JohnMo

Really you need to read the mounting system install instructions and know the wind zone you are. From there it will tell you clearly what is acceptable. You also need to confirm with your structural engineer the roof build up is acceptable for any additional loads imposed (uplift and downwards forces). Taking hear say from the internet is not good enough. If you are doing a MCS install the installer will have full responsibility for what is or isn't acceptable. But with all things it's worth checking yourself and questioning.

Not agreeing with much of the above. Since September I've generated close too 2,500kWh, nothing much exported. I'm in NE Scotland, so plenty more solar would be generated further south. My summer bills will consist of mostly standing changes. Electric suppliers cap what can be exported to what the local system can handle. Using the correct crimping tool to make up connections is a must, other than that is all very straightforward.

Thickness of material in metres divided k value (metric units) equals R value. Add mutiple R values together for different materials used 1 divided by R value is U value

If you are not going underground it's not a cost effective solution. I would just tell the installer you want to put 100mm of your 150mm insulation below the pipes. If you want everything flush prior to screed you may need to trim the 100mm down a little. Leave there 13mm insulation in place.

If they don't give me a discount I say an alarm isn't there. I had one case many years ago where we bought a house with a monitored alarm system already installed. The stipulation from the insurance company was to be maintained annually from an approved list of contractors, had to be set everytime we left the house and at night. My insurance came down when I said it was no longer installed. Go figure.

Winter gain and summer gains are different sides of the same coin. Winter you will take all you can get from solar gain. We have close to 4m overhang, but a wall of glass some of it due west, by 2.30pm today we had to close the blinds to keep the sun out. Currently 23 in living room and 14 outside and we had the UFH cooling on for about 6 hrs today. Don't underestimate the power of the sun when mixed with glazing. This is a photo taken just now, due west the sky you see is the path the sun takes and it drops behind the trees. You can see the glow of the sun behind the trees to right.

Still tastes rubbish and if salt based there can be issues with salt content. But you could always just use a Poly Phosphate based cartridge system like a BWT combi care. Just put it in the fed to the UVC (22mm). Change cartridge every 12 months. Not a softener as such just stops or reduces scale buildup by stopping the process. A simple explanation here https://silksoftwater.com/water-treatment/water-conditioner/polyphosphates-in-hard-water-treatment/

I would just biased the pipes to the the top of the insulation. Or even on top of it, depending on screed thickness. Certainly wouldn't be at the bottom, no matter what the contract says.

Look at the value for 150mm and 200mm the difference in the values can be added to each additional 50mm or half the value for every 25mm.

This is unlikely to help, as when the sun gets to the west the sun will be low enough to shine straight under the overhang

That was my plan with the battery and big chunk of concrete, but smart meters just don't communicate here, so limited to E7 or standard tariff.

Only thing not to like about SIP panels is they are thermally lightweight and have a very short decrement delay. The decrement delay refers to the time it takes for heat generated by the sun to transfer from the outside to the inside of the building envelope. So in this case maybe not the best choice for summer comfort

Typical U value calc for the build up proposed Wall Type 3 - 169mm SIP Value 0.17.pdf https://www.ecosipshomes.co.uk/wall-u-values Condensation calculation Wall Type 3 - 169m SIP Condensation Risk.pdf

Or just taped without the skim. Some high wind load areas (Scotland) may also require a blockwork outer skin also (plus a finish) , which seems the norm for timber frame building. So could soon get to 400mm thick and not the best U value.

Contracts are a two way street, not a one way street. If you don't like the terms, propose something different, he can take it or leave it or counter propose. The original proposal was I paid for materials weeks ahead of delivery, but negotiated to day of delivery, prior to entering site. Both parties happy.

No, not really, I paid everything in arrears except the roof rafters etc, I actually paid that the moment the lorry pulled up to our drive.

I came from a different direction RAF, so aeroplane engineering, where a loose bolt is very bad, a missing bolt could be catastrophic. So was always working with gravity to ensure things stayed where intended. Then oil and gas, where a dropped object could easily injure or worse. So again always inserted from the top, never the bottom. When I started in the oil and gas industry and we experienced multiple bolt failures on reciprocating compressors, analysis of the failure mechanism was bolts fatigue failing. What was happening the bolts were not tightened enough, (difficulty getting bolt tensioning equipment in to the tight location), so the bolt wasn't in the elastic range, where the bolt can stretch and contract indefinitely without fatigue failure.

I was in the same position and never got a warranty. Really couldn't see the point of paying out a couple of grand, to line someone's pockets for not added benefit for me.

Passivhaus standards can be met with any build method. So you achieve whatever you want.

There are zero mechanical advantage to the threads beyond the 2nd thread overhanging the nut. In fact aeronautical engineering would only have 1.5 threads out of the nut. The strength from bolted assemblies come from the bolt/stud being approx midway in the elastic range. This is why it's important to torque assemble. Bolted assemblies fail more from being under torqued rather than over torqued.

Our living room gets to those temps! That isn't even that hot

That's not good engineering practice, the thinking is if the nut came off the bolt falls out, bolt from top, nut falls off bolt stays in place. In this case would it matter?

So the buffer is really serving no purpose, or is it. Notice you have 8m and 6.5m head pump, it could be that one pump on its own cannot do the correct circulation rates. So you need to do the pressure drop calcs, you may end up with a monster single pump to keep the heat pump happy with the small bore piping. As said apart from the second pump the 3 port configuration is pretty good as you get very little, or no mixing of the flow and return, but it allows hydraulic separation to have multiple pumps. And provides a good ventilation point.

You need to leave about two threads out the end of the nut, other than that fill your boots.

I would convert to 22mm at the stop cock. Place hot water manifold close to cylinder and then run from there in 15mm Hep2O or similar to the wet rooms. If you are not using the balanced cold water flow from the unvented cylinder inlet group, put a prv after the outside tap (if you have one or after the stop tap if you don't) that will ensure everything downstream is pretty much the same pressure for mixers etc. You will also need a check valve at the unvented cylinder hot water outlet to prevent any chances of reversing flow.