garrymartin

I hate these sort of answers, but it very much depends on the frames you'll be putting in for those doors, to which you would then need to add 2-3mm clearance each side and at the top, and a bottom gap depending on flooring etc. If you've looked at some doors you like, see if the vendor also provides doorsets for them that you would be happy with, and then they should be able to provide you with the structural opening sizes. For example, the link below is JELD-WEN ReadyFIT guidance. https://www.jeld-wen.co.uk/getmedia/03ec61f5-3ec5-4be4-8e78-d5b1abd44743/readyfit-structural-and-clear-opening-sizes.pdf.aspx

Your PS suspicion is correct, as has been observed by @Russell griffiths and @Nickfromwales - the panel should have gone to the floor. Fixing/changing this is by far the best option. Then, when it comes to what to do with the skirting, knowing the type and the profile would help with regard to how best to finish it. Is it a square profile?

It's a bath filler.

Not the best photo, but I can't find anything better - this is push-fit (Flomasta I think) 22mm x 3/4" BSP male in the iBox. Worked really well.

Click is a Scolmore brand https://scolmore.com/products/type-a-c-usb-sockets

Yes, USB-C generally charges much faster than USB-A, although it really depends on what you are charging, the cable you are using, and the capability of whatever sits beyond the actual port. Some USB-C ports with Power Delivery (PD) can pump out 240W compared to a USB-A port rated at 2.4A pushing out just 12W.

@-rick- has some great advice there, and I would echo every comment, especially those related to making an electrician's job just a little more difficult! Connector types and abilities have changed greatly in a relatively short space of time, so you don't want something that might be obsolete in a couple of years, or not as performant as you'd like. I'd also add that cables and connectors are more prone to damage when they come out of a socket at a 90-degree angle, and it's also difficult to push furniture back against them (as an example). I'd much prefer a plug-in adapter where the cable exits at 180-degrees below the outlet. Hope I've explained that correctly! Like in this image...

It's in Part B somewhere, but I think it's 100mm not 150mm. You can also meet the requirement by having the floor slope away from the threshold, so it isn't mandatory. It's something to do with preventing diesel/petrol spills migrating from the garage into the house. EDIT - I decided to find it... Section 5.7

Spot on. Passivhaus is only of near-equal cost parity if the building was designed to be Passivhaus from the beginning, including principles of form factor. If someone has designed a home, and then tries to make it Passivhaus, then you are almost in retrofit territory, which of course costs more. I think you can do one-offs too at significantly less than 30% increase in costs, but as above, you need to design from the outset. The garage door is a great example earlier in this thread. It looks like the architect/designer didn't consider this at the outset, and possibly made the fire *and* airtightness barrier/boundary the same, causing the requirement for an airtight and thermally efficient fire door, which was very costly. Separating those elements (fire/airtight) at the design stage may have resulted in signficantly less cost. It may not have been possible given site or design constraints, but just one example.

It very much depends on form-factor (easier to make savings on apartment blocks than one-off detached houses), but it is nowhere near 30%, and in some cases has been shown to deliver savings. And of course it also depends on whether you are certifying or just building to the same standards. This article https://www.coldwellsbuild.com/journal/are-passivhaus-homes-more-expensive-to-build has some better links, including to an Exeter City Council report showing how they have continued to reduce costs over the years - "Due to Exeter’s long-term commitment to Passivhaus they have developed unique expertise and experience which has enabled them to refine their delivery models and processes to drive down the cost of Passivhaus. This is reflected in the reduction in the cost premium for Passivhaus from 20 per cent in 2009 to 4 per cent cost saving, pre-covid for apartments up to 4 storeys based on the cost plans against Building Regulation compliant low-rise apartments." https://www.local.gov.uk/case-studies/exeter-city-council-passivhaus-exeter

We have a very similar setup for switches and sockets. The only thing I can add from experience is to think about the bedside tables you are going to use (if any). The shelf of ours is right at the height of the sockets, so it means you can't fully push the cabinet back to the wall, and you have to pull it out to plug and unplug items. Small thing but annoying nonetheless!

Creating a sample is always the best way. You can then also get approval from the other half before manufacture! 😉 What you might also want to consider, given that it is custom and if you feel your woodworking skills are up to it, is stopping the grooves short where your sockets will go, giving yourself a 20-30mm perimeter of the solid wood. Something else to play with on a sample perhaps?

Not sure why I ended up reading the Toolstation reviews, but if you are attempting something @ProDave just be aware that one of the reviews says "Designed for single use so not ideal. Can be disassembled to enable reuse with a little gentle persuasion." Might be wise to use the coupler approach if you do anything rather than try to disassemble the elbow...

Yes. Perfectly OK for 3 and very easy for your electrician to make it 4 if you wanted.

Was the roof height raised to get more internal height for ground and first floors, and the windows moved up? Has it been checked out, structurally?