Nickfromwales

Heat recovery all winter?!?! Why bother making an airtight house if you don't intend to install MVHR? Why bother installing it if you don't use it? And how the feck does anyone expect to get a sign-off from the BCO if you haven't installed mechanical extractor fans in each bathroom / utility / kitchen whilst you think it over? In rainy seasons you'll be importing humid / damp air and this will be trapped within the fabric of your build when you do finally shut up shop to go to sleep. Open windows all day every day and whenever in-between, but, when you close the house up, MVHR will come into its own.

30mm of PIR insulation and then 18mm of P5 boards over the insulation screwed down to the floorboard level, with 3.6mm plywood over the P5 as a binder? How much insulation is under the existing floorboards? Have you sealed up with foam yet to nuke all the drafts?

Great choice with MBC, and please stop panicking about UFH in the slab! I've done loads with MBC / Kore etc with the pipes in there and not a sign of trouble anywhere, other than where I expected it (hairline cracks between ring beam and intermediate beams) and where we managed this by planning / design. The good thing with MBC is they are happy to oblige with penetrations in steel etc for the M&E side of things, and I work well with them to make the 1st fixes dead easy (ergo cheaper and quicker) for things like foul & waste water + MVHR. Had some exceptionally good AT results with their PH offering too, so I am sure you'll be happy . Listen to your SE btw..... Most stuff is already hugely over-spec'd / over-engineered, and if they're telling you to relax you should listen as that = ££££££ if you don't. Grade the hardcore from the demo and reuse on site too, that's what I'm doing on a replacement dwelling project (coincidentally also in Surrey!) which will save a load of money with the crane pad and temporary access roads. Let me know when you get cracking (and, more importantly, when you have a kettle set up) and I'll swing by to see how you're getting on.

Defo isolate the immersion and try for 2 weeks. Cheapest, simplest route afaic.

Ultra / Mapei / Bal etc are all fine and usually on the shelf in most decent outlets. Been installing bathrooms for over 30 years with all of them, never missed a beat . My 2 cents, do not use silicone for fundamental sealing, just use it as a cosmetic seal; I don't EVER use silicone to seal trays before tiling, instead use CT1 as it is a completely different product without the short service life that silicone(s) tend to have.

You can get Shelly’s with a LAN connection (RJ45 socket).

Any sentence with “the government” as any part of it is fecked from definition, so don’t hold your breath. Why are FiT entitled ‘customers’ still getting FiT payments for the next 20 years or so, way beyond the capital cost of having the system installed?!?!? Yet a young couple wanting to do the right thing and ‘go green’ don’t ever see that money, which sends FiT entitled masses on holidays and the such. Ffs. “The government”……suck, at much of what they do tbf. Why should this abortion of a scheme be any different? 🤷‍♂️

Would also be wonderful to know how many of those were caused by installer error / poor workmanship.

It’ll need to be designed as fit for purpose via an MCS installer / software. MCS ensures a safe installation, so dictates things such as this eg fixings et-al. Not sure where DIY begins / ends if part of the fabric of a dwelling (in-roof) and build warranty etc. Do your checks before writing any cheques.

Can you upload a sketch? Just a hand drawn sketch on a bit of A4 will do You should stay away from the perimeter by about 100-200mm, which will allow you to form long radius bends in plastic pipe (I favour Hep2o) to go around obstacles, and then when you need to rise vertically out of the insulation you just dig down and sweep the bend which avoids too tight a radius. Sleeve the pipe where it rises out of the insulation and through screed(?) so the pipe can have some movement.

On grant work, iirc, my trades are getting around £1k per ASHP install, electrics / controls / commissioning etc. £1850 is taking the piss. We're in Gravenhill atm, if you are completely stuck let me know by PM and I'll give you my guys details.

100%. It’ll be a huge regret for the OP to follow the proposed route. 👎

Only if you want zero warranty. They'll just say "non-standard installation" when you attempt to claim. They did that to 2 clients who claimed for failed units, ironically they did the design on one lol. As far as zero annual maintenance, these have expansion vessels, so those need to be regularly checked and maintained on a Sunamp / Thermino / Aquafficient, or again....no warranty. You need to drain down, test the pre-charge pressure, and then fill back up again. At the current prices for these things, installed, you (and the salty box), would need to outlive your great grandchildren.

Yup. Need a packed lunch to go from the basement to the top floor lol.

If you're really after belt & braces, fix some vertical sections of 4x2 to the masonry wall, and strap between the stud wall and those with 2 x 4x2's. Locate them height-wise at the top of the frame to remove any 'wiggle', but tbh you're setup is similar to how I install for clients (and nobody has 'bottomed out' yet lol).

Does anyone have any links to the statistics on domestic battery fires? AFAIK there's more chance of the tumble drier going up in flames than a 'solar' battery Put it outdoors in a second 'kiosk', adjacent to the one doing the mains? Metal-clad if possible. Mine will go in the shed / outbuilding, as is my plan for my current clients project; (20kW battery per phase / 3ph + ~16kWp of solar). I've not just looked at risk mitigation for this myself / my client(s) as the kit is sizeable too, so I'd prefer not to lose any of the GIA of the actual dwelling either so will mount / locate remotely. Cables will be oversized from outbuilding > boundary kiosk > dwelling accordingly to minimise voltage drop to the nth degree, as a 35mm2 cable isn't lifechanging sums more than a 25mm2 plus leaves room for 'more' if downstream bulking of battery system is deemed advantageous (~1900m2 residence with indoor swimming pool, sauna / steam-room et-al). I'm putting a guesstimated size system in and will recommend running the home for 12 months to gather statistics, so will always consider a structured battery / solar setup that can grow. I dislike the notion of sizing to take advantage of a particular electricity providers 'offering of the day', seems too risky for me to spend a clients money on (I have responsibilities as the Main Contractor and consultant, so my 'ideas' need to be robust before I convert them into an actual recommendation). I prefer knowns, so work on solar capture and look to store and utilise this pragmatically. IF a favourable provider / tariff then comes along downstream we can add that to the mix to maximise RoI, vs rely on it. @Russell griffiths, defo have the batteries as you and Mrs G work from home, just put them outdoors if you're that worried. Simples.

OK. I think you should have more loops / zones. If I was designing this as' your M&E guy', I'd have a loop per space. The bathroom should be at 100mm o/c and be as fully populated as is practicable. Space A-01 should be fed by taking the loops under the wall. Space A-02 is fine. A-07 should also be at 100mm o/c as it is a rising space to FF. Consider the effects of the days solar gain, and how it will affect each space. IMHO, the current design does not. You have some small, confined spaces, which will 'out-perform' the other, larger open areas.

Go for a horizontal UVC and put everything else above it?

In a "passive house" the flow temps are inconsequential. I now pipe under every single shower tray for my clients builds, staying around 400mm away from the waste / drain. Why? Not sure, but I am reasonably sure confident that it's entirely moot tbh.

You can't do any harm, so just work out what the lowest setting is that will maintain the room temps. Biggest question you should be asking right now, is what temp to set the mixing valve to Start off at 40oC and go up each day in 2oC increments until you are happy. Don't make adjustments in the same 24hr period, patience will pay dividends here

Members can petition @Andrew Jones directly via PM, please feel free to do so.

Don’t cry. There are people you can talk to

You won’t have excess solar when it’s wintertime though. Plus, trying to operate a heat pump on sporadic pockets of sunshine is just barking mad.

Plus MVHR?