PeterW

Just use dry sharp sand before the DPM and then lay the insulation. It won’t move after that.

That sounds about right - 1.225kw was what I calculated it to. Telford will lose about 7.2c in the same 24 hour period. An additional 1.2kwh of heat per day at CoP 2.5 is about £15 a year in additional electricity or £350 over the 25 year life of the cylinder.

Yep they do straight through pipes for Geberit frames.

Polar Energi don’t make heat pumps - they make cylinders. They use Panasonic ASHP external units. Both Mitsubishi and Panasonic are decent brands so either is fine.

Yep I know one ..! Newark Copper Cylinder will make whatever you want with whatever thickness insulation you ask for. Only reason I didn’t use them was because we got such a good deal via Cylinders2Go

No the calculation is for all perimeter walls for the void so you 12 vents overall.

60 minute fire protection assuming its two layers .? If not then it is 30 minute with a single layer.

Going for 60 min then in there - I would for the additional cost and also it’s good for noise.

Oil boiler in the utility ..?

Timber frame and gas boiler in there ..??

Welcome. £60 would get you access to the Timber Beam calculator for a month Here Conversely I would suggest the quickest and simplest method would be to use steels and make a goalpost arrangement at the front. A 7m steel with a UC upright at both ends, and then one between the doors would work. Your issue is not the beam above the doors here btw it will be the compressive load on the timber frame. Also, who has calculated your roof loading ..? I make it 128kg/sqm which for that build up seems light. You’ll also need to use 72x220 joists at 400 centres to get your spans.

That is tiny - in the Telford HP UVC Range it is 3.3sqm as standard.

do you mean WBP Ply or Marine ply ..?? There is no benefit in using marine ply as the only guarantee is the voids within the plies and there is zero stress on a flat roof unlike a boat hull.

Seriously stop worrying about it, foam the back of the boards and get them fitted. If any of it feels hollow or flexes when it’s dried, drill a 10mm hole in the board, shove the nozzle through the hole and squeaker some more foam in.

You have photos to find the timber if you needed to and to be honest you just drill and plug it and be done with it. The foam is very good - easier if you lay the board flat or sloping and just put beads of it down the boards. Wait 5 mins and lift into place, press against the blockwork and brace for 10 mins and that’s it.

There is no gap It basically squashes to about 1mm if you push hard, or stays at 5-10mm if you don’t. Just use the foam ... have you got a squirty bottle as it will foam better if the wall is damp. Just use clean water.

Which adhesive ..??!! The spray foam stuff you put on in 1” beads and then leave it for 5 mins to go off and then squash flat and it sticks.

@zoothorn just cut a piece of PB to fit the wall - use the foam to bond it to brick/block and then use screws on the timber frame. Just poke a hole where the switch needs to go.

and if it’s under the stairs then it’s inside ... ?

Are you looking for a turnkey solution then ..? If so, get the contractor to quote for the lot including the drawings - many will have a preferred SE or AT they use, and will happily work off basic plans to start with. If it’s PD I’m assuming you’re using the neighbour approval system ..?

Definitely a cable. You may find the door is just being pushed open by the seals - a decent tight fitting door compresses the seals and will push open when the handle is released. And why do you want this “feature” anyway..? Do you let random strangers into your house from 50 miles away ..? Are you expecting the Tesco delivery driver to put the shopping away for you too ..? Or is it for when you’ve forgotten your keys and you can get back in ..? Out of interest - how does it behave in a power cut ..? Does it fail safe and open ..??

OK - assuming this is a rectangular box going on the back of an ordinary detached house, and there is a single knock through (??) and it is of standard construction with no unusual quirks such as corner glazing or full width bifolds.? If so, why the drawings..?? If you are going with a main contractor then tbh a standard plan and elevation annotated with the standard details would be fine, and I would even go with a building notice instead of plans and let the contractor crack on with it. Standard Details

Any steelwork or Structural engineering required..? Does the application include the BRegs fees ..?

So go with a thermal store instead ..??

That’s just crap design ... and no fail safe..? I’m assuming this stuff is all insurance approved..??