jack

Welcome to BuildHub. A couple of points (I'm sure there are others): ASHPs don't heat water as hot as gas boilers do, so you'll want a larger tank to deliver the same amount of water to things like showers. Make sure you get a tank with a heat pump coil, which is longer than a standard coil for use with, e.g., a gas boiler. A longer coil allows for better transfer of heat into the water.

https://www.instagram.com/reel/DLolteQt7Vz/

From ~10 years of reading BuildHub threads, one general principle pops up again and again when it comes to building problems: the junction where one trade's work meets another. The timber frame company's work isn't square? Foundation guy's fault. Plasterboarding guy having trouble? Timber frame guy's fault. Windows a problem? Supplier says it's the installer's fault, installer says it's the supplier's fault. Roof issues? Roofer says the blockwork isn't level and it's the best they can do, take it up with the brickie. Costs aside, for my money there's huge value in being able to point at a potential problem and identify the one person who is responsible. I suspect that in some cases there are fewer chances of problems if it's all the responsibility of one entity, because there's less temptation to cut corners at each stage. If I wanted a shell built, I'd get someone in to do it. That's what we did. And of course, the two biggest subsequent problems were windows and roofing. The window installers blamed the framing company for some of their difficulties, even though they'd approved all measurements and external battening before arriving. The roofers blamed the timber frame company for ongoing leaks before the house was completely watertight. The leaks turned out to be 100% the fault of the roofers.

Our house can get very hot upstairs during long runs of hot days. I've not got around to setting it up yet, but I have plans to boost the MVHR during the cheap overnight period when conditions are such that the summer bypass function is enabled.

No wonder you haven't finished the build yet.

At a guess, some combination of incompetence, malice, disengagement, and self-interest on behalf of the council and its employees. Whatever the cause, the outcome has in many cases been deeply unfair. I can't see any reasonable basis for the requirement that every CIL box be ticked before you can even trim a hedge or lay some hardcore, for example. If the law is meant to be that self-builders don't pay, then the law's intention shouldn't be subvertable by councils requiring that a set of narrow formal requirements must all be met before an early, arbitrary, and unextendible deadline. It reminds me a lot of how the VAT self-build refund was operating for a while. The clear intention of the law is for self-builders to be able to recover VAT, but HMRC did everything in its power to subvert that intention by using a definition of "complete" that was completely at odds with any reasonable meaning of the word, and was certainly contrary to how it was used in the legislation.

Sounds like clients in every industry!

The last two or three issues of Private Eye have briefly addressed local council abuses of the CIL system, and this person's plight with Waverley council in particular. I don't know much about CIL (it didn't apply when I built), but I'm aware that there are huge potential financial traps for the unwary. Perhaps we should add a sticky post with a warning in the relevant sub-forum.

On my (Brink) unit (and I imagine most other modern units), bypass mode mode is automatically entered based on (among other things) the difference between internal and external temps. Assuming an automatic system, what prompts clients to ask you about it? Do they tend to get concerned that it isn't coming on during hot days in summer? Yes, but if it's automatic, summer bypass mode won't come on unless it's cooler outside than inside. Are there many/any current units that only have a manually-operable summer bypass mode? For us, summer bypass tends to kick in during the evening on hot days when the outside temperature drops below a threshold. It turns off the following morning if/when the outside temperature rises sufficiently. Perhaps less of an issue in Scotland, where overheating is presumably less common? That said, is your unit configured to operate automatically based on the difference between inside and outside temps? If so, why wouldn't you just leave it operating so you get the benefit of cooler air bypassing the heat exchanger overnight if your house is too warm?

They look okay to me. The only issue I have is the lack of edging/boundary between the edges and the adjacent grass. The edges will quickly become untidy unless regularly maintained.

Very interesting. You're the first person I can recall who's done this. I've said before that if were doing another build, we'd have some sort of screed on the first floor, with tiles on top. In summer, the floors would be cooled as needed. For winter, they'd be warmed just enough to keep the rooms at a comfortable sleeping temperature, with temporary rugs around beds and along halls. Depends on how tall the windows are. We have 400 mm overhangs on all south-facing windows. Some of the windows are very wide but only maybe 500 mm tall, so they're completely shaded when the sun is high and to the south in mid-summer. This is very effective. The south-facing sliding doors don't get much benefit from the same overhang. I can give a concrete example of how important external shading can be. Our bedroom is at the east end of the house. For cost reasons, we idiotically decided not to include external blinds on the large east-facing window/door that looks out onto our balcony. The balcony isn't very deep, but it's covered, so there's a 1000+ mm overhang over the east-facing window/door. One of the other bedrooms is west-facing. It only has a 600 mm overhang. It has a big window too, but has external venetians that are only ever partly open during summer. There's a permanent temperature difference between these two rooms throughout summer. In very hot periods, the difference can be several degrees. The difference in comfort between 22 and 27 degrees is marked, especially when you're trying to sleep! I wish we'd provided for these, as they're not really practical to retrofit! If there's doubt about whether they'll be needed/wanted, it wouldn't cost too much to add the required (insulated) runs at first fix, but only install the fancoil units if needed. I think you also need to consider condensation drainage, depending on the temperature you plan to run them at. I've heard this can be effective, but it seems like an expensive and complicated option with a high risk of failure over a long enough period of time. External shutters or blinds feel like they'd be as effective. More generally, I'd also consider careful selection of plants. For example, a deciduous tree in the right place can provide a lot of useful shade in the summer. Same with deciduous vines on a trellis or pergola.

I took the opposite from @-rick-'s comment: "without [the Germans] the rest of us would be stuck with [worse] privacy laws much more in line with the US than we have."

What's she measuring that distance from? There's zero chance the boundary position is defined with a resolution of 7 cm. Tell her to go jump.

MVHR doesn't have anything like the airflow needed to provide serious cooling. Design in air conditioning (completely separate from the MVHR), and throw on some PV so you can run it for free on hot days. MVHR will help keep the heat outside.

I was talking about ordinary condenser dryers (like the one I have), not heat pump condenser dryers. Non heat pump versions definitely use room air to cool the condenser:

The heat exchanger does not mix moist air from the drum with cooler air from the room. The room air is used to reduce the temperature of the condensing surfaces within the heat exchanger. The warm, moist air from the drum is passed over the cooled condensing surfaces, but on the other side of the surfaces from the room air, hence no mixing. Moisture condenses out and is sent to a drain or container (which must be emptied periodically). While the air from the room is warmed, it does not absorb any moisture, hence there's nothing to condense. We have a [edited to add:](non heat pump) condenser dryer. While our utility room tends to be warmer than the rest of the house, especially in winter, the temperature difference isn't excessive.

Much better job than any of the many plumbers I've used over the years!

Most likely they're proposing this because that's how it's generally been done. Stuctural slab (no insulation underneath), insulation (and historically not much of it), then a screed on top. This works well in a poorly insulated house, because you probably can't afford to run the heating all the time given the energy losses. You therefore want to be able to heat the top surface of the floor quickly when the heating is on. This is the same paradigm as using radiators in poorly insulated houses - blast with heat for a couple of hours in the morning and the evening. You get fast heat-up of rooms, followed by fast cool-down as the heat escapes and is absorbed into the walls etc. With decent underslab insulation, the slab surface stays at similar temperature throughout the day, irrespective of whether the heating is on or off. In winter, our slab temp varies by a fraction of a degree over any 24 hour period. If I turned all the heating off in the middle of winter, we'd probably lose a degree a day. In short, with good insulation levels, using the structural slab as a heat buffer makes a lot of sense. I have polished concrete floors with this exact arrangement - UFH pipes in structural raft slab, and a ~65 mm screed over the original slab, with just a slip membrane (basically thick plastic sheet) between them. No issues at all. The extra concrete might even help with buffering.

This won't work in a set-up that has separate terminals for cool and heat demand (which is how mine works). You could temporarily rewire the thermostat across the cool demand terminals summer and do what you say. I don't know that I'd risk having the thermostat wired across both demand terminals. While I'm sure there's probably some sort of priority involved, simultaneously calling for heat and cooling feels like a bad idea!

Yes, this. In addition to what @JohnMo says, I imagine your radiators won't do much for cooling, so should probably be turned off during summer (remember to turn them back on before the heating season!) You'll probably need a thermstat for cooling. Most thermostats for heating applications are configured to close (i.e., switch on) when the sensed temperature is below the set point. For cooling you'll want the opposite. I think (but am not 100% sure) that some thermostats can do both. If so, there'll be three electrical terminals: common, NO (normally open) and NC (normally closed). It's possible you can do something manual - i.e., no thermostatic control - by wiring a switch, or better yet a timer, across the cooling demand terminals. Either way, hopefully whatever wiring was used for your current thermostat has at least one spare core so you can use that rather than running another wire. I suggest you post answers to JohnMo's questions and go from there.

Engineering and service manuals are available here. See this page for setting cooling mode. Midea is correct that you want to be sure that your system is correctly set up for cooling.

That's probably it. I think a lot of wild flowers very much dislike clay.

Hi Nick, just bumping this one now I have some time coming up where I might be able to take a look at this. Thanks!

We actually have a reasonable fall on the side of the roof where we had the problems: But yes, better falls to and through the scuppers would certainly help. One thing that would still concern me is the amount of crap that would end up going down the downpipes and into the soakaway. I have some screens on the outlets to catch bigger stuff to reduce this, but over the years a lot of stuff still gets through. To an extent this is an issue for all roof types, but it feels like at least some of the leaves that fall onto a pitched roof get blown off eventually, or get shot over any anti-leaf measures in the gutters.

I've told the story before, but within weeks of moving in, we woke one morning to water coming through the ceiling in our bedroom. We found found another leak in the bathroom 6-8 metres away. The weld of the membrane on two of the scuppers through a parapet wall had failed (including the one on the left in the drawing above). We'd had words with the roofing contractor over the welds when they were originally done. I thought they looked terrible but he assured us they were fine. He ended up getting out the Resitrix rep to assure us that all was good. The rep wrote a "everything done to the contractor's usual high standard" email, despite a lot of the rest of it looking like a dog's breakfast. When they came back to fix the scuppers, we made them check and replace all the others. The welds on two of those had failed too, so 4 out of 7. He assured us (and I believe him) that they'd never had this issue before. I personally think they didn't clean the scuppers properly before installing them, and there was a film of dust or whatever from storage preventing decent adhesion. Touch wood the repairs have stood up for over 9 years so far. I'd never have a flat roof again, although the real weakness is the parapet wall. Keeping the outflows clear is a massive annoyance given how many big trees we have nearby, and the difficulty of getting onto the roof.