor area.