On 24/04/2021 12:48, GB wrote:

I was recently helping my son in law get his flat ready to sell, and I
noticed that the Critall metal windows have unusual hinges, like in the
photo.Â* These are similar to parliament hinges.

https://www.deltaglazing.co.uk/wp-co...ow-repairs.jpg


The effect is that, with the window open there's a gap at the hinge side
that's wide enough to get your arm through for cleaning the outside of
the window.

That's such a simple idea, and so easy to implement that I'm surprised
it's not more commonplace.
just an early 1950's easy clean hinge so you can get your hand
through,,,,no big deal...but quality