Extension doorway from kitchen - is this needed?

[Leofric]

What makes an 1100mm high window harder to get out of with a 900mm high flat surface in front of it? And what regulation disallows such practise?

The regulations don't state everything that is disallowed ,there is no mention of not putting a dustbin outside a fire escape window but it is not a good idea.
p.s. Article in our local paper recently where tragically somebody burnt to death in a barn conversion that didn't have a proper fire escape window. The landlord who was also the builder had been notified of the requirements on fire safety but had ignored them. He has been found guilty of breaching fire safety regulations and is awaiting sentence but has been told he can expect to go to jail.