ProDave

As above, 25mm batten and 12.5mm plasterboard is perfect for a 35mm back box.

Taking down a lath and plaster ceiling is a miserable job. But the best way to start from a clean slate with a fresh clean ceiling. Re the walls, I would batten and plasterboard leaving the old stuff there. The main reason being I never ever want to rewire a "plastered on the hard" house again. I left that miserable task behind when I moved to Scotland where most houses are timber frame or battens and plasterboard on the walls.

+1 for Frametherm 32 But what else are you using? 140mm insulation in a timber frame is not enough on it's own. So what else, external wall insulation, something over the inside of the frame? It needs to be designed as a whole package.

Thanks for the clarification. Frankly I would just move it back a touch so the front edge of the unit is in line with the front of the house. So the back edge will be less than 1 metre from the back door. What practical problem is that going to create? Who is going to notice let alone measure it?

Can you explain the drawing? There is a rectangle box and an L shaped box, joined together by a red dotted rectangle. If one is the original and the other the modified position why the different shapes? If there are two outside boxes what are they? In any event I seen no harm in moving it / they back to the L shaped one is in line with the front of the building.

They must all stay together. The easiest way is a fly lead from the earth terminal in the back box to the earth terminal on the switch. Strip a bit of 3 core flex to get a short length of green and yellow for the fly lead.

This is more likely going to be a planning issue if it is in front of the house. Care to post a plan showing old and new location?

Cooling can easily be powered in summer by solar PV, which will be in abundance when cooling is needed. Just about everything else can be adjusted for. I look forward to winters when we don't get a week or more of -10. The one I never hear discussion of how we are going to solve, or deal with, is rising sea level. This has been talked about for a very long time. I don't see any evidence yet that it is happening (being a boater I watch tides etc) But if the predictions of a large rise in sea level do come true, how are we going to deal with the many coastal cities and towns that will find themselves below sea level? Massive defences? Abandon them and relocate?

The frame is easy. What about the actual heat exchanger, how are you making that?

For the as built SAP my assesor required confirmation that wall floor and roof build up was as proposed, in my case roof insulation was more than originally proposed. They required Uw values for all windows, design SAP would have been assumed. Air test results, design SAP assumed 3. Actual model of ASHP fitted and stove fitted, design will have been assumptions. And amount of solar PV fitted. As built SAP came back better than design SAP as expected.

The ones in the metal frame are especially strong to support a wall hung pan. Totally pointless if you have a floor standing pan.

At least this is painted. Wood filler is your saviour. You wait until you try Oak architraves.

Well I failed to find any suitable pipe to go in it or outside it, so I set about trying to connect the detached bit, as it was now holding up my rebuilding of the bank. So first I set an ordinary concrete block in, in front of the piece of pipe still embedded in the bank. I offered the detached piece up to it and it seemed to sit okay and stable. So I "fixed" it in place with stixall,. which is one of the many glue / sealants that claims to work when wet. A Very generous bead all around the end of the detached piece and then push them together quickly. It seemed to seal okay with no water leaking from the joint. That's okay, but it would soon get knocked out of place when rebuilding the remainder of the bank. So I mixed a barrow load of muck and encased the whole lot. Once that has had a chance to set and harden I can continue rebuilding the bank.

CLS stands for Canadian Lumber Standard. It is usually nice stuff to work with, with slightly rounded corners. Perfectly fine for a non load bearing stud wall, if I use that I normally build at 400mm centres. Simple enough to box in a concealed cistern, it needs a lot more thought if you are going to mount a wall hung WC pan on it.

+1 to the above. It sounds like you want to use ICF because you believe ICF is good and timber frame is rubbish. Your existing timber frame is probably rubbish, because it was built years ago, probably with a thin lightweight frame and little or no insulation. A modern well built well insulated timber frame house is as good as any other modern well built house. You can build to passive house standards with almost any build method if you want to. I would as suggested above build the extension in timber frame and strip back, repair, strengthen and properly insulate the existing structure. How much work it is renovating the existing structure depends what you find when you strip it back. IF you find the existing frame is rotten, you might be better doing a full rebuild with the advantage of 0% VAT.

A well set up ASHP heating system, will deliver a COP of about 3, which means for every 1kW of electricity consumed, you get 3kW oh heat. With electricity being about 3 times the cost of gas, that roughly means an ASHP will cost about the same as a gas system. Your problem is a poorly insulated house, with two 30kW boilers that struggle to heat it and cost a fortune. To replicate that amount of power with an ASHP is impossible, and even if you could, the best you could hope for is similar running costs. Anyone who says it will be cheaper is an eternal optimist.

No,I just know it is common knowledge the big house builders are only sample inspected. There are no end of complaints and newspaper articles about defects, missing insulation being a common one. As I say, they have proved themselves untrustworthy and whoever allows this sample inspecting should disallow it and make sure every single house is inspected.

I would advise you to edit your post and remove your email address. If you want a particular member to know it, send them a PM

Yes this is a big issue, big housing developments only a sample are inspected by building control. That needs fixing imho they have proved they cannot be trusted so every single house needs inspecting and defects corrected before sign off.

Yes, first dose (daily for a week until it started to turn brown) appeared to work. Then a month later a few shoots appeared again, only in 1 of the three places, so daily does of Gallup XL for another week until they turned brown. Finally 1 month later just 2 shoots which got the daily treatment for a week again. I expect that is the last I will see of it this year as it's turned cold but fully expect to have the sprayer on standby ready to pounce in the spring and just keep at it.

YES. They would get it right next time. When I last had a proper job, the industrial unit I worked at was having an extension. A big gable end of the building had been built of brick and block cavity wall. A few days later they were taking the outer brick wall down and then re built it. Building control had failed it for the wrong cavity width or some other detail. If they are made to put incorrect work right, it will focus their mind to get it right first time.

But until BC inspectors have the balls to go up into a loft like this one and say "Sorry chaps, that insulation is not installed to an acceptable standard, it has to be re done properly before I will issue a completion" then mass market builders will continue turning out sub standard rubbish. Most self builders will do it properly because we are mostly self building to get a good house at the end of it. Mass market builders need to be forced to do the job properly.

If you have fallen out with your original installer, probably the best thing you can do is seek out a local to you heating engineer, or dare I say an electrian that understands heating system would be the best person. It is a question of first understanding how the system is plumbed and wired and then methodically going through everything to make sure the right demands are in place and the correct motorised valves actually open and pumps pump when they should. Remote diagnostics on a forum I fear are not going to resolve much. And someone that knows the Ecodan heat pumps care to enlighten us what an L9 fault means please. P.S I don't rate your original installer very highly. He has never heard of pipe insulation up in a cold loft.

So you could do that under permitted development, 3 metres at the front reducing to 2.5 metres at the back. OR make it slope sideways and level front to back, so 3M at the party wall side sloping down to 2.5M at the right as viewed from the front. It would give you the high ceiling one side and should still be high enough to stand up at the other. But that is just your fall back position of what you could do without PP should your appeal fail.

Perhaps a picture of your existing garage? It it attached or detached? You could do it under PD as above with a pitched roof limited to 2.5 metres at the eaves, which would not give the headroom you wanted at the eaves but would in the middle. But at least you should be able to stand up at the eaves. I read it as being a flat roofed garage at the moment and raising that to an internal height of 2.7M would make it more like 3M outside which would be above the PD rules.