G and J

Yet. If everyone harvested rainwater then the % charged of the input water would no longer pay for our sewage system. Anyone fancy inventing a poo-o-meter that measures household output? Might make your millions if you patent it.

I started reading about rain harvesting and two things hit me: even allowing for the sewage % thingy our water bills are so reasonable that payback looks unlikely; secondly the sheer tonnage of plastic involved made me feel that such laudable sounding aims might not turn out to be any kinder to our planet, maybe actually worse.

OK, potentially a dumb question. What does a solar survey determine?

It seems that most folk expect a build done by a builder for a client will come in circa £3.5k. It’s tempting to infer from the above that materials cost is around 25% to 30% of the build cost, vs 70% to 75% of the build cost being labour. Staggering!

Thank you @Nick Laslett (oooh look at me getting all technical!) - added to the reading list. I presume from the existence of airtight OSB that standard OSB isn’t airtight then?

One thing I’ve never liked about backboxes for plasterboard is that they become loose when the face plate is unscrewed. Even if fitted before skimming this can happen and it makes a mess. It did occur to me that the OSB layer may enable me to fix metal backboxes by screwing through side walls into the OSB to avoid that issue.

Noted. Would love to understand the reasoning. Presumably you mean my service void studs rather than the main frame studs. Mind you, I’d love to do the frame on 1200mm centres, it does wonders for the u value.

Earlier this week I visited Nick Laslett’s build and he was very generous with his time and patient with my myriad questions. And as a bonus I now feel I’m not the only Makita obsessed diy-er. I also realised it has never occurred to me that there may be alternatives to plasterboard other than plaster on blockwork. How dumb do I get? (No replies on that subject needed, thank you!) Because I’m mildly neurotic, occasionally obsessive and always annoying, and because we have a narrow plot that we want to make the most of we are trying to build with relatively thin walls. I also like the idea that we could hang pictures and mirrors and stuff anywhere, so I’d focussed on an internal skin of OSB or ply inside my plasterboard. We have a possibly irrational preference for skimmed walls as well. The benefits of the wood layer beneath the plasterboard are feeling of solidity, maybe a bit better sound attenuation (from outside, internal sound transmission is less of a concern), and of course the ability to hang stuff on the walls. Nick is using fermacell and he mentioned that habito might also be worth a look. So after visiting Nick I read all I could find on here about each of those. Are there other types of board I should consider? It looks to me like the materials cost is not all that different, and if so, the driver will be optimising the ‘feel’ of our little house. What do you think folks?

Aren’t Vincent Timber not so very far from you? A lot deliver almost nationally I think.

Presumably you still had to get the install signed off by a G3 person…..?

Hmmm, true, but would it be better to accept that the tide is coming in and rather than one of each type system just pressurise the lot and go with current bog standard….?

I get the electric towel rail. But the doubling up on the UFH seems daft to me, even if the COP is poor when heating just the bathrooms it won’t be less than 1, and it can’t be hard to have a second zone for just the three bathrooms and as you say, at certain times of year, courtesy of the MVHR that’ll do the whole house. And that’s the woodburner…

Well, I do think going with a personal preference, all other things being nearly equal, is valid, so that’s a biggie for me. There is some history here. In ‘91 I fitted a gravity (much nicer term than vented) system with an oil boiler that’s still going. In 33 years (touch wood) I’ve had to replace one valve, the ball valve in the loft as it got noisy. Easy peasy. I’ve also had installed various pressurised (much more honest term than unvented, I prefer to call a spade a flippin shovel) systems in various properties that have had to have regular professional involvement. Downtime, guest/tenant angst, cost, hassle. OK that’s all been gas boiler based and maybe it’s not representative of the likely experience in our new pad, but it’s still my backdrop. I’m also aware that I don’t have as much irritating and pointless box ticking with gravity systems. Sigh.

So if I have an ASHP and I want to benefit from a warranty I have no choice. Sod. At the start of this thread I asked “Am I missing something glaringly b obvious…” I now know the answer to that one lol

When I bath (I am a hippo!) I leave little hot water. When J showers (she very definitely is not a hippo!) it leaves loads of hot water, so I’m designing around my bad habits lol

Ummm, so do all heat pumps require unvented? In my infinite stupidity I see no reason why they would.

Noted. Thank you.

May I ask why that rather than other systems?

Sorry JohnMo, I don’t understand what that means. We are thinking along the same lines, for the same reason we’ve put an electric towel rail in our en-suite so it’s warm when the heating isn’t needed. J loves warm, soft towels. Do either of you have a very eco-unfriendly bath habit? I know I do.

Just googled it - so it’s the same system one uses for wet underfloor heating it appears. Interesting economy of scale if using the same tools and pipe for both….

Sorry to be dumb but presumably a Thermal Store is different in some way to a hot water cylinder?

So you are effectively saying that UV is dead simple to maintain?

Interesting how similar our thinking is…. 1. A 5kW monoblock ASHP. TICK! 2. A 300l ASHP UVC. I was thinking 300l ish, but vented. I believe they exist. 3. Hep20 push fit plumbing with the hot manifold preheated by convection above the cylinder. Pipes run in a radial fashion. 15mm for the baths, showers, and kitchen sink and 10mm for everything else. I’ve plumbed with Hep20 successfully before, and I’m happy to do so again - my plan is to work it so that no joints are buried - will be mostly radial. Pipe size perhaps depends on whether I go vented. 3. In slab wet UFH in a single zone downstairs. TICK 4. Electric UFH in all bathrooms. Ah, we’re thinking wet UFH in upstairs bathrooms. 5. Floor drains with waterless traps in every wet room for leak protection. Haven’t thought about this but yet.

Back in ‘91 I plumbed our house. Oil boiler in garage, hot water cylinder in airing cupboard, steel rads in most rooms, two tanks (little and large) in the loft. Showers have about 6’ head, and are fed by 22mm both hot and cold the cold being direct from loft tank to balance the pressures. They still work well, so assuming Aqualisa make similar I’ll be replicating as yes, I want to go vented. That way I can install and maintain, I’ve space in the right place in me loft and I do like simple. I (or someone) will be putting in an ASHP which will run the UFH and DHW. I might go a bit space age and fit a stirry up pump thingy, as I think that effectively increases the hot water capacity of a system, I’ll look into that in due course. One thing I’d improve (meaning reduce) if I could on my current system is the amount of water drawn to get hot water to each bathroom. I foolishly did some of the DHW distribution in 22mm copper and the rest in 15mm. Another thing I would improve is having no buried joints. I have dozens of solder joints buried in floors, etc. so the idea of using manifolds and continuous plastic pipes so every joint remains accessible appeals. I’ve read just about all I could find on here re vented vs unvented and I remain convinced that I like vented. I note however that the world quietly went unvented over the last three decades. First question. Am I missing something glaringly b obvious in concluding vented is ok for my new house?

I built this housey on sauuuuuuu saaaage rollllllllls… But I’m guessing I need a good rodent barrier. (With apologies to LadBaby!) I'm really appreciative of all the inputs guys, I think I need to reflect and revisit this soon.