JohnMo

No, the expansion is on the cold side of the system connected to the inlet group. My hot pipe goes up 50mm, horizontal for 300mm and then down. To minimise those pipe losses.

Think you may be mixing up cold water and hot water, the discussion is about vented and unvented cylinders - all hot water will go to all sinks and outlets from the cylinder on a vented or unvented systems. A vented system may have have a tight fitting lid on the loft tank, it also an open overflow. Doesn't get looked at from one year to the next, very few people will service a vented cylinder. I have fished out dead small animals - maybe not rat sized but definitely a rodent skeleton. On that occasion the lid was so distorted it would stay closed, have seen them with no lids. I wouldn't have a vented system even they gave them away.

Mine looks pretty close to this, but just used thermolite blocks, but installed a 70mm wide PIR upstand inside the blocks before the screed (in our case 100mm concrete), our doorway straddles the block and PIR, weight taken by brickwork.

I would say Raised of ground - need planning New structural design that is raised as well needs structural engineer Needs fall prevention ballastrade etc, needs a structural engineer. Nice project enjoy.

There is a whole thread on here somewhere.

That's basically what I said, unvented is hygienic water, vented may not be, is unlikely to be, you would want to drink it.

Unvented - high water flow rates equal to cold water. So you have decent showers, not long to wait for water to hit the tap, way quicker than a combi. It's also hygienic water, exact same quality as cold tap water. Way more hot water for the same cylinder size when compared to a thermal store. Vented - rats or other animals drowning in the loft tank, making unvented cylinder not fit to consume. Low quality shower experience unless you add more pumps. Bigger thermal losses as you have a vertical pipe coming out the top connected to the loft tank.

Real issue with all the auto generated stuff, it looks plausible, but the fact is you really need to fact check, everything written. Not on this forum, but another, have seen facts given, as believable by the person writing the post, but in reality were rubbish generated by an AI bot. So check and check again - as you will be seen as the author and have fix a mess up if not correct. One mistake I noticed (or the text needs tidying up) that it states justification that fire truck can turn and not reverse on to the main road, but it wasn't clear where the turning point was. It seemed to be close to the road junction, but has to at the house end, as the fire truck isn't allow to reverse. They can also add in what it sees as relevant details about similar things, which could be altogether different or fictitious or at best not helpful.

That would only have insulation as sound proofing not other reason. You may need to let us know your wall construction etc. You really need to start with some basics information and look at the benefits of what you are doing. You already insulation which is a start. One of the biggest heat losses is uncontrolled drafts, they are generate cheapest thing to fix.

And they them individually and so does Screwfix.

But what does this actually mean in reality. Assume they mean some form of warranty, but what does that cover?

I've seen it mentioned on here before that Cool Energy are MCS registered so I am not sure if they do scheme similar - may be worth a chat

That's stupid money, ASHP and the grant system is geared around fools with plenty of money. A 9kW Panasonic is only £3k + vat, cylinder £1k, a few big K3 rads £1.5k. so you quote is about £8 to9k labour! Yer right, more like a couple of k and pocket the rest as profit Apply for planning and do a DIY, shop around fir good prices - with trade assistance when needed.

That is just nonsense. Sack him or tell you want what you asked for, there is zero warranty that means anything anyway. Sounds like he will be installing a high prices coil of tube. And possibly a load of additional bits you don't need especially in a passive house or anything close to one. You just need pert-al-pert pipes on 150 to 200mm centres, no more than 110m long per loop, to a suitable manifold. No zones, so no actuators or thermostats, no mixer no pump. Run the whole lot from heat pump or boiler on a very low weather comp curve. A wireless thermostat to control heat source. You really don't need him trotting off to do a design at your cost,once you get below 20W/m2 they come back rubbish anyway, massively over engineered.

I would do neither of those, definitely not detail 1, its not structural. You must have a structural opening that is designed to take the weight and wind loads, this requires input from your structural engineer. You have no need to rebate compafoam, it needs a flat top for the flat base of the roof light to screw down on too. Your typical install details are this, which you need to modify as you are a warm roof (insulation on top) Notice how they (Roof Maker) say to use a 40 to 75mm up-stand, this is what you are replacing with compafoam, the roof maker sky light already has part of the upstand built in to the unit. So build a wooden structure first, this is the structural element of the roof and opening. As previously discussed, don't waste a small fortune on making the whole up-stand arrangement from Compafoam as it isn't cheap and doesn't add to the thermal values. You only need to start as you come out of the PIR layer. So the above gets modified to something like this

Are the skirtings painted, natural or something different? More info required

Seems a good choice for a stairs.

Dulux trade paints for me, every time. You will now get almost every alternative paint available, so good luck. Why I like Dulux trade, very high pigment content and covering power, you can get it easily (B&Q etc).

Save your time and effort, just buy this and follow the instructions. It's pretty harmless to use. https://www.fertan.co.uk/product/fertan-rust-converter/ Or as @Onoff says.

More rubbish costs for the tax payer to cough up, and pay some company to manage. More upfront costs for a heat meter and dedicated heat pump electric meter that read and record in almost real time, so CoP and SCoP make sense - all of this kit has to be paid by someone - either the tax payer or the person having the kit installed. "If your Scop was actually 3.0 you would only have paid £1,165 and you're actually "made" £235" but the metering system just cost £600 installed. The OP install and many others on here show the cost of install doesn't need to be high, or cost prohibitive. Fact is a new full price heat pump isn't much of a cost premium over a good quality system boiler. And because the installer system see a cost benefit for the consumer in the way of a subsidy for a piss poor install, the consumer will still be ripped off. Sorry don't believe any government money spent on these schemes, is money well spent. A couple of years after the grants were abandoned on PV, costs have dropped like a stone.

Why? That will just be abused by the unscrupulous. A heat meter records negative heat output when cooling, so anyone could make the system look like it's got a poor CoP, even if fantastic during winter. Just make all plumber training mandatory on low temp systems - then what issue? A simple low temp system should be getting a SCoP 3.5 min in the frozen north and 4 and above especially in the moderate temperature zone called southern England. Stop grants, they are just getting rich quick schemes, the general public carry the tax burden front end, and as a consumer with shoddy practices and poor workmanship at the end.

I just made all my changes in a pdf viewer. Had to move a boiler and a few other things. Cut, copy and paste various bits from the original drawings on to new locations.

That's what I used for the fence. With no torque adjustment, just have to be careful with the trigger finger. I used SS ring grooved nails for the cladding, several thousand.

Depends on size of screws and at what torque you are driving too. I just finished a fence all SS screws, nothing pre drilled and had not a single screw issue. I used ones with a square drive hole and corresponding drive bit. This is what I used https://www.toolstation.com/deck-tite-plus-a4-countersunk-screw/p35337

No Compafoam goes above the wooden frame would have similar dimensions to the Compafoam upstand. The opening shown on my last sketch is the aperture for your skylight. So is showing the left and right of the aperture. You would line the aperture with 25mm PIR then plasterboard or what ever you want. So nothing like your drawings.