JohnMo

It's just under 24kg a sheet, so density quoted as 650kg/M3 looks correct. So it must float, but not tried it.

Photo, was the best I could find showing a roof light - I have 2 roof lights. They form a cover for the upstand and it all welded together.

Not sure would like that, wife would definitely throw the teddy. We settled on french doors and fixed panel. Ours is 2.7m wide, but could easily be upscaled. We have a lock on the outside, for ease of use. Also just been air tested no leaks.

Switching options are, may be others but not aware of any. Humidistat, but these are not great in the UK climate and humidity swings with seasons. PIR could be with a delay timer, in and out in a minute does nothing, anything longer for example a shower or a number 2 it comes on. Manual switch, our MVHR has humidistat, but is pretty rubbish, so use manual switch by light switch to make boost when showering etc. Light Switching, as you mention no light on, no fan on.

Our roof is at a 12 degree angle, we used EPDM (Sarnafil) which has all seams hot air welded.

Pretty unlikely, you normally don't here anything until or after that date, irrespective of the decision.

We used https://www.realstonecladding.co.uk/natural-stone-cladding-panels Real stone, not composite

Or you could go for something similar to this, with integrated PIR https://www.tlc-direct.co.uk/Products/SLEA4DLC.html

Go to an electrical wholesalers/ trade place, ask them what it is. If they have no idea it a good glue no one uses it, if people do, it will be on the shelf.

If they are building and priced to your building spec, they have a contractual obligation to build to your drawing spec. and to a good standard. The foil missing from plasterboard will allow moisture to pass through the plasterboard, where vapour could condense to water and cause issues. Insulation missing will affect your long term heating costs for the worse. Spilling insulation is poor workmanship.

I used airtight paint. But I would wait until you have screed down. Not sure parge would be very successful, it wasn't when I did mine, hence using airtight paint.

Anyone employed to do work by the builder, has a contract with the builder, you as the end user are not part of the contract in any shape or form. Do as stated above

OK

First the OSB layer has done 90% of your airtightness especially if you use airtight OSB on the joints to worry about. Or if using a membrane a great flat surface to affix to. Your service cavity will have your plumbing and electric stuff within it, why would you want then to make loads of holes for light switches etc in the OSB to allow it to be installed? Seems like a double work effort to me for less gain

Looking at your wall build with respect your service cavity. You have plasterboard, OSB, batten for service cavity. This should be plasterboard, batten for service cavity, OSB. If you floor has a ventilation within the void it's there for good reason. If your insulation is above the ventilation why are you worried?

We had a 1830s sandstone house lathe and plaster walls. Wall about 3 foot thick, still got really hot in summer. No insulation to speak of. But wasn't so bad to heat in the winter. New house has 47 Tonne of concrete in the floor, Durisol walls, be but can still get really hot from solar gain; if you let the sun in for too long. Maybe we get longer exposure to the sun, before it gets too hot,compared to a lightweight house, but difficult to compare.

If woodcrete ICF, directly attach with external flexible tile cement. If EPS maybe the same, but not sure.

To complete the thread, I have attached an approved G98 Schematic, now my system has been approved by DNO. Also included was the G98 form completed. Electrical Contractor signed as installer. I signed everything else. Also attached type approval certificate for the inverter with my application. G98 PV Schematic example.pdf

We had a similar issue at or old house, speed all over the place. Took them lots of visits to identify the issue. We call them they would test while I was in the phone and mostly they would identify an issue. Send engineer out, he would find nothing. Issue was finally found as a broken wire on a pole down the road.

We just used battens. The battens are vertical, but mainly because I had counter battens at the rafters to increase insulation thickness and kill off repeat bridges.

Similar to ours we used taper edge plasterboard, which taped and jointed, not skimmed. 9 months since jointing and taping no cracks.

As many are aware I built with Durisol, as first time builder. It was chosen for four reasons. I could do it myself and had witnessed two builds underway prior to ordering, the two self builders were on top of what they were doing and I could freely ask questions. Second, the build manual was clear easy to understand, as long as you follow the 6 layers then a pour and use the corner, end and normal blocks correctly there should be no issues Third the system did not require any special props or much in the way support except with OSB screwed to cut joints and at corners. Very little rebar required. I followed the instruction manual, had no blow outs, no sagging window or door openings, very little block movement during the pours. I think most people have issues because they think they know what to do, don't read the manual, build too many rows between pours. Only real criticism and thing I would change. 1, the blocks do not have parallel sides, this does lead to a bit of rework, until you realise. Possible redesign of moulds could fix this A thing not well covered in the manual is airtightness, this should be beefed up.

Welcome. Are you doing a timber structural for this build? How are you heating the house? Are you building yourselves or getting someone to do it for you?

I would do wet or even electric UFH in bathroom/ en-suites and electric towel rads (for towel drying, not heating 300 to 400W). And provision for an electric panel heater in bedrooms. UFH in bedrooms has no real place, we have it and its a complete waste. Very slow to heat up and even slower to cool down. You need (possibly) a warm hour in the morning and evening. But cool when you go to bed. I would keep the cash in your pocket.

We had a similar issue about 10 years ago. Basically the size of the garage lent it's self to converted into house. The roof angle added to that feeling. Which is really what the planner were objecting to in our case. Maybe yours is similar. We made the footprint bigger and changed the roof steepness ( much shallower) the plans went through fine. In our case they didn't like the room in roof aspect/possibility.