ProDave

Which house is yours? the side of the wall painted white or the side of the wall plain brick? Is is a retaining wall, i.e. different soil levels each side, first picture suggests it might be second picture not.

I am not sure that would even give enough heat transfer from the ASHP? Why not just fit a proper new heat pump cylinder and go unvented. It will be a revalation if you have always had a vented cylinder before.

The only boarding I had to hire help for. The rest of the entire house with standard 12.5mm was doable with just me, SWMBO and 2 dead men.

In the event I need a new EPC in 10 years, I would give the new assessor EVERY single page of the full SAP calculations so there is no doubt he has the full information.

Why that choice of Sunamp model? This https://midsummerwholesale.co.uk/buy/sunamp-heat-batteries/sunamp-ehw-ipv-12 says input source is grid electricity or solar panels. (solar panels will not do a lot in mid winter) So it won't heat from the ASHP. You would be fitting an ASHP just to heat the UFH? A more conventional and cheaper system would be an ASHP heating the UFH and a hot water with an unvented cylinder (heat pump model with high capacity input coil) where you have the flexibility to heat the hot water by the heat pump or surplus PV energy. Imho you want a compelling reason to choose a sun amp, such as your 2000sq ft house really does not have a suitable cupboard to house a big hot water tank?

Just to add for those that don't know, with staggered joints between the two layers of fireline.

Do you mean you have two ASHP's?

Mine is not and probably never will be on the Postcode Address File (long story) but is on every other address database you care to mention. I insured ours before it was complete, when we only had a certificate of temporary habitation and I used this company on a recommendation from this forum for being flexible. https://gsi-insurance.com/

Most built in dishwashers sit on the floor like any other so you want the flooring to continue under them.

There is a commissioning sheet supplied with the cylinder and can also be downloaded and printed. That needs to be filled in. It asks for qualifications etc of installer amongst other things. That is what BC want.

The difference between most people and a self builder. When I gave all the as built details, including the air test result to my EPC assessor (full SAP) my instructions were, if it does not achieve an EPC A, then do not register the EPC, instead discuss with me what improvements I need to make it achieve an A before the EPC is registered. Building inspector at completion remarked this is the first house he has seen with an EPC A

In a stud wall, yes. You don't say construction method. A lot harder in a block wall. There are some constraints to do with safe zones. e.g if you want to "move" a socket and the cables for that run down from above or up from the bottom, then moving it removes the accessory that creates the safe zone, so it might be easier to leave it where it is and add the required socket to one side as an addition. New socket above should be simple. Adding a new socket to the side usually involves drilling through a stud or 2 so you will likely have to partly unscrew and spring a board forward to drill through the stud(s).

Is this another "need to keep the compressor warm" type of issue? Similar to Mitsubishi where some models have a sump heater? In this case they keep the compressor warm by continuously running it at a low level? Not all compressor types need this so yet another hidden "feature" buyers need to be aware of if they want to minimise rogue energy use.

It seems manufacturers only fit them if you ask. Our Rationel doors turned up with key locks both sides but they supplied thumb turns on request and I swapped them.

Why dozens? That perhaps provokes a discussion of where in your build is the air tight layer? Warm or cold loft? I have a total of 8 cable penetrations through the air tight layer. Not understanding the bend radius issue?

Don't over think it. Drill the smallest hole that the cable will fit through, and seal around the hole and the cable with air tightness tape.

As this is a packaged consumer product, I would have assumed when they sat "100% SOC" they have already managed the battery management internally and that might only be actually 85% of true capacity but that is all they are ever going to charge it to. and the 100% they tell you means "that is as full as it gets"? some clarification would be handy.

When the ASHP "shuts down" it should give a fault code. Post here what it says, picture of the controller if possible to show what it says. High immersion heater use from new might be poor set up. Ideally you want your hot water tank set at no more than 50 degrees, that's about the limit of good performance from an ASHP. Many of them, if you set the DHW temperature higher, they default to using the ASHP up to about 50 degrees then the immerrsion heater to get it hotter. Any competent electrician or plumber or even a competent teenager could read the manual and check through the settings to see how it was set up by installer.

I have done a few now, plumbing and wiring for my own, wiring only for a few others in conjunction with a plumber. I really don't know what installers are frightened of? From a blumbers point of view it is usually just like a system boiler and HW tank. It can be a little more complicated for the electrician as every one is different, which just means you have to read the manual and do what it says. 2 days each trade should do it normally. I suspect the issue is your standard plumber and electrician won't know how to size one. Easy on a new build house where you have had a full SAP design done giving you the heating requirement. I do agree it is time the over priced MCS cartel is shown for what it is and their near monopoly broken. The worst part is the government BUS grant is not benefitting the customer, but lining the pockets of the over priced installers. If you have a plumber and electrician willing to install it then just do it.

I would be chuffed if I got that low. So I would say well done.

All you are doing is show just how lousy the detail is on MOST houses in the UK. You could spend a lifetime sealing each and every single hole and there will be as many more left that you can't see / reach. Most on here will agree it is easy building a house from scratch to get it well insulated and air tight, by correct detailing while you have access and use of membranes, tapes and sealants where appropriate. What you are showing is the outstanding problem of just how do we significantly improve the older UK housing stock (and in some cases not so old!!) that was built without such care and detail. I have a friend who has been doing that to an old stone cottage with surprisingly good results, but it has been a LOT of work. Room by room, over many years, one room at a rime he has stripped it back to a bare shell, all plasterboard off walls and ceilings and all floor boards up. Then and only then can he seal all the poor detailing, insulate it, and finish off with an air tight membrane before re boarding and re flooring. I doubt many want to go to those extremes?

Those cupboards into the eaves under the window ring alarm bells. Anything similar I have seen is poorly insulated if at all and leaks like a sieve. Get your blower door on that room and I bet you will find howling cold gales coming in there. That looks like an access trap into a crawl space to the right of the cupboards, again likely to be poorly insulated and draughty. But put your head in there with a torch and you will get a good idea of the quality or otherwise of insulation and detailing there. Take some pictures and post them. The other common detail I often come across is you take a socket or switch off the wall on a windy day and get a cold icy draught coming out of the hole, meaning detailing is poor and cold air is able to get where it should not, and I am talking about switches on internal walls here. What should be simple tings like sealing cable holes from a cold loft down into an internal stud wall.

So you have a bit of a leak through a poor window or door seal. Does that get "fixed" and the door or window now won't open?

I am not sure starting a new thread with the same question will get different answers? It is your neighbour that is taking the risks. If you are really worried alert your buildings insurer about the possible threat to your property and let them go and have a look?

For me, not until surveyors have got over their fear of it. I have just been organising the home report for our old house, and one of the very first questions the surveyor asked was "is there any spray foam insulation in the house" the implication being it would be a problem if there was.