ProDave

Our cat flap enters into the sun room, which is an unheated room outside of the sealed envelope of the house. It lets the cat in to a relatively warm and dry place and we let her into the house through what is a good pair of external well sealed Rationel doors. One feature of an air tight house, is you can open one window or door without getting much if any through draught. So in practice but a sealing strip around the door from your utility room to the rest of the house, and you might find the fat flap does not swing wildly in the wind.

You need a new electrician. Shame you did not question this here before you gave him the job. He s only responsible for making the new, or altered circuits compliant with current regulations. The simplest way would have been to fit rcbo's in the existing board if they can still be sourced (i.e not an obsolete make) So what has he done? Post a picture of the CU as it is now. I am guessing a split load board with 2 rcd's? What exactly is tripping? One or both of the rcd's or one of the mcb's? Once I know what you have I can advise more. As for £90 to fault find his own work, the second word in my reply to that would be "off" To test for earth leakage faults you need an insulation resistance tester. As you are not doing this professionally so are not interested in a calibration certificate you can usually find one for not much money on ebay. But it is also very likely your fault is not earth leakage but a borrowed neutral, very common on old lighting circuits.

T&e is fine if not exposed, i.e straight through the wall into the isolator. Flexible conduit is often a better option from the isolator to the ASHP rather than SWA.

Check with your local regs and BCO. Up here it is a minimum of 1200mm by 1200mm flat in front of the door. One (presumably) 900mm slab would not be enough,

From the link to the smart thermostat: Safety Independent mechanical safety mechanism So I expect the thermostat housing contains a relay and the normal mechanical over heat cut out, so it would still comply with G3. But not if you start butchering it to give it a separate supply source.

Yes that is what is required, but I have a feeling the Tesla switch in the OP is not configured like that and would require a certain amount of alteration if it were even possible.

I expect with that limited space by the time you have got the flat area in front of the door, there won't be room to get the ramp straight out. So more likely you will then have to have the ramp sideways, i.e. parallel to the front wall of the house. That would allow you to just have steps from the front of the flat area down to the drive as well, so convenient for everyone.

Keep us posted. It is sometimes difficulty to keep a clear head and diagnose exactly what is wrong.

You need to be clear in what way does the pump not work? Does it just not pump, with power applied? OR does it keep on tripping the RCD so power does not stay on long enough to see if it works or not? Quite likely insulation breakdown on the cable causing earth leakage and tripping the RCD. You need an insulation resistance tester to check that.

You are tackling this the wrong way. If it is excess solar that you are mainly using, then set the immersion thermostat as high as it will go. If you set it lower, then when your tank reaches say 45 it will turn off and your surplus PV will be wasted. So let it just heat as much as it can while the sun is out, and if tomorrow is cloudy and not much sun, you will have plenty in the tank for another day. I would also question if this will actually work for you? Most solar PV diverters supply a pulsed or power limited feed to the immersion heater to match the amount of surplus solar PV. I would expect this smart thermostat will be expecting a continuous power feed to it in order to operate, so I would not guarantee it will work when connected to the output of a solar PV diverter.

It can be very variable. My building warrant was delayed several weeks while we tried to find an acceptable drainage solution, only solved when SEPA finally said why not discharge to the burn. But then when we installed the treatment plant, BC were notified and did not want to inspect any part of that. All they were interested in was inspecting and pressure testing the drain pipe leading from the house to the TP.

You WILL need to check building regs before you go ahead. And sorry I am not up to speed with English regs, but in Scotland, a treatment plant must be 5 metres from a building, 5 metres from a boundary and 10 metres from a watercourse and you WILL need a building warrant to fit one. If your front garden is only 5 metres wide I don't see it being allowed there even if it would physically fit. but you talk about your field, so why not run the foul waste pipe under your garden, under your drive and into your field where you should have plenty of room to fit the treatment plant there? A sketch of your site layout would help. If the company is suggesting something that may not meet building regs then choose a different company.

You need to be sure it will fit in the front garden allowing for all legal distances to buildings, boundaries etc, and you have permission from the EA to discharge to the ditch.

That is the very last one I would want. You don't want to be the person replacing a jammed gearbox in that, and neither does anybody else. So I guess it's go it alone, BUT that relies on you having enough of your own land to do that, access to that land to get a digger in, and access to somewhere to discharge it to. If you need consent from your neighbours for any of that, then it is going to get difficult.

I would go for a new shared system but make sure it is a treatment plant, NOT a septic tank, and choose one that works with an air blower to agitate the contents, not the sort with rotating mechanical parts.

I read that as 7336 total maximum heat loss, which seems high to me but is in line with what the MCS estimate says. I found similar calculations in my SAP were 2 to 3 times over the actual real world heat loss.

At 400mm centres you frame around the opening probably needing doubles on at least one side of the opening. Regarding C16 vs C24, I was building my decking frame recently and accidentally found if I ordered 6 metre lengths they were all C24

There is unlikely to be any damp proof membrane under the concrete of that sub floor, so it is probably just ground water. That is why under floor ventilation of that type of floor is so important, so check carefully all the air bricks are free, not blocked, and most importantly, not covered by external ground level that has been raised too high and is blocking them.

We have a frght mixture of upstairs ceiling heights. The whole roof structure is hung from ridge beams so all rooms could be vaulted right to the ridge if wanted. But we only did that with one room, which has a mezanine above the adjoining small bedroom. Landing and bathroom we did a normal 2.4 metre ceiling to give us a just about standing headroom bit of loft space. And the master bedroom we did with a 3M ceiling height still giving us a feeling of most of the available height, while giving a further bit of crawling height loft space access via a step up from the main loft. If you want smaller joists to preserve headroom why not fit more of them at 400mm centres or even closer? At 400mm centres I used just 12mm OSB as the loft flooring to preserve headroom.

What I learned in my first self build (ordinary insulation levels no mvhr) is heating in the hall, and definitely on the landing was not needed. As stated up the thread they are "rooms" with little external wall and borrowed heat from other rooms, and in short the UFH never came on in either the hall or landing. Second self build I did not waste the time and effort laying UFH pipe in either the hall or the landing.

Good news. Just be aware the cupboard it is in may well be lined with Asbestos cement board, so get that checked if you plan to modify the cupboard when it has gone.

Sounds a positive step, but the devil is in the detail and as we don't know that it's impossible to say if it will be any better. Lets hope so.

Welcome back. We obviously don't know the details of why you stopped. That is personal that you may or may not want to share. All I can say is be positive and flexible with your plans. It would be a huge wrench for me not to complete. In our case it was unforeseen financial circumstances that forced a re think, and our revised plan was a very much slower "build as you earn" build with us doing far more of the work that we expected to at the start, but we completed and are now comfortable in our new house, and the eventual sale of the old house that caused all our problems actually left us better off in the end than we ever expected. So chin up, formulate a plan B and move forward.

If you do a proper heat loss calculation, e.g use Jeremy's spreadsheet available on this forum, it calculates the ventilation heat loss properly. If the MCS calculation does not do that, then it is flawed. Why do we tolerate a system that specifies a heat pump size without calculating it properly?

I have a contrary view on plant rooms. There is a trend to put everything together in one plant room. But is that the best thing? Not always. It was brought home to me when I wired a friends house, a plumber, and his plant room contained all the usual things, the mvhr unit, the manifolds for the UFH. the consumer unit and the hot water tank. Shame was, this put the hot water tank at the diametric opposite corner of the house to the kitchen and main bathroom. I similarly had a "plant room" designated in the room above the adjoined garage. But as it evolved, the only thing in there is the mvhr unit, and a few of the heating controls and a pump. The rest of that room is now my workshop / office. The HW tank is in an airing cupboard in the corner of the spare bedroom, giving it the shortest hot water route to all the taps. The UFH manifold is in the utility room putting it central to all the UFH loops. The plumbing manifolds are under the floor under the bathroom with access through a ceiling hatch in the utility room below, optimised for shortest hot water pipe routes. Consumer unit is on the wall in the utility room for convenience. All network and AV gear is in the cupboard under the stairs optimum position for short AV cable runs to the 2 main televisions. It just made no sense whatsoever to try and put all this in one place.