bassanclan

I presume it is cold mains pressure? Check under the basin in case someone has turned an isolation valve accidentally whilst cleaning etc

Personally I would build an "over engineered" timber platform with a 18mm ply top upon which you sit any stone resin tray. Or if on a masonry floor make it out of dense blocks. I have used a couple of the proper manufacturers leg systems before and they never feel as study.

Junior hacksaw will do the job nicely

I opted to join the British Gas zero standing charge offer too, it looks like if you didn't opt in you ended up on the 22p a day tariff as shown

You need to have a look if they do a direct air feed kit like this: https://www.harworthheating.co.uk/product/ap-duns-107/

The only way you are going to be happy is to get into a conversation with a senior executive and get them to buy the house back. From their point of view they could end up throwing thousands of pounds at the house and it still not be up to scratch. They would surely be able to buy it back, unburned themselves from any warranty etc and them sell it on.

Is that wall really 60mm out of plumb over about 1200mm!?

It looks like a Herald Hunter https://www.stovesareus.co.uk/hunter-herald-8-woodburning-stove.html They do a number of sizes etc so a quick measure up may help

The fact that it has a round hole in makes me think it's a sliver of brick, but it's not compressible, so is ideal to pack up one ens of a stone ledge to get it level

I would put ct1 between the frame and the wall/ tray, and follow 21ABCD

If you took time off to meet their clown then bill them... https://www.moneysavingexpert.com/reclaim/delivery-rights/

You could consider the total bill. Eg original chippies quote for whole job minus the new chippie cost. If that amount is more than £800 then you are quids in, if not you should make an appropriate deduction.

https://www.cityplumbing.co.uk/C-Tec-CT1-Grey-Sealant+Construction-Adhesive-290ml/p/991057?uiel=Desktop Grey ct1. Also stocked in a lot of TP or plenty of places online

You can use CT1 instead of silicone. It is very tricky and takes a lot of time to make it look good, but it will stand the test of time, but white discolours and I've had similar with clear before.

4/5 a day, I pay £130 a day cash, labour only

Before you use the window as your starting point you really should take some measurements around the room and see if t will work. Also are you going to fully tile all walls or have some half height? I always do some half height and then full walls around baths/showers as it can be a bit oppressive as fully tiled (and it saves tiles), but that's personal preference.

I always start marking out from the windowsill height. If you have any sense any boxing in etc is set at the same height as you windowsill and follows round, so a whole tile(s) goes below the windowsill, then a cut to the floor. With staggered vertical joints there would be a half tile. Spend a bit of time laying it right out now and it will save you a lot of messing about later

There are thin stone resin ones available I'm sure

I bought a pearlstone tray (ebay) as it was the only one available in the 1000x1000 size I wanted at the time. I think there would be nothing wrong with it if fitted to a solid base eg concrete. I had in on legs and it bowed and eventually cracked - lasted about 15 months! Personally I would go for stone resin, which is what has replaced it- a bit more money, but worth it in the long run. If you need it raised off the floor, don't bother with the leg systems, build a solid base out of 4x2 and WPB ply. Kohler and Bette do steel trays, but never tried them. Whatever you go for check it the day it arrives for flatness and store it flat.

The roofing membrane should definitely direct water out of the building, upload the actual drawing and we will see.

Personally I prefer the look of a wrought iron type gate. A solid gate may appear less "friendly" or welcoming, however I do see the benefit of preventing nosy parkers from looking in. However a potential burglar will get over either. I don't think an always partially open gate is sensible, but certainly openable via intercom etc. You could consider a seperate pedestrian gate, but far better to have an intercom to allow deliver drivers entry.

I know at the minute you don't like the look of the roof, but you will not notice it. At the minute you are looking at the roof, but you genuinely don't examine the roof so much once you are in. There is also the consideration that by removing the end slates now they won't be as well fixed as if they had been fixed in your preferred way from the start. Give your roofers a break and accept it "as is" There are much better things to spend your money on, even if you have a fixes price you end up paying for it one way or another.

You can't really tell what the root of the problem is until you get a few tiles up and see if the floor is actually moving

If water gets past the grout/tiles, it runs down the tanking membrane and onto the tanking tape which is lapped onto the bath/shower tray, thus directing the water back into the tray rather than the board behind getting wetter and wetter until it eventually shows on your celing below

If pantry, utility and cloaks are all extensions then @DevilDamois 100% right and this is not PD. His drawing above makes your PD rights clear. Doesn't mean it will be turned down if you apply.