ProDave

What is that "support beam" supporting? It looks too tiny to be doing anything as a "beam"

If you have done first fix and fitted all the vents and ducts, then you have bought and installed the expensive bit. I found the actual MVHR unit cost less than the ducting so you might as well buy it and fit it. For a good portion of the year we sleep with the bedroom window slightly open, but that won't ventilate the whole house so we leave the mvhr on.

No problem, sometimes the shade it creates is welcome. Definitely a well liked and used space.

Dumb question. Is there no water coming out of the hot tap? Or is the "hot" water coming out cold? Not such a dumb question when I as an electrician drove 40 miles for "no hot water" expecting an immersion heater fault, only to find no water coming out of the taps and they needed a plumber.

One of the plumbers will advise I am sure but if you could take another photo with the pipe insulation removed they will see what joins to what more clearly. You have an interesting mixture of actuators. I assume as a result of failures and replacements?

Where are you? Which country? You definitely need one if in Scotland?

Loch Ness is the largest volume of fresh water in the UK, largely thanks to it's depth. It is not the largest surface area of fresh water though. You have to be very hardy to swim in the loch, it's only about 6 degrees and does not vary much. 73cm drop might require some dredging in Loch Dochfour to maintain navigation depth of 3 metres, and adjustment of the weirs to maintain some flow into the River Ness. For context, Loch Ness on a good day.

The traditional usage was pump water up whenever there was surplus and let it down again to generate to fill in the peaks, often for short periods like the late afternoon peak. If longer term storage is intended like to to fill in when there is no wind in the middle of winter then it may need to generate for a week, so would have to be at a very much lower power. I wonder how the Calley canal will cope with the rise and fall, some parts of Loch Dochfour approaching the top lock at Inverness are not that deep and the overfall over the weir keeps the River Ness flowing down through Inverness. Pump too much out of Loch Ness and boats may get stuck and the River Ness through Inverness will dry up. I am sure this has been thought about.......

What are your pre comencement conditions? Ours said we must first create the access from the highway before building work starts. So I created the access and the council confirmed in writing that by doing so the development had started.

Scotland generates most of the renewable wind and hydro power yet we as customers pay the highest prices. SOMETHING has to change. I say we have enough wind farms and there should be no more until the major hills in England like the Cotswolds, Chilterns, Berkshire downs, South Downs etc have the same windfarm density as we have. Build the windfarms nearer where the power is used rather than 400 miles away with more pylons to take the power down south from here.

Sorry misunderstood. Choose a flat metal plate screwed switch (not screwless with clip on cover) and carefully file 2mm off one end of the plate until it fits.

What depth is the back box. Is the "cover" you talk about the light switch? Can you find one that needs less depth (like they all used to when the standard light switch box was 16mm)

Also too deep and you might be below the water table in winter.

One thing I did for possible future runs, is in all the upstairs rooms I put a half board removable section of floor board at each end of the room, so 300mm wide, only screwed down and tongue or groove modified so it can be lifted. This will give access to the posi joist ends and allow additional cables to be pulled through around the room. Your spare conduits could be fitted in the walls as straight runs terminating in this accessible under floor space.

You can get swept bends for conduit which will work https://www.ebay.co.uk/itm/145467409061? Secure the conduit runs well, you don't want it coming apart if trying to fish a wire down later when it is inaccessible. Consider solvent welding the fittings to make sure.