Mr Punter

I can see you are looking at building a 4 bed house of around 250m2. Do you have a budget set? This will cost between £200k to £600k depending on whether you do it all yourself to a basic standard or hand it to someone to deliver a top spec building. You will need to select an architect for this project. Shop around very carefully. Look at the style of building they have designed and if you are able to, talk to their clients. Look to apply for detailed planning in, perhaps, six months time, as your architect (if they are any good) will probably have a number of projects on the go and the design is often an iterative process, as is the planning application.

I would run the brickwork up to 25mm from the timber frame return. On the timber clad wall, form a corner from 2 pieces of larch ripped down to 75mm. Butt 1 side of this corner to the brickwork and the other fix to your timber batten having run some dpc vertically. Bring out the timber battens on this section to the same depth of your batten + corner. You may need to add an extra stud or 2 to the timber frame to support the corner.

Good for high ceilings too.

This will make the UFH very slow to react. Also there will be heat lost to the ceiling below. The optimum concrete / screed or whatever is probably between 50 and 150mm, with a bit of insulation under to stop the heat going downwards.

Concrete is heavy and expensive and that is a very deep makeup for residential. If it is deflection or sound insulation you are interested in, compare it with timber / engineered joist solutions. 15mm plasterboard is better than 12.5 as it is less likely to sag.

Thanks @JSHarris that is good to know, as I prefer not to need to add a caveat saying "The charge point will only be compliant if you install a TT island and you will be responsible for any damage to underground services."

@JSHarris & @ProDave I know it is off topic but this is one of the charge points. Would it be unsafe to use?

I have had 7 charge Rolec BasicCharge pedestals installed on residential driveways without TT islands, as there was too great a risk of damaging other services where they were fairly congested underground. Is the risk just to do with a neutral fault on the network that is undetected?

I make it 170mm dig down from the IC cover (but 15mm wont make much difference).

@lizzie what is the difference? I found the kettle furred up before we fitted ours.

I understood that it was 45m between inspection chambers. I also think you could just put a rodding eye for the foul and not bother with the surface water. Ask Marley or Polypipe technical for backup if required. Easier to send them a drawing than mess with digging up drains.

I have a Combimate, where you have to change some magic marbles in once a year. The kettle does not fur up but there is still residue where cold water evaporates such as in the tray of the fridge water dispenser, in spite of the fridge also having a water filter.

As far as foundations and NHBC / LABC go, for retained or proposed trees it makes no difference on the size of the tree, just species, proximity and soil type.

I don't see dry lining contractors using collated screw guns. Maybe @nod will comment as it is his field. A friend bought one and it was prone to jamming and the screws are expensive.

Or these bits (and I have certainly done far worse):

I would have thought plasterboard and skim would be OK. Why did you rule it out? BTW that is a VERY impressive range of back boxes on the left!

Oh dear I was using the paved are data. Should be 2.64!

Yes as @JSHarris says. Assuming the most negative you would have 0.016l/s/m2 so 0.016 * 120 = 1.92l/s. Can I have some of the £1,350?

I think metal stud for ICF and brick and block, timber stud for timber frame and I would get the TF company to do it. Get them to quote to insulate the walls as well.

I have only ever done floating chipboard over a solid floor, as I would fear the joins weakening if not fixed to the joists. We used a product called ScreedBoard in a flat conversion. It is an overlay board with a soft backing so you would fit this over your chipboard. The sound test results were excellent.

Drain rods or Cobra rod must be easier than digging and then making holes in the pipe.

Drain rods without fittings (you may need to borrow some extra sets) will let you establish where the blockage is.

Access seems pretty good. Was it garages on the plot before? Well done on the VAT. It is easy just to let these thing go and regret it later. Hopefully the weather will stay good for you.

I think it is worth waiting a year, unless there are bits that will be a real pain to get to later on (like your swimming pool ceiling or the tiger enclosure).

I find multi tools and petrol strimmers much noisier than impact drivers. And Paslode guns indoors.