Nickfromwales

You could have "normal" sized windows in a certified PH, and apply solar reflective coating to manage that. The PH architect would likely push back, but so would then I. Sense would of course prevail.....

Indeed. Set a laser up each end and see if the line stays at the centre of each run. That's a quick way to see if you'll meander off course with fixings. Also needs a map making to avoid the few obstacles. Take LOTS of pics with tape measure in the shot

I assume you're using 2x1 battens over the PIR? Or what is your plan for electrics to lights? Above insulation and dropped down / through? Penny washers and the PIR will be ample to hold the wool at bay, just use a couple more and sleep well. May be a good idea to foil tape the joins and foam the perimeter, to stop the fibres entering the air in that room. Not the nicest of stuff to have continuously feeding into the room.

The one we did in Oxford was stop-beaded, plastered, painted and so on. Bathrooms in and done, kitchen fitted, M&E complete, and THEN the happy polish guy turned up with a van-load of pre-made & swung units. A couple of days and they were done, zero issue. You can design out any problem These guys slept on site, using packs of acoustic Rockwool as mattresses . That's what you call 'saving your digs money', but on a whole new level.

The threat of death works wonders. That or taking their mobile off them.

Add a strip of 11mm OSB to the beams, then plasterboard? Or stick with 13mm. At 35mm and within the heated envelope means this is neither here nor there tbh, just make sure you fully fill the voids where the pipes exit up high, to stop convection losses from the room to the attic. After that, I think you can relax.

Be careful……you’ll hurt Persimmon’s feelings. 😂 @Thorfun can take it. Lol. Board over the large openings first, then keep the off-cuts for use elsewhere

I only use 9mm or 13mm in PH settings (9 on cold water and 13 on ‘hot’ heating / UFH) but I always use 25mm wall for DHW and DHW HRC. The grey stuff is cheap as chips so just fit 19mm and be above the standards. Remember that part L is a dogshit standard and nothing to ever be bragging about, hence the recommendation to go “overboard”. Once you’re at the price point of 9mm or 13mm, you may as well go to 19mm. I’ve been looking into insulation for my current Passiv Haus project (as PH standard has just tightened its belt also) and there’s extremely little in it between the black neoprene (Armafalex / Armacell) stuff and the grey (Climaflex ) stuff, to the point that for the significant cost difference it makes better sense to me to go one size thicker and stay with Climaflex. For DHW and DHW HRC runs I’ll stick to 25mm wall Climaflex and tape along the seams with the Armacell 3mm x 50mm adhesive ‘insulation tape’ for belt & braces.

I'm on a job where the clients went "Amazon" for the irrigation and it hasn't gone too well. The spurs with the outlets on them all pop off so you lose the spray effect. I expect this could be managed with a pressure reducing valve, so maybe prepare to install one of those onto 2 flexis and then put that inline. Having raw cold mains pressure going into these is not a good idea Same as everything else, buy cheap buy twice.

That's plenty. 1:40 - 1:60 is max / min, but as long as it's downhill the BCO won't care....plus the fact that a 50mm pipe creates its own air-break means the water can discharge down the pipe at its own pace without affecting the rate that soap suds etc disappear down the shower drain.

Your plumbing has come along nicely, our young apprentice Looks good to me, just hard to see the actual fall of the long run? Have you put a laser / level on it end-to-end?

Exacta Mundo. 👌 A pattern develops....

It's horses for courses, simple as that. Private clientele who know zero about construction would be forced to use a PM. Not all PM's are any good. That cost is a set % of the gross build (project total) cost and can be utterly unfair and disproportionate, and can also be a 'risk'. That can be a 5 to 6-figure sum. With a company which provides a turnkey service (foundation, structure, insulation, airtightness, B-Regs, S.E. etc) there is an inbuilt opportunity, should you have chosen as well as is practicable, to save a huge chunk of the PM fees that would otherwise reside in your lap, be your responsibility, and would be utterly uninsurable against (most architects and PM's have a long list of exclusions and caveats stitched into their contracts to limit their liabilities) so the risk doesn't go away even if you It's down to trust, getting a "feel" for the customers or companies (the shoe goes onto either foot) and then you decide which is the better of the "2 evils". MBC is like a family run business, and they don't stray from what they excel at doing. They have a 'get in, get done, finish, move onto the next one' ethos, and I for one hold them in very high regard. Would I trust them with £100k of my own money? Yes. Would I trust them with the same sum of money if that relied on them having successfully imported a finished product from abroad to then pass on to me? No. The reason is, trust wouldn't be relevant, as there would be the additional weak link, a completely unknown 3rd party risk attached, a-la the Isotex debacle; a set of circumstances which would then be something that changes things way beyond my comfort zone. These are my own thoughts, and opinions, and not advice. But they do come from over 8 years of familiarity.

It does make a difference, even for a short run. Up to you what you want to do, but I say things for good reasons

It’s single wall pipe, vs the multi-layer. All ‘fit for purpose’ but if I posted you an off cut of the other you’d immediately see the difference. The bottom line is, this will be 10 bar capable and rarely see more than 1.5-2. I’d say you can sleep soundly tbh.

What is the silver valve on the hot outlet? Is it an isolation valve? Pic?

You can see those, clearly, I’ve already looked at the pics closely. OP says they want to limp by, but they should t really be using this appliance as it’s (the gas burning appliance) not been installed to the manufacturers guidelines.

Get the electric immersion on, and turn the gas off. Better to be safe than sorry.

The pipe in that pic is of Pert pipe, so basically like a garden hose. I use Pex-Al which has an aluminium liner and is tough as old boots.

Yup, if you’re not comfortable with repairing it without your plumber? Short cuts typically create 3x as much work, so just pull it out, sooty the pain with beer, and thank yourself afterwards.

This is the actual job. Those couple of pics show the aerated kicker blocks with the blue Marmox atop, and then the 2x soleplates sat directly onto the Marmox. I’ll see if I can sketch out the AT detail.

Offer them £200, and a link to the other one!!

Indeed. People’s spend with MBC are quite significant as they do foundation and frame packages, so the £12k insurance (or an uplift of £6k vs the other routes) seems to me to be ‘not insane’. MBC are spitting out houses at a fantastic rate, so I doubt they’d need to steer their business off its current model. May be a different story if they were struggling to make ends meet, but I guess they’re not.

The frame would be I-beam at that point, so a doddle to put up with minimal cutting etc as everything can be supplied close to the design specifications. The only undulations will be caused by the slab, affecting the soleplate, but anyone who knows this will make sure the slab perimeter is 100% bang-on. The extra time and effort spent there will pay huge dividends downstream, when erecting a near modular 'kit' eg I-beams cut to size off plan to nearest 30-50mm and simply trimmed to fit. Once at the wall plate height, and any slab level / issue has been rectified, the next uprights should all be identical. With doors and windows set outboard of the openings, I do not see the need to over-insulate here? Marmox sheets would offer up a decent thermal break if you wanted to go nuts, just bond them to the AT OSB, then bond the PB to that. Quite unnecessary tbh, (afaic), and never seen this on an MBC PH TF build. The only lamination I have provided on these builds has been to use Marmox to line the openings of the roof lights / lanterns / etc and then plaster directly to that. You cannot run insulation continuously over electrical wiring, and if you run horizontally everywhere you'll need an electrical outlet to define safe zones on every single wall. Just beef up the frame, keep the insulation where it should be, and have open service cavities. KISS? Yup. The PH certified architects have made that choice / specification on the clients behalf, so yes, it'll be an incredibly low-energy dwelling for sure! Should be a nice and quiet home too, as Warmcell is excellent at keeping external noises out. You cannot run electrical or plumbing services through the insulated web spaces, but you can run MVHR ducts as long as they are mechanically restrained and kept tight against the inside face of the internal chord. Drilling permissions for I-beams would need to be observed, but a few stray MVHR ducts should be fine.

MBC are robust afaik. Joe has a very good set of ethics.