Mr Punter

These look like Marley Eternit Slates. They are pretty soft compared to genuine slate and they do not last that long. The silicone is a massive bodge. £650 is a piss take.

We once had an old style high level cistern. Nothing would escape it. No turd too big or sticky to resist the torrent from 2m up. No double flushing needed there.

Rationel and Velfac are part of Dovista. Velfac is a composite, with timber frame inner and aluminium sash. Rationel are more like an ali clad timber frame. Solarlux I think mainly do sliding folding doors, connies etc.

You can't have the cladding touching the cill or ground. It will wick up lots of water and rot out in a matter of months. Best practice is at least 150mm gap at the base of cladding. Often this is in brickwork.

The timber frame will shrink and move down in relation to the blockwork. It has probably done most of the shrinking. The blockwork was not designed to take the roof load, so be cautious. It is one for a structural engineer.

I think they were the right way up. The underside top picture shows a rough edge and border. The topside lower picture I think is non slip surface.

Is this meant to be drinking water and if so, has it been tested? Assuming it is fine and passes the tests are you just concerned with flow rates and pressure?

Not GSE, just metal rails. The solar guys attended to inspect and were due to get on the roof to resolve this. I don't know how they got on. Scaffold is down, so I will not be going up there. This only shows on the section of roof with solar.

I have had similar and think it may be condensation:

A very good point. There is often a very vague spec when it comes to this. You can get intumescent fire barriers that you attach to the panel and in the event of fire it will swell and stop the flame. I expect they get purchased and correctly detailed and installed about 2% of the time. Make sure you close the cavity around window openings (with timber or Rockwool) as this is an obvious place for fire to get from the cavity to the inside or vice versa.

Based on the scale, a 2400 room height and 300mm floor zone as per @Russell griffiths, this is how it would be:

Am I right in understanding that this house in Donegal is built using Porotherm blocks, with no cavity, rendered externally and plastered internally? If that is the case it is not surprising it has damp issues. Porotherm is a real Emperor's New Clothes product. Almost no "therm" at all to the stuff and very difficult to cut or fix to. It does have quite high compressive strength and lower density due to the voids.

I have used these several times and they are fine.

The Wedi board XPS type boards are nice to use. Much easier to work with than the cement based likes of Hardi Backer.

I can see that the roof opening was made smaller since it was originally framed but it is not unusual. It looks like the far end trimmer was positioned so that it rested on the nib of wall rather than being a point load on the lintel over the opening and the numpty surveyor did not measure correctly when they came back to measure the completed structural opening with upstands. If you do not get satisfaction from the meeting, issue a letter before action, including the total money amount you seek, which can include additional costs for overheads, administration, prelims, finance costs and profit. Get quotes and lead times from at least 2 firms for the replacement cost. Give them 14 days for receipt of a satisfactory response. If the firm do not agree to pay your claim or make a reasonable offer, issue proceedings. You can do this online.

I am pleased you removed that. I think they are awful and quickly grow much too large for the average garden. Best left to the Aussies.

I would run your proposals past the Building Inspector. You need to be able to rod all the pipe without disconnecting the WCs etc.

@Russell griffiths has built with Nudura and knows his onions.

You can run the bath and basin in normal waste pipe. You could have a waste manifold near the WC to connect everything to. https://www.screwfix.com/p/floplast-push-fit-4-boss-single-socket-waste-manifold-black-110mm/40832 Plus a stub stack and AAV. This should mean just 1 pipe run out.

I think this is no longer considered the case. Years ago there were maximum recommended gradients for drainage. They have now been abandoned as they had no basis in evidence.

I like that they insist on you pointlessly installing insulated ducting under your insulated slab but they gleefully dump untreated sewage into our rivers and seas.

I have only used ducting when I have needed to feed the pipe through later.

You could use Rockwool floor insulation. Not great insulation values but non combustible.

I don't like the ground floor rooms being open to the stairs. Upstairs habitable rooms will all need escape windows. Heat, noise and cooking smells will all go up the stairs.

Tarmac or block paving is better for the apron, especially if there is any slope.