ProDave

A change of direction in the middle of a "room" is a bad idea. Some makes of T&G panel have a slightly different profile to the side and end t&g profile meaing they will never line up dead level.

Crane will be £1000 at least. Are the battens structural? If like our floor they are what the floor boards fit to, and the screed between them is just a non structural heat dispersal medium, then it becomes a completely DIY job if you are up to it. I did half that area myself with 1 mixer and 1 barrow.

First plot we bought 20 years ago, the vendor had already done percolation tests and deigned a system with a drainage field under the field behind us, and already negotiated a right of servitude with the land owner to allow that. So that one was low risk. Recent plot, no such pre planning. We bought the plot because we wanted it, it was 2 doors up the road from our first build, so we already knew the geography. It was a larger plot, with enough toom for a drainage field on our own land. BUT it has a seasonal high water table. We got outline planning on the basis of building a filter mound drainage system in our garden. Come to building regs time, they rejected that, and a second alternative plan. Squeaky bum time, plot with no building warrant. It was solved for us by SEPA allowing a treatment plant discharging to the burn running through our garden. Up here they only allow discharge to a watercourse if there are no other options.

I recall years ago an employer of mine wanted to enlarge their car park. They used this sort of system where a wooden former was put in place with a much steeper angle than the natural angle of repose. A layer of soil was poured and compacted against this former. Then the former removed and the material and seeding wrapped over the exposed edge. Then the former replaced a layer up and another layer of soil laid and them more material and seeding. It was repeated until they reached the top. It did succeed in holding up the enlarged car park, but I would not want to trust it to hold a building up.

We get a little condensation on the Eurolocks on the inside of our Rationel doors. Only a little and only when very cold outside. It is a fact of metal parts that pass through the door. The Rationel doors have a similar plastic / foam part that does it's best to block draughts and maintain some insulation in that area, but the fact is with the door handle you have a solid steel shaft passing through. Unless Internorm have designed a shaft with a thermally insulating section that still maintains the strength normally provided by a metal part?

Compacted MOT1 does not drain well, so don't expect water to drain through it quickly, so a fall would make great sense.

+1 to tile first. THEN check floor to floor height, it might not be exactly what you expected, before ordering the stairs.

If you have treated mains water into an unvented tank. there should be no bacteria in the incoming water and no way for any to get in, so several people have concluded it is pointless to heat it hotter once a week. Private water or vented cylinder, yes you do need to do it.

Option 2, pictured in your first post, is the standard way of fitting windows in brick / block / stone clad timber frame houses in Scotland.

Devil's advocate: Converting that garage will turn your semi detached house to mid terrace and may devalue it.

Are you normally in at the rogue time? If so keep an eye on the power usage and when you see the spike, start turning circuits off one at a time at the consumer unit to see which one it is.

If your immersion has a local isolating switch, turn that off and see if the rogue power stops.

I am sure it is doable, but strongly suspect with those rafters it is roof completely off and start again so may not be cost effective.

OV10 vent in place of or on top of very bottom tile batten https://www.roofingventilation.co.uk/Over-Fascia-Vent-10mm-x-1m-Harcon-OV10

I have said for ages that is a load of tosh. Thankfully people are recognising that. I look forward to the announcement that DRAX is finally closing.

Another point about Jeremys spreadsheet. The last part, where he inputs OAT data and predicts monthly heating requirement is flawed. If I look at the figures I have, which still has the OAT data for where Jeremy lives which is a lot milder than here, it gives me monthly values way higher that reality. In particular I find OAT of 10 degrees is a tipping point for us. 10 degrees or more and we don't need any heating at all. Yet Jeremy's spreadsheed is still calculating a June / July / August heat loss where nobody will be using any heating.

I have said before we have a WBS because we have wood. If I did not have my own stove the wood would be waste, it is not good enough to make anything with, so it would either go to someone else to burn in a stove or worse still get burned outside.

It sounds like a ploy to put lots of non Chinese production plants out of business. So this could be a relatively short over production, as capacity will reduce and the lower prices will increase demand. Keep an eye on the market and catch the sweet spot.

It seems somewhat illogical that you have a EA permit for foul water disposal, and are now struggling with rainwater disposal. I would not have thought rainwater soaking into the ground would be a bother even in protection zone 1. Have you actually submitted a design to the EA and had it refused?

Air change less than 3 in Scotland triggers the need for MVHR, so the mass builders will aim for just under 5 to pass without it.

My ASHP is on a south facing wall. In winter on a still day here, the front of the house that does not get any sun can stay cold and frosty all day long. The south that gets any sun going, warms up and the frost melts. I cannot believe being on the warmer side of the house has no positive effect on the ASHP performance.

I have one in my boat as well, they work well for a small space but as above make sure they are installed properly.

We were talking about this earlier. Over the last perhaps 10 years, around us all public buildings like schools, leisure centres have moved over to wood pellet boilers for their heating. So now the Scottish Government have banned such things, will we see these now replaced with heat pumps?

It is possible, I wired a whole house where the owner wanted OSB as the wall finish everywhere. The builder found a clear coating that was acceptable to building control, but sorry I don't know what it was.

The suppliers make it hard for themselves (and us) The only thing that separates THTC from E7/10 is the second meter that meters the 24/7 cheap rate. In it's simplest form, to convert from THCT to E7 they just need to remove the second meter, leaving the existing dual rate meter and time switch, and connect the feed to the heating circuits to the normal rate feed with a henley block. An electrician can't do that as we are not allowed to touch the metering. I don't know why the suppliers cannot just offer that as a simple option. That still leaves the radio teleswitch that will need replacing some day whether or not you change to E7 or stay with THCT, that is a problem yet to solve. As I understand it, in the absence of a radio signal it becomes a dumb timer so on / off periods may creep a litte depending how accurate it is. Not sure how it handles a power cut. As a temporary measure they could always fit a mechanical timer, remember the old Sangmo Weston timers that were clockwork with spring backup for a power cut?