Thorfun

well, it may have been a waste of time and money but as we paid a flat fee for our architects and the water calcs came as part of the thermal modelling package as far as I'm concerned it wasn't extra money paid but part of the fees. so no harm done either way.

that may be, but we had an architect who required calculations to be done to ensure we complied with building regs which I then sent off to building control as they wanted to see the calculations.

our water usage calculated to be more than the standard building regs but with the RWH being used for toilet flushing and garden it brought our water usage to below the BR.

I also would've failed this if it wasn't for the RWH tank. the main thing for us for the RWH was (to quote @ProDave as I don't think I could've said it any better) "prop up the failing infrastructure a bit". basically to allow those who don't or can't get water in a drought period to get it from the mains as we won't have to (as much).

the question of whether something pays for themselves has been done on here a lot and you'll get answers from both camps. personally, we plan to have all 3 of those you've listed. RWH will never pay itself back in 100s of years, but that's not why we're doing it. For solar PV the payback period could be quite a long time but, again, we're not doing it to save money or for any payback period, we want to reduce our reliance on the grid. ASHP for us just makes sense regardless of the dwindling RHI payments and requirement for MCS installation to get them as we don't have mains gas and I don't want to use tank gas or oil so electricity/ASHP is the only really viable alternative. ultimately, it's up to you and what's important to you. some on here (like me) don't do these 'eco bling' products for financial benefit, others won't do them if the sums don't add up. as I said, there are plenty of threads on this subject in each of the respective sub-forums. take a read and see what conclusions you come up with.

oh dear, I'm sat here waiting for my new Huepar to be delivered. I hope it works!

I phoned SF on yesterday and a new replacement pump was delivered today. now that's what I call service!

thanks will bookmark that until I need one. now can someone tell me the difference between a first fix and a second fix mail gun, please?

like this one? https://www.powertoolworld.co.uk/hitachi-gas-nail-gun-nr90gc2-first-fix-90mm-nailer

looks great! I'm so jealous that you're so far ahead of us in our build, but I know we'll get there at some point!

we're going the other way. we were going to have white internal timber and anthracite grey alu-clad external but after lots of thinking and looking at photos and watching lots of Building the Dream we've decided that we prefer the anthracite internally as well as externally. we love the dark windows frames internally. but we've not decided on cill colour yet. so that's another on the list of things to decide!

we've decided on Warema external blinds for our south and west facing windows and doors. our chosen window supplier (Norrsken) don't do integrated blinds and the Internorm windows we were also considering which did have integrated blinds ended up being a lot more expensive than the Norrsken and external blinds. so, might be worth considering as an alternative option to integrated blinds? as it's a new build you can ensure that the external blinds are integrated into the fabric of the building so they're hidden from view.

I don't think it's the depth of water as I'm trying to empty a swimming pool and the pump was in the deep end! I'll try the lying on it's side thing and then I'll just get a replacement from SF I think.

I think I tried that and the same outcome. I'll try again when the water I want to pump out defrosts. if it happens with 2 different hoses then I know it's the pump.

I bought a Titan one from SF and was working fine. but now it won't pump with a hose attached. it pumps if I hold it and don't attach a hose to the outlet pipe but when I attach the hose no water is pumped. would that be a broken pump or could it be a blockage in the hose? tempted to phone SF up and get a replacement.

yeah, cheers. updated calculations attached.

ok. my bad. again, I'm sure I've had these conversations before with you guys so thanks for setting me straight again. I guess my U-values aren't as good as I think they're going to be! if I remove all the external void and make the unvented one high emissivity then I get 0.137W/m2K which would correlate with @Russell griffiths calculations. looks like I'll need to get my SAP re-done then. the thermal modelling company didn't pick up on it, but I'm not surprised, they were a bit s**t.

I know we've had these conversations before but my memory is so poor that I forget everything! did that but it didn't really make much difference. again, bad memory, but I thought that the unventilated cavity was low emissivity if it wasn't a shiny surface? but again, how much of a difference does it really make?

Tanners designed a Kore system but (see other threads on this subject) I've had issues with them being able to deliver to an individual since Brexit so I've kind of dropped them for now. as such I believe the groundworks company would do as you suggest but as I'm still at the decision stage for choosing a groundworks company those details can be had once that decision has been made. thanks for the tip about 200mm sheets being cheaper. appreciated.

will do on all that. here's the detailing by Tanners showing the insulation. I'll make sure it's built to these specifications.

dunno then. I can only go on what the computer says! I think standard PIR on changeplan is 0.023W/mK but I changed that to 0.022W/mK as you can find stuff that has that thermal conductivity but if I change it to 0.023W/mK I still get a 0.126W/m2K U-value. maybe it's changeplan's calculations? or maybe it was Rockwool being conservative? or maybe they didn't include all the other bits of the wall makeup like the external battening and cladding and internal service void etc? I know there are much cleverer people than me at U-value calculations on here so maybe one of them can tell us who's right. ?

you know what? I'm going to leave that to the groundworker! they've quoted for it so, assuming I choose to go with these guys, they can do all that work and take on the responsibility for not messing up the calculations.

sadly we need EPS300, specified by Tanners. thanks for the tip.

I did the calculations myself using changeplan.co.uk. that's Frametherm32 between the studs and 0.22W/mK PIR on top of that. works out to 0.12W/m2K