Ed Davies

Yep, though there's another effect going in the opposite direction: normally with UFH the radiant temperature in the room will be more than with other forms of heating (UFH puts out a larger proportion of its heat as thermal IR than “radiators” or most other heating devices) so the air temperature can be a bit lower for the same apparent temperature for occupants and so the ventilation heat losses (particularly without MVHR) will be lower. I haven't done any arithmetic but I suspect the increased heat loss through the floor with UFH would be a larger effect but radiant temperature vs air temperature needs to be taken into account.

The graph is broadly good news, of course; better than most other countries. Far from enough though. The bad news is that the power sector reductions aren't likely to be continued at anything like the same rate as they were because the biggest reduction has come from the switch from coal to gas and now we have a bunch of gas plants which will need to be used to justify their existence. Actually, if the absolute amount of CO₂ emissions from electricity generation stay flat but the total amount of electricity used increases as it's substituted for petrol, diesel, oil and gas with the bulk of the extra use coming from renewables then that would be a good result. And, yes, I'd agree with @gravelld that air-tightness on the existing housing stock is a big issue. Maybe you shouldn't be able to get a C rating or better without doing a blower door test?

Or the opposite, intermittently dry? Dunno about SE England but September had the ground unusually dry here in the NE of the island.

Wouldn't neutral and earth be the same thing there, combined as PEN in the outer conductor? But, yes, the possibility of an intermittent break there does need to be considered.

The exhaust should be nearly as cold.

SBR?

Do you happen to know if they have any restrictions on what services you can access? E.g., do they say you shouldn't or do they prevent you from using VoIP? I think my current EE mobile SIM's conditions say you're not allowed to use VoIP. I currently have a “wires-only” (no voice calls) copper pair to the exchange for fibre to the cabinet (FTTC, the cabinet's by the exchange) getting 24 Mb/s down which is reasonable. Rather than deal with BT at all I have a VoIP number as my landline. Neighbours where I'm building only get 5 Mb/s down (ADSL rather than FTTC, I assume). That was what I was getting in my previous house in Tongue which was OK but made live video useless. Always downloaded YouTube and watched later. I don't know what I'd get at the house site, yet, of course but suspect it would be similar so would need to pay an extra £10/month for FTTC. Mobile at the house site is pretty good so it would be an option rather than putting in any landline if VoIP was OK.

+ another 1 for SketchUp. It's got its own odd way of operating but once you get used to it works well. Definitely look at some of the tutorials. Use layers and components.

I wondered before but in light of @JSHarris's post I'm going to ask, why @Nickfromwales specify (so emphatically) that the accumulator tee should be after the softener? Is it just a case of not having hard water clog up the accumulator eventually or is there something more subtle? Puzzles me as I'd think the cold water in the accumulator wouldn't be much of a problem for that.

The Wick branch closed earlier this year. Only useful thing I picked up was a reciprocating saw (Bosch, IIRC - not something I'm expecting to use a lot, only used it once so far but that was a 30 metre cut) at half price. Frustrating that there was a lot of stuff which was almost useful but not quite what I wanted. Big pile of 18mm OSB3 I didn't think I needed then decided a week later that I did, went back and all gone of course. Still, it was only £6/sheet cheaper than my usual timber merchant.

Better than my mate at school who, when he was about 10, decided he wanted 480 volts so wired two plugs in series. His father was less than entirely pleased.

Guessing, but maybe they put it in to get the right SAP rating with the intention of switching to gas ASAP.

I don't think I've had more than ten minutes conversation with any building “professional” who hasn't said something which some understanding of basic physics and a little reading round the subject hasn't told me is complete nonsense. Not that I haven't learned a lot from those conversations, too, but it all needs to be carefully filtered. The fundamental problem, I think, is that for traditional reasons building is an illiterate business. Not that builders (necessarily) can't read or write but that it's not the normal way of working unlike almost all other branches of engineering. Instead information is passed on by word of mouth when people are often in a hurry so the what and how gets communicated but not the why with the consequence that people don't have the background to extrapolate beyond the specific methods they've been shown. They're aware of this at some level which puts them on the defensive.

Also a good reason for dealing by email as much as possible. Partly because you'd have a written record (forgeable, of course, if not digitally signed [¹]) but also possibly avoiding a misunderstanding on the phone and giving the person you communicated with time to check what they were saying. E.g., have another look at the datasheet or talk to a colleague. Or even get a meter out. [¹] But then there are lawyers who think faxes are evidence ?

Or a wired Ethernet socket in each room and let them sort their own Wi-Fi out as they like. It's what the hall of residence my nephew stayed in did.

Just to be clear, what does “nothing now” mean? LED off all the time? LED on all the time? LED still going at 1/2 Hz? I'd assume the first but as well to be sure.

I'd imagine this is the sort of consequential loss that terms and conditions exclude so legally they're probably in the clear. But morally, especially as @joe90 specifically checked with them, they'd be asking for a bad reputation if they don't at least contribute substantially to the replacement.

I think plan B wouldn't be too terrible if you were just tiling up the side of the window but if you do that what happens across the top? You'll have to have a small tile, the width of the dwarf wall, in the top right corner. You can't have the join on the left of that not lining up with a join below. So, plan A gets my vote, I'm afraid.

Ah, right. I'd got the order wrong; they're moving away from, rather than towards, removable cells. And thanks for your other description - useful background.

I'm sure I read somewhere about being able to remove the cells to make them easier to move. Maybe Andrew Bissell on Twitter. Perhaps it was something they were considering for the new versions but didn't make it into the product. Aren't there multiple cells in the larger units so removal would split the load up considerably?

Can't you take the cells out of the newer Sunamps to make them easier to move?

For a site which is near permanently water-logged I've had very little trouble with mud. The access track and parking area is built up above the surrounding ground with uncountably many dumper-truck loads of rotten rock from my neighbour's borrow pit (https://edavies.me.uk/2014/05/access/). The actual house site was scrapped down to clay (only a few 100mm below ground level) then covered with 12 tonnes of 20mm Melvich stone (https://edavies.me.uk/2015/06/still-here/). As long as I stay on the parking area and the immediate house site mud hasn't been a problem. Step off that, though, and wellies are needed; ordinary ankle length boots are liable to flooding from one wrong step unless it's been mostly dry for a few weeks. The skylarks which were nesting nearby last year seemed to understand this: they weren't bothered at all by my using power tools only a few metres away from their nests but the moment I stepped off the hard ground I was invading their territory and they were up in the air giving alarm calls. Haven't seen anything like as many this year, I think the beast-from-east weeks earlier in the year stopped them breeding so much.

Seems to me that an advantage of two layers is that you can stagger the joints reducing any air paths if the stuff shrinks or moves a bit.

I think mosaic tiles across there would make the room look low. Could you grout or otherwise fill the whole gap? I expect it'd just visually join on to the ceiling that way.

Yep. Similarly, if the heatpump is in the house then the losses from it contribute to the heating but detract from the cooling. If the HP is outside (as ASHPs usually are) they contribute to the cooling (sort of) but are no help at all for heating.