Nickfromwales

Ah, gotcha. I just recall it discussed in quite fine detail the values of the different insulation types, and included mineral wool in one example, wood fibre in another, and PIR at the outset. One would assume all types are ‘useful’ but the option to fit PIR snugly vs compressing mineral wool in had good arguments for them either way, with the conclusion that convection airflow through any material (including ill fitting PIR) would virtually obliterate any gains from thickness / type. Seems methodology reigns supreme here, so great results come from finite detailing and meticulous execution of the membrane installation methinks. I just thought that thread covered this more comprehensively.

Something like this is nice too. Well, nice except those scabby bricks on the walls lol 🤢🤮

To be honest, I’ve never had a duff one other than from B&Q, one of their 1800mm long ones with the glass dividers, walk in type things which bellied up in the middle and made a lovely pond. I used to buy off eBay all the time, usually the same stuff the merchants gave out, and was always cheaper. Mira is a nice tray, good all round d daily driver, so if you’re not on your uppers then grab 2 of those. I fitted 2 on a job in Oxford and they had a nice linear drain at the end. Was nice to not be stepping on the drain cover.

Have you browsed yet?

It says the supply isn’t as bad as some I’ve seen, and pressure is good, so l/p/m needs improving which should come with the new mains pipe. Will you ask for a new stopcock in the street so you’re as good as can be, or will you DIY and connect to the existing at your boundary?

How big is your chuffing house? Are you willing to adopt?

It’ll do that until the system acclimatises and ‘cools down’, the question will be is how low can you set it to still maintain room temps / not take an age to heat back up from start. Leave it set lower and allow it some time to stop it complaining.

Yup. I'll often dig up the mains at the boundary and test there, to discount a damaged or 'furred up' pipe between the network and the stopcock (within the boundary). People have replaced the cold mains and saw little to no improvement.

I thought I'd stage the delivery of all the negatives, lol. You know, just allow them time to have a cup of tea and a Valium in between etc.

+1.

Nope. A doddle, as we just programmed the roofer and let him crack on lol. Very simple to do tbh, just time and labour / materials, nothing overly technical or complicated to it.

My point was more about the inconvenience of all this when the house IS occupied, eg having to open bedroom doors and windows etc when someone is snoozing on a Saturday morning for eg. It's just something I dislike, even in PHPP; one example is where I just agreed a new approach with a PH certified architect & (our) client after he had already proposed an M&E solution directly to, without my knowledge, and then I objected due to many of the inconsideration's it assumed the clients would 'live with'. These contained many days of the year where the dwelling would routinely achieve internal temps at >25oC (an infinity symbol was conveniently inserted in that box iirc) and would require E/W purge 'cross-ventilation' pathways from ground floor to 1st floor....tidy.....and many other days where auxiliary heating would be required during the winter (eventual admission was that the client would have to roll out oil filled rads and moderate their output per room / space to prevent overheating!). Joy! It's only when you get someone who knows these things inside and out, form all perspectives, do you seem to ever stand a chance of "getting it right", especially as a layman or novice self builder. I've often become quite fed up of babysitting 'qualified' people when working for many self build clients over the years who say they "do this as part of their day-to-day routine", but soon are demonstrating comprehensively, just how incomprehensive their approach actually is. Sometimes it's just downright scary how highly regarded these people become, with not very much good reason. Each instance requires a fresh approach, so it's difficult to pin a tail on any one donkey here, but happy to provide answers to any specific questions, if that's of help . Not necessarily. I objected, as above, and presented a new MVHR / heating / cooling strategy, and subsequently got an outcome 1% higher in efficiency than the PH certified architect (which is a big amount apparently). That was just from asking proper questions of the client(s) and knowing how to best provide practical solutions to create a comfortable home for someone to practically live in it. All to often the focus is on the pinnacle of a dwelling in the eyes of the designer, with little regard for the people who may then be trapped inside...

I'm saying it absolutely doesn't factor sufficiently for each individual circumstance, it's a blanket policy at best. Building regs are, and will likely always be, the worst standard you can legally build to.

None of that should really matter, so it's odd behaviour tbh. Do you have a non return (double check) valve immediately after the stopcock? Defo pump the EV pre-charge back up asap. That's how I would have left this from the point of commissioning, before leaving the property tbf. Don't forget the NRV on the hot outlet of the UVC, but my advice, with the less than cosmic local network flow / pressure you have, would be to use a 28mm NRV with 22mm internal reducing sets; so there is little to no resistance from the bigger valve body .

We put them on the roof routinely now, as mounting them remotely seems to conflict with MCS ‘good practices’ if adding made up ‘jumper cables’. Note the silver boxes (optimisers) at each tray.

I disagree completely. B Regs are bad on a good day, if you work to them then prepare to fail. lol.

Fitting an ASHP for UFH and DHW (domestic hot water) is an absolute no brainer. If the house is going to be built airtight (sub 1.0ACH minimum) and MVHR is included in the overall M&E spec, then the heating requirements should be very low anyways. ASHP + UFH with cooling via the ground floor slab must be considered for full time occupation of the dwelling To not do this now will come back and bite you on the ar@e I assure you. Very likely the WBS will be lit a few times and you’ll then soon become overwhelmed by the amount of localised heat from it, the biggest issue being it’ll be a well insulated and airtight house; MVHR will not move the heat out of the room as fast as it’s being produced, so hopefully nobody has suggested it would ‘distribute’ heat through the home. For the times the dwelling is unoccupied the system will just mothball itself. You’d set the room stat to say 17°C, for eg, and unless the house gets that cold the heating won’t come on. Same for DHW, it’ll just do an automatic anti-legionnaire purge every 7 days. If there’s PV (ground mounted can be facing due south(?) or East/ West split) then you’ll very likely have no associated running costs when unoccupied (when calculated over the year). Better again if there’s a battery, but I’d probably not bother with that until the 7 years are up. Just set the purge to happen at midday and let the PV cover that. Have you calculated the cooling requirements, for when the house is used routinely and you get a series of very hot days back to back? Part O compliance etc. If you have an ASHP that can cool you can then practically remove a lot of that problem heat, whereas without it you’d be left with manually purging the property; achieved by strategically opening doors and windows which would be more of a PITA than you think. It would need to be done all the way from very early morning until into the late evenings, EVERY SINGLE DAY, and if the outside temp is high the cooling effect is minimal at best. Personally I hate being over 21°C, and at 22+ I want to kill. Do not compare doing this in a current, draughty, poor standard house vs this new house, as they’ll be chalk and cheese. Very different world that you’re stepping into, but very nice when designed, and thought out properly. You say you don’t want to spend money on something you say you’ll “hardly ever use”, and I think that statement is based on naivety, sorry, and would be the worst decision you make. A tiled floor that is unheated will definitely feel colder under bare feet, but that’s simple to avoid with wood or LVT, but in honesty if you’re in a house of this type and the UFH is on, your (tiled) floors would not feel ‘heated’ to the touch; your skin / body temp would not be far enough away from the surface temp to make this notable. To achieve a room temp of 21°C (which is very warm in this type of house) would require a floor temp of possibly 24/25° (max, in depth of winter) but likely less when considering occupants, appliances and solar gains etc. The ASHP would barely be doing much at all to provide that background heat, and for most of the year you’d be doing PV > DHW for next to nothing and setting it to heat off cheap rate overnight during winter. The ASHP can also be used to send heated or cooked water to the ventilation (MVHR) to further improve things, which adds a bit more ‘climate control’ or to a fan coil unit for bulk localised cooling (hall / stairs / landing etc). Lots of options but each situation is feasibly unique, yours inclusive as it’s N/E facing and you’re coastal. All this will absolutely “be used” so I think you need a rethink Members on here have built to passivhaus standards and beyond, and still report needing at least some heating during winter quote “to avoid divorce”, but most have either designed in cooling (via slab & UFH or with fan-coil units) or were forced to retrospectively install an A2A system (air con) for the summers. Simple’s, eh?

Check out https://www.pavingexpert.com 👍

You can have a recessed manhole which accepts the finished product. 👍.

I would pump this back up to 2.5 to stop damage occurring. It was incorrect for this to have been dropped back so far imho.

👇 👍 Rely on that taps NRV at your peril. I wouldn’t! If this was a clients project there would be no chance I’d leave it like that. My shower mixer had these and I shut the cold inlet off to my combi the other day to work on it and water kept coming out of the hot tap at the sink. When I listened to the shower you could hear water squeezing back through the hot NRV so I then had to turn the temp dial to max cold to stop it enough for me to do what I needed to, but it goes to show that these factory ones are pretty crap, even with such a good make as you’ve selected. Noise issue you are experiencing is defo the EV acting as an accumulator, and very likely the issue will go when you have a better supply installed. The washing machine etc would be best off the cold mains if practicable, which will give the showers better dynamic performance if the appliances are filling simultaneously for eg. I have a combi so the rule here is if you hear the shower going don’t run taps full blast. Flow just speeds up or slows down with an UVC but with a combi these fluctuations cause havoc (aka entertainment). Anything you can do to improve that is a plus, if doable.

Thanks for updating the thread, much appreciated.

Like...."who's coat is that jacket?" Welcome, and fire away. 👍

☝️? Or another?

Ok, as is you are compliant. If, however, you do install a new tap (which mixes in the body) then you aren't. That would need the second PRedV at the stopcock and the NRV on the hot outlet of the UVC. Easy going plumbers will tell you it's fine to rely on an added non return valve on the kitchen tap hot feed, but it's just not reliable enough. These start to let-by after a while and then the UVC will get reverse pressurised by the cold pressure at the kitchen sink mixing with the lower pressure hot, and this is particularly problematic when the tap is run on low flow for a decent amount of time. This should have the 2 items, PRedV #2, and a NRV on the UVC hot outlet, to be fully compliant (and to not come back and bite you on the arse in the future). Without these, the UVC expansion vessel will routinely get over pressurised and fail early. You chaps are spot on, if they knew the kitchen sink tap was for unbalanced, but they should have assumed that would be changed one day and have gone the extra distance (IMHO). So they get a 9/10 lol, for not getting the kitchen sink fed off the balanced cold.