Nickfromwales

£2k to effectively kill cold bridging for a 6 figure project is negligible, aka ‘cheap’ in the grand scheme. Compacfoam / other would need pricing to get an effective comparison here tbh, so it’ll be down to your own diligence to surmise what is best / perceived ‘cheap’ etc. Yup, agreed. Sectional drawings would help, as we’re currently drawing conclusions from what info is available here.

Happy days. Just read it back and it’ll take 22mm pipework. Thank me with beer. 👍

For a drain point you can accept a compromise here. 21.5mm o/f pipe will actually seat quite nicely into a 22mm push fit connector. So 22mm pipe into one side, and 21.5mm into the other will work. Tbh, you could even use a 22mm compression coupler, with a 3/4” olive in the 21.5mm side. None of this would be anywhere near the chat if this was either a potable or a heating circuit, but it’s to save you using a hosepipe so we can allow a pinch of “it’ll be fine”. Go with a push fit coupler is my advice, but when draining just go easy vs tap wide open at max wallop. For belt and braces you should go into a 22mm x 22mm tundish, and then into a suitable waterless trap (eg so you can see when it’s finished draining off).

Yup, by commissioning a gas boiler (gas burning appliance) you are bringing to life a lethal device. If it is less than a 100% complete and compliant installation then it’s very simple, you do NOT supply it with gas and you make it “safe”. That is done by either cap-ending the cut gas supply immediately prior to the boiler, or by installing a disc in the supply from the gas meter so gas cannot be let into the system by turning the supply EGC on. This is simply stuff you do not play devils advocate with. It is either a) fit for use or b) left disconnected from the gas supply. You can fill it with water, power it up, check it functions to the point where it locks out on flame failure, but you CANNOT set it to work with a live gas connection, thus allowing it to then create carbon monoxide. The laziness of this guy is apparent in every single, solitary, aspect of this job. Left unchallenged this is how he will do the next job. A bag of ready mix mortar is £10. 15 mins to knock a mix up and trowel it in. No excuses. Seriously? His builder will be shitting air-bricks, and will instantly revert to a state of self-preservation. He will not be a wise choice for an ambassador for this?!?

I think a couple of pics would help.

Yup. Pretty much what is on site at this project. 30mm PIR upstands against kicker blocks, and Marmox on top / immediately under TF sole plate. AT tape starts at 1st 100mm layer of PIR and then top layer and joints taped / foamed again for belt and braces. Internal AT membrane then comes down and gets taped to the tape already on / across the Marmox blocks. PIR updstands hidden by internal service battens + PB + skim.

I’m currently on a SIP’s type build (TF with 140mm PIR infill) and Marmox was the obvious choice there, plus under the large sliders. Also for the rising intermediate internal walls. All of these are significant cold bridges. IMO you should 100% go with this detail, with the top of the Marmox finishing above ToC, but I am assuming this is not on a raft foundation?

Ok so that is for a hot return arrangement. This is where a pump circulates the hot water from your cylinder, past all the hot outlets, and back again thus leaving you with near zero delay getting premium temp hot water out of any outlet. Most cylinders come with a tapping for the HRC (hot return circuit) to connect to, but not all homes are plumbed with a secondary return. If your ASHP guys are raising this, then they should have been more useful eg at least attempt to give you a comprehensive explanation! You may not have any plumbing for an HRC, so there may not be an issue. If they can see a pipe marked HRC which is capped off and needing connecting and a pump adding then this is half a days work to complete. We need a lot more info to be able to help you.

This is one of the laziest examples of a boiler and cylinder install that I’ve seen for a very very long while. Looks like a (poor) 1st year apprentice did it! Not a clip in sight, and for that amount of pipe work I would have wanted (expected) to see everything in copper as it’s in such close proximity to the boiler. If this is the finished article and he’s signed it off, then WTF? The condensate and D2 pump(s) should have been segregated afaic, regardless of regs it’s just a sensible standard. The 2x PRV’s should have combined and been dumped into a pump that has attenuation, like this LINK and what you have there is defo no good. If you like, go down there and open the 5bar PRV on the control group and see what happens. The flue install is a) unsafe (the appliance should NOT be on atm! And b) embarrassingly shoddy with, as said above, insufficient mechanical fixings. He has tek screwed the joints, but on a windy day the products of combustion will be entering that building (unless he’s installed a snorkel outside? Pics?). Not even any clips on the gas, and that’s in pressfit ffs so needs all the help it can get! This isn’t even a 3 out of 10 tbh.

How many stories is the house?

Just do a basic heat loss calc to get a ballpark number for kWh requirements per room. Rad sizing per room is free on a lot of supplier websites which will give you and idea of heat required, but obvs a bit hit-and-miss in terms of absolute accuracy. "It is what it is", but if the natural rates of infiltration are above the trickle rate of MVHR then you're just pumping in cold air 24/7/365.

That'll be A-OK

Hi, and welcome aboard! What foundation system have you gone for? Twin-wall TF or SIP's / other?

Only effective if the property is "airtight" to a min of 1.0 ACH (or under).

If someone posted pics of a ‘messy’ cavity, you’d see that this guy is actually working to keep the cavity clean. Architect will just repeat what is written in the guidelines, but most architects can’t build a house. Each to their own. You’ve nothing to worry about here, and I’d go tell the builder what you’ve been told about his work. There will be a cloud hanging over him otherwise. Nothing worse than that.

Option 2 lol. That’s referred to as a “22-15-15” tee, or “end and centre’ reducing. The spur of the tee is called the centre, so a 22mm centre tee (so you can branch off a straight 22mm pipe run with 15mm pipe) is referred to a 22x22x15 tee, as you call the centre (spur) as the last ‘dimension’. If the run to the combi is long, I’d run 22mm pipe most of the way tbh.

Stick them low level next to a hidden double socket. At least they blend in / are out of eyesight then

Don’t get me wrong, the majority still ask about a battery as a cash-generator, so those ones get dissuaded unless we can see a minimum 30% RoI, as anything under would equal shitty advice tbh.

It’s welsh for “here you go”. Works just fine in England too. Yet to try it in Scotland, and I was too pissed to remember what happened in Dublin. I do remember how bloody expensive it was out there though, so doubt I heard it from any barmaids as they never gave change, regardless of how many notes you handed them.

Yup. Don’t put the switches / spurs at the bathrooms, they look ugly! Hide them in an adjacent room or cupboard / closet etc.

What outputs can the Loxone give? Zero volt switching or 230v out? How many amps per 'channel' etc? The UFH mats will be using very little power tbh, so just treat it as a lighting circuit and run from the 3a switched fused spur (you'll need to retain a means of local isolation) back to the HA cabinet? Saves a relay, but the relay may be the cheaper option. Just remember to go solid state, or you'll have clicking noises coming from the relay which may have been better left at the HA cabinet

Beer and bacon. Roll on the hotel bar this evening, and breakfast at 07:00. 😋

The same one that's bent us over for the last x number of decades, yes, that one. We will graciously accept any injection of funds to the local infrastructure. But please don't be any more of a prick. What, like a magician does when the rabbit disappears?

I am on borrowed time with my boys free-standing, vented thru-wall unit, so am thinking 2 outdoor units and 6 internal. When (bloody ever) I get to put my now dusty solar panels on, the gas bill can be offset by microgeneration. Summer cooling will be blissful. I am jealous btw.

Bingo Bango Don't be tempted to buy cheap, you need reliability and longevity !!!