installation tolerances

Hello all! So, bought a house in 2021 and 6 months prior the previous owners had all the front windows replaced. All 4 sets have side hung, outwards openings. In the middle of the hinge side opening (vertical), there is a gap large enough to fit a piece of card through. A trades person who is...

I've had a set of bi-folds installed which required a 5m RSj to be installed too. The RSJ has been installed onto two pieces of cut steel and not padstones due to my exposed brick outer wall. The RSJ over it's length has in excess of 10mm difference in install height and the RSJ is not level...