jack

We seriously considered having one in our house, possibly set up as a bar. Hard to justify the cost at the time though...

I looked into all of this when I was planning what to put on our roof, and solar thermal just made no financial sense for my circumstances (admittedly helped by getting into the FiTs scheme just before the rate dropped to almost nothing). I'd encourage people to do their own sums.

Just state that you're one-track minded about solar thermal and leave it at that please.

Exactly. Our architect hadn't worked with MBC before we used him, so he contacted them to get the wall buildup details he needed. He hadn't previously used the windows we specced , so he contacted the manufacturer for their recommended installation details and discussed how best to position the windows within the actual wall buildup being used. Why, in this case, has an architect who clearly hasn't used a system before made assumptions (and poor ones at that) rather than seeking input from the SIPs supplier?

But if you do both, you're paying for two complete sets of infrastructure, with increased complexity of control systems, increased maintenance costs, and increased risk of something going wrong. I think you're better just sticking to one technology.

Ditto. My poor electrician was given 10 mins to install a protective steel plate over a cable for a floorbox before a concrete screed layer (to be polished) was poured. He put in four screws, and the drilling for two of them went straight through a UFH pipe. We didn't find out for something like 6 months, when we woke up to find the floorbox full of water and a puddle just starting to spread from the centre of the room towards the walls! Dug it out and used two straight couplings to patch in a loop of spare UFH pipe.

This isn't my experience. We have UFH downstairs and no at all heating upstairs. The upstairs is very noticeably cooler in winter, despite us having a very large stair opening and several square metres of double height area above the kitchen. My theory is that, in a well insulated house, the floor temp required to maintain a comfortable temperature downstairs isn't enough to cause convection currents that would bring the heat upstairs (naturally some makes it up, or upstairs would be freezing).

The outgoing drainwater (typically mid 30s deg C, I guess, for a typical shower) is used to preheat the incoming cold water during the shower. You can also connect it up so that it also preheats water supplied into the hot water tank/combi. This arrangement has the highest efficiency - they claim up to mid 60s% efficiency IIRC. Edited to add link to explanation of different connection possibilities: https://recoupwwhrs.co.uk/installation/installation-methods/ I think it was the largest Recoup model (Pipe+HE, from memory, but it's been a while!)

Yes, we have one that's connected to our ensuite and main bathroom showers. Easy enough to install if you're building from scratch or completely gutting a house. Retrofitting is harder, but there are options for fitting, eg, underneath shower trays. They aren't a quick payback, but you can go for a slightly smaller hot water tank, plus I don't see anything wrong with a product that lets us use less energy for a couple of decades, with little to no maintenance.

Have a look at shower waste water heat recovery units. Good for a few SAP points, only a few hundred quid, and will make your hot water last longer.

It's quicker and therefore cheaper if you don't have to cut boards. You can get 2700mm plasterboard though - easy enough to cut off 100mm, although why not go for 2700mm high ceilings if your rooms are big enough to handle it? As for whether it's worth doing the extra height, I personally think a bit of extra height helps, especially in larger rooms. We have 2850 ceilings downstairs and I think it makes things feel very spacious.

Welcome. With a name like that, I hope you're following the gut microbiome/low carb thread

Your body temperature starts falling in the evenings - that probably has an effect:

While weather forecasting is still not perfect, gross estimates about upcoming air temperature are usually reasonably reliable. You don't need to know whether it's going to be exactly 10 or 12 degrees - just knowing that it's going to be (for example) a lot cooler for a few days starting tomorrow is probably sufficient to get you 80% of the way there for predictive heating. It may be more complicated if you have a lot of solar gain I suppose - it might be cool air temps but lots of sun, for example. Not an issue I have to contend with in our house, with its relatively low solar gain! That said, our house temp has dropped below 20 degrees in the last couple of days. It's still comfortable enough that I can't be bothered turning the heating back on.

Had a quick look and it seems Pazen went bust due to the bankruptcy of two suppliers. A real shame - it was a family business run by some really nice people (we visited them before ordering). I see Enersign bought the business, but are you sure that Enersign only supplies these windows and not others as well? That said, the brochure looks like the Pazen brochures, although it's been a while since I've seen ours. Certainly the ENERstore blinds on page 6 of the brochure above look like what we have. This was one of the major selling points for us, but I'm not sure I'd make this choice if I were doing it again. While this detail looks nice from the outside, when looking out from the inside the view is curtailed by the external reveal being in line with the frame. Naturally this is worse with the deep external reveals you get with the thick walls used in highly insulated houses. You also need cladding contractors who are meticulous about lining up the the reveal with the frame. We didn't notice until it was too late, but our contractor (the second - we fired the first) was pretty relaxed, and different amounts of the frame is visible from window to window. Bear in mind also that you still see the frame even if it's completely behind the cladding, because the depth of the frame is still visible. It's much more noticeable in light cladding (we have white painted brickwork in some areas). One reason was the concealed frame detail mentioned above. Another was that I was hearing very mixed reports about Internorm installations even back then, plus the quotes we got from Internorm were no cheaper than Pazen. We had trouble getting quotes from another supplier I was interested in using (can't remember who that was now). It came down to Pazen and Gaulhofer in the end. Interestingly, we were put off Gaulhofer when I showed their local agent Tomas (who sadly passed away a few months ago - see thread elsewhere) our drawings when I met him at Ecobuild. I had a really interesting chat with Tomas, who made some useful points about detailing and installation. He also took one look at the elevations and said that they couldn't supply some of the windows as single tilt-and-turn, because they were too heavy even for the heaviest duty hinges. I therefore foolishly didn't end up getting Gaulhofer to quote. When we visited Pazen right before signing off the deal, the owner/MD spent quite a lot of time going through all of the technical drawings with our architect (he's a mate of ours, so we splurged on a £50 return ticket to bring him along!) As soon as he got the big windows at the front he pointed out they couldn't do them, just like Tomas had! By this stage it was far too late to start considering Gaulhofer, so we just bit the bullet. I suspect this cost us many thousands of quid. The Pazen windows are very good quality. In fact, a passivhaus specialist I met described them as "the Rolls Royce" of alu-clad windows. Unfortunately, we were let down badly by the installers, as catalogued repeatedly on BuildHub. If I were doing this all again, the main thing I'd be looking at other than window quality and price is making a billion percent certain that installation would be done by the supplier in accordance with installation details agreed up front.

Same here. Bigger windows, in general, stay open better, but really tall ones can struggle because the inward tilt (which is fixed irrespective of window size) doesn't put the centre of mass of the window far over the pivot point.

There are all sorts of subtle ways of implementing summer bypass modes, but in general, the heat exchanger should be in the loop at all times, except when the interior temp is too high and the exterior temp is lower than the interior temp.

But the genvex still operates the heat exchanger unless it's in summer bypass mode. The OP seems to be talking about bypassing the heat exchanger when the air con is operating. Generally that's exactly when you'd want the heat exchanger to be in the loop.

I don't quite follow this. Air conditioning is a closed system, so it doesn't cause "draw in" fresh air from the outside. You therefore still need to run the MVHR when you have the aircon running, otherwise you'll have no fresh air coming into the house. If you bypass the MVHR heat exchanger and draw in the air from outside for supply via the MVHR ducts, it still needs to leave somehow. Perhaps you're planning to use positive pressure provided by aircon, and to have that pressure cause air to leave via the extracts? Seems a potentially very wasteful arrangement if the MVHR heat exchanger is bypassed. I also think you'd need to carefully consider how you'd provide the cooled air at enough pressure to force it through the ducts - a standard ducted aircon system relies on much larger ducts than used in a typical MVHR system. Am I missing something? Perhaps a diagram would be useful.

You can still hear people/cars on the angular stuff (we have it), but you don't have to keep raking it around like the round stuff!

I think we figured out that the shutters were the z profile from Hunter Douglas. Control is by Loxone, which also takes care of lighting.

We're just outside the Thames Basin SPA - close enough that it had me a bit worried about the potential impact on planning until I looked into it a bit more closely!

That's exactly us! Thanks for the link.

Your guess is wrong. The last point we got to was them agreeing to take off the charge, but we had to prove the water was now going to a soakaway rather than the sewer. It wasn't at the top of our list at the time and it's fallen off my radar due to everything else in the meantime, but I'll get back onto it shortly.

I'm interested in this, as I believe we pay a specific component for surface drainage despite now having a soakaway (house we knocked down had downpipes connected to the sewer). We did start a conversation with our water supplier a while ago but I completely forgot to take it back up again!