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I wouldn’t bother trying a core drill. For that width you really need someone who has all the right kit to do it. much easier to dig out.

Same question? Off top of my head. - higher temperatures needed reducing efficiency - if replacing radiators for oversized to reduce temp needed then a significant cost and possibly unpopular if it means losing more usable space - Ufh costs a lot to retrofit and needs insulation to be effective so larger cost - issues with electrical supply on larger properties, possibly smaller ones too (to be fair I don’t know how easy to overcome this is) - capital costs of replacing boiler for ashp - waste of embedded energy of gas boiler if replaced before its’ usable life span - finding space to fit new hot water tank if replacing combi boiler

Accepting the danger of appearing like a Dave apologist I feel like some responses to his original post are attacking the messenger rather than dealing with some of the issues. the idea that we can just switch over from gas boilers to ASHPs en masse is deeply problematic. It is the sort of idea that could become government policy without really dealing with some of the issues. Draughty and poorly insulated old housing stock is not an ideal fit for heat pumps. Nor are new builds that scrape through building regs at best and at worst wouldn’t pass if we had a building regulation system fit for purpose. Solutions to these problems are not straightforward but surely they have to include better building standards/regulation and decent incentives for upgrading housing fabric. Clearly we need to make the switch to heat pumps and reduce reliance on fossil fuels but this can only happen if government can think longer term and actually grapple with the issues. The message of reducing energy use rather than just switching to a ‘clean’ energy source needs to be hammered home and built into standards/incentives. Fabric first.

Just a general point when asking for buildhubbers’ experiences of ASHPs - I think it would be fair to say that those who are part of this forum will by and large be building homes much more suitable to heat pumps as they are much more concerned about build quality/insulation/air tightness. The real problem is new builds by big developers that install heat pumps without the build quality as heat pump performance will suffer. So be sure to try and get real world experiences from those with substandard new builds as well as here.

Can't you use a wide enough bucket so that you get a straight pipe down each side of the trench?

probably easiest to post a diagram with a scale to make it easier to see what is going on. Presumably the length of the proposed extension is 7.4m which exceeds the 6m max length for PD for a terraced house. (detached is 8m limit I believe). So you could build to the same length of the existing 6m long room under PD but to go further you need to apply for planning.

I ended up replacing the whole pipe that goes from tank to this chamber. Probably for the best as it wasn’t in the best state! Thanks for all the advice

It is an overflow chamber for the septic tank. I’ve replaced a failed pipe with the plastic. Previous pipe came out from the very bottom of the chamber and my new one comes in just above it. the whole chamber has been buried under a fair bit of earth so would require a fair bit of landscaping or raising if it was to become an inspection chamber.

Just shingle and perforated pipe

I believe that for a clay soil a geotextile membrane won’t help much since the membrane itself is prone to clogging up. Sandy soil is much more suited to a membrane.

I'm trying to join these two pipes together. The 110mm plastic pipe is about 200mm below the original clay pipe. Any ideas on the best way to join the two? I could chip away round the clay pipe enough to get a rubber collar around it i guess. And what about once I can get around the clay pipe - is it just a question of a couple of angled 110mm joints or is there some flexible rubber option that might do the job easier?

I wouldn't have thought they need anything. Once it is established as a dwelling it is unlikely to go mouldy like it has. See what you can do to brush the mould off now and then see how it behaves once in use.

You can get tape that sticks to the timber and then you render over the bit of tape on the wall for airtightness. Why not use glassfibre or rockwool? Much easier to fit than rigid baords.

I have done a couple of my own roof structures myself. Used a normal sprayer and permethrin. More ventilation the better, make sure the timber is dry so it soaks up as much as it can. Did about 3 or 4 sprays. Proper mask with filters, gloves, goggles and painters disposable overalls. I never looked into getting quotes so can’t help on that.

Get the landlord to sort it out?

I might be wrong but I think minimum U-value for domestic is 0.16. For non domestic it is 0.22. These figures are for new build, not renovation but I believe a barn conversion is effectively a new build - but I could be wrong. can you not just go for 100mm external insulation? No need for internal insulation then. Then either render straight onto the wall or vcl/ battens for service void / plasterboard.

What are you planning on constructing the dormer sides out of? for PD I believe that it should match the existing roof (so if clay tiles then vertically hung clay tiles).

Parge coat. Are you internally insulating or externally?

What is the coil in the MVHR? Does that do both cooling and heating via the MVHR? And presumably require extra pipework to the MVHR?

I haven't looked at prices recently but i remember when I bought some last that Steicotherm boards (for plastic fixing to walls) were considerably cheaper than other options. But I don't know off hand how they compare to Pavatex Isolair. And you can still chase cables into the boards, put some capping over and then render.

Do their heat pumps work in reverse for cooling?

a. yes : better to use lime but for a small area probably won't matter using gypsum b. no c. definitely no d. no original lime render is performing a role as an airtight layer so bet to leave it in place. The other overall option if the existing render is reasonably flat is to use woodfibre boards that are fixed directly to the walls without any need for studs with a lime render on top. But I am guessing it might be a bit late to consider that.

Very Nice

Put a tilt fillet under the last bit of membrane so that it can’t droop and allow water to pool there.

Is there an electric shower?