bassanclan

This sounds like the ideal time to learn how to lay bricks and build a brick wall which shouldn't last 50+ years

This sounds like a complicated way of going about putting up a fence. How do you plan to fix the fence to the concrete wall Would concrete posts and gravel boards not offer a similar solution?

Try before you buy

The flipper shown in @joe90 photo allows easy entry at the end, but that isn't possible in your situation, you're losing part of your showering area.

I would go to a showroom and try it out first as you may find it unnecessarily cramped getting in and out past the 200-300mm flap. You could just go the whole hog and make a wet room.

You are making your shower area too small. Either get a bifold, hinged or sliding door

https://www.ebay.co.uk/itm/282194371739 Is this the sort of thing you are thinking of?

I recently fitted both Velux and Keylite in a house. I would say Velux had the slight edge, but not a lit to choose between them. This was for a pitched roof, I havnt fitted the flat roof type.

Curved and flay are about the same price, curves often cheaper. The savings could be made by specifying smaller or a non opening or non electric or by buying something that someone has bought incorrectly https://www.ebay.co.uk/itm/153743896469

I think 58cm should be fine and the basin and shower screen won't have a sharp corners which will both be in your favour

I think the squares of ply are deceiving my eyes and making the gap look smaller than it really is. If everyone who has to use it is happy then it doesn't matter what anyone else thinks!

I can't quite tell if it's still too tight a quadrant shower might help. Put some boxes etc to simulate getting around things

You should wait 6 months after plastering and then use decorators caulk

I know this is slightly off topic, but have you looked into log gasification boilers? There was a very decent looking quarterly payment for using them. Ideal if you have the space and no access to mains gas.

Upvc residence 9 windows. They look like wood up to 2ft away

There are loads if top access 50mm traps, so not sure it can be that

I realise that different things can be done to try overcome the problem, it just seems bizarre that the 90mm waste is only on the slimline trays.

Why is it that if you want a slim stone resin shower tray (under 50mm) you can have a 90mm fast waste, but if you buy a "standard" deep stone tray say 80-100mm deep you can only get a 50mm waste? Is there any solution to prevent me paddling (deep) or letting the water almost overflow the tray (slimline)?

I don't know what quantity you have, but look at the price of seconds kingspan. E.g. seconds &co If you paid £100 for your material and seconds are £75 then the minimum you would want is £25 back or else you would have gone and bought the seconds in the first place.

Council large item disposal service

You could start by examining the building work you could do under permitted development

https://www.hotukdeals.com/deals/franke-renodanube-polished-stainless-steel-15-bowl-sink-tap-waste-kit-60-at-bqs-3406739 Saw this advert the other day

Terrible job You should give him the chance to put it right as it sounds like he let his workers/subbed do it. I would write a formal letter explaining everything you think is wrong. I'm not 100% that is even code 4 lead.

Difficultto tell if they are flag hinges or butt hinges. Flag can be adjusted https://www.windowware.co.uk/news/how-to-adjust-a-flag-hinge

Definitely tile first.