Mike

I'm adding both to mine - though it's true I'll be living in it initially myself. I agree that MVHR is less well appreciated at the moment, but it's growing - and also difficult to retrofit. MVHR reminds me of debates I regularly in the 80's had back in to 80's with clients who didn't think it was worth fitting double glazing. By the 90s everyone wanted it.

While I'd treat it as a last resort, in theory you could consider taking legal action for nuisance based on the precedent of Rylands v Fletcher. But a filter would be cheaper.

Make it wider still - the full length of the wall cupboards?

I've not yet taken a decision to go with any of the options (if any) yet, but compared to the UK per-person average water use (around 140 litres / day), the water usage is high. One installer's web site suggests it may require 140 - 170 litres / hour to cool my 40m². The hottest weather may also coincide with droughts or restrictions on water use.

If you're wiring per room, then I'm pretty certain you can use 2.5mm T&E radial wiring with a 20A MCB to serve up to 50m², which is probably enough except in a kitchen or utility room.

I'm choosing mini flat panel LEDs.

Check the BBA certificate for the brand of OSB that you're using, just in case, but in general 18mm OSB3 is suitable for flooring over 400mm centres (potentially up to 600mm). For bathrooms & shower rooms I would personally upgrade to an external plywood.

It is a good sized room, however two sides of it are effectively corridors, so the 'core' of the kitchen is 3 x 3.86m (including the full depth of the island, which in practice wouldn't all be readily usable from the 'kitchen' side), and you have 3 entrances / exits from the core. That doesn't mean that you can't have a very good and efficient kitchen, but it does need careful planning.

My only additional comment would be to move the hob so that it is around 300mm away from the side of the island unit. As currently proposed pan handles are likely to project beyond the worktop edge, which could be dangerous. In such a restricted kitchen I'd personally move the hob to the room perimeter, and keep the island for preparation & serving.

You could also consider changing the shower. In particular check out the latest version of the Moen Nebia which uses atomising technology to cut water use to between 3.5 and 5 litres per minute (compared to between 8 and 15 litres / minute for a regular shower head). No direct experience yet, but on balance the reviews seem positive, so I'm likely to install one in my next build.

That was probably a cheap way of meeting fire door requirements - a door to an integral garage must be a fire door. If you have a fire door with intumescent strips and smoke seals I would expect that you could use thinner door stops, and could probably replace them with an alternative timber, but to be covered legally you would need to ask the door manufacturer for advice (the Fire Door Alliance advise that the door and lining is certified as a set).

You could also consider installing a micro hydro turbine.

I'd probably use vertical battens hanging from the rafter ends at the top, with additional anchors at vertical intervals fixed through the insulation back to the wall (using something like the Fischer Thermax / EJOT SDF S 10H, if the insulation isn't too thick). I'd avoid aerated block as it tends to crack, however if you do use it you might just get away with using warm roof nails instead of screwed anchors.

The regs were changed in about 1985, and unvented cylinders and combi boilers have certainly taken off since then, and to some extent thermal stores. No statistics, but I don't think many new builds to have vented cylinders these days. Many mixer taps are also only suited to mains pressure hot water so, if you don't go that way, check before you buy.

I was taught that to avoid that - theoretically the tie wouldn't be so well embedded, and there would be a small risk of damaging the DPC - but you could check the Agrément certificate for your wall ties and DPC and see what they say. It isn't allowed for Ancon ties, for example (The first run of ties is to be laid as near as possible to, though not directly on, the damp-proof course).

If you're fitting worktops butting up between 2 parallel walls, you'd probably struggle to fit it if you only had 2.5mm tolerance. Bog standard ceramic tiles will be 5mm thick, + 3mm adhesive, gives you 8mm either side / 16mm total, so loosing 10mm is no problem.

Gypsum screeds aren't water-resistant, so take care if you're planning a wet room.

Provided you don't have them cut to the tight dimensions, and aren't too out of square, it's easy to loose 10 or more under wall tiles and sealant.

Some online companies will sell worktops to size, including cutting mitres, so you only need to fit them.

+1 Water pipes are also more robust without much to go wrong.

When I did my last, I used the excess concrete to progressively place the foundation for driveway kerbs.

I'm sure that we can help with that, if you share details of your neighbour's proposal & the structure of the wall. BTW, if it's a new extension, I presume that it's the original house that's moving, not your extension?

It would be helpful to know more about the structure of the wall and the proposed means of fixing, but I can't see an obvious reason why damp - or anything else - would be a significant risk. The biggest long-term issue could be rust staining, but stainless steel fixings could be used to avoid that. The biggest source of potential 'damage' would probably be the formation of green algae in the shade of plants grown next to the wall, but you can't stop a neighbour growing plants (unless, perhaps, ivy gets seriously out of hand).

If your other ground floor rooms have timber floors, you need to either add ducts below any new solid extension floor and terminating in airbricks (to ventilate the timber floors), or replace them with solid floors too, as @Mr Punter suggests.

Domestic closers were dropped (except for integral garages) due to a report in 2003 identifying over 30,000 finger-trap injuries each year, plus evidence that many people disabled the closers or wedged the doors. Instead there was supposed to be awareness campaigns advising people to shut their internal doors at night (all doors, as most people didn't know if they had fire doors or not). Obviously if the shut door is a fire door, you have better protection. Leave it open and it is indeed pointless.