Mr Punter

I see what you mean about the slight plum tinge but there is not much you can do about it now. Once you have fascia, gutters and external wall finishes installed and after a year of weathering I doubt you or anyone would notice. I had some dark grey Sandtoft 2020 clay tiles fitted on a project and was surprised that the grey colour was a coating rather than the natural clay colour.

Yes, an error there. It would take a lot of paint to cover 1.5km2, as it is 1.5 million square metres and would take about 150,000 litres of paint to do a single coat.

Keep the windows and doors open during the day when it is warm and dry outside. If you have a dehumidifier, close doors and windows and run it at night.

Opening and stirring paint, moving hoses, cleaning up, moving sprayer, demasking. They were 3 x 3 storey houses. The spraying was less than 2 days. A lot of paint. They also had a roller that was fed paint by a hose that they used for rendered walls, so no faffing with a scuttle.

Spraying is quick but the prep can take ages. Also, any touching in looks bad and tape and fill jointing really shows up under some lighting. I had some houses sprayed and they had a team of 4 with 1 guy on the nozzle.

Yes I would fix a temporary timber to the face of the brickwork and cast a sand cement infill on top of the ali cill for the back of the first paver to rest on.

I am not sure of your setup but a raised tray can help if the fall is tight. They can look fine and can allow better access. Noggins or joist trimming may also be an option.

And I think there may be a small issue with the dust extraction...

If it is the case that you could buy the plot without needing to sell your place it would be a more compelling proposition. Is your offer subject to anything else (planning, easements, etc.)?

I thought you were going wall hung, hence the frame?

What is on top of the XPS? Is the garage heated / "conditioned"?

If they are not carrying current I don't see what this would have to do with BC. If they are compromising a fire rated ceiling or floor you would need to fire stop them.

I don't think you are missing anything. The way buildings behave can be very complicated. Building geometry, local climate, weather, occupancy lifestyle, heating, ventilation and insulation will all impact roof condensation.

+1 I have used these and they work well. You do need a perimeter edge to retain the paving but that is the case whatever you do.

A while ago my next door neighbour locked themselves out of the house. After a while it was decided to break a window at the back to gain entry. I was voted for the job. It took over 5 minutes with a hammer to get through the triple glazing.

Fermacell is Gypsum based, like plasterboard. It is not as brittle as cement board. No special requirements for tiling as far as I know. You have done well if you have managed to line the whole place with Fermacell as it is heavy and difficult to cut and fix.

You should keep your patio level 150mm below DPC to avoid damp issues. Patio level with internal floor level is asking for trouble.

I think coring a hole and installing as per your drawing will be good. I have not seen these before but they look decent.

Any less would be bouncy and not reassuring to walk on. Rafters would need to be 400 as well.

It will be fine if the rainwater connects into a combined drain. I don't know anyone who has ever changed the limestone chippings in the soakaway version.

Cavity barriers and firestopping is often left to "others". They often get left out as nobody really knows what to specify or order or fit. Were they specified and detailed on the architects drawings? Rockwool would be a decent choice for non-vented and Envirograf for intumescent, vented rainscreen applications. I would want detailed spec and drawings, so nothing gets missed on your order or on site.

I really like the XPS backer boards. Lots of thicknesses, lightweight, easy to cut and fix, waterproof. Fix with adhesive foam or screws and washers.

Can you clarify if you intend to extend the existing ground floor, also adding a basement under? Without a floor plan there is a limited amount anyone can suggest. I think that having a measured survey of the existing building and plot would be a good start. Have it include a section through the house / plot, neighbouring properties, front and rear elevations. Budget £1,200. Make sure you own the rights to use the plans.

If the rooflights are toughened and laminated the requirement for balustrade may be reduced anyway. Don't forget access for cleaning with all that glass.

Well that is good to hear. My experience has been that they have been difficult to deal with, I could not get the online part to work. They often want to send out a salesperson but I had issues getting prices. I would like to use them, as they have a branch near me but they are not easy to do business with.