ProDave

So it's right by a door. You need to look at the detail of that door threshold, I bet water is getting in under that somehow.

Mine sits on a timber batten (TF house) that is not as wide as the aluminium cill, so outside the decking boards slide under, inside the floor tiles slide under.

What I am failing to understand is the height of the EV can be lower just by teeing off the pipe between the control group and the cylinder water inlet boss a bit lower down. That does NOT affect the positioning of the control group or the tundish or any other pipeowrk. So I ask again from any of the professional plumbers on here, what harm does it do if you tee off the cold pipe lower down and mount the EV alongside the tank? Everything else being equal, EV mounted upright with connection at bottom etc.

So it's a variation on an exhaust air heat pump? I would avoid personally, because I don't like an "all eggs in one basket" solution. If it breaks down, you have to fix it or replace the lot. What guarantees of future serviceability are there? I have heard storied on EAHP's not being repairable. With a separate ASHP, hot water cylinder, UFH and MVHR there is less to replace if one major part fails and cannot be repaired.

Do you have a link to the system you are thinking of? It sounds like some form of combined mvhr / warm air heating system?

Sorry you mentioned "patio" and my brain read patio door aka sliding door. Yes their French doors should be level access. On the outside leave a recess under the door opening so the slabs can slide snugly under the aluminium threshold, (in our case decking boards)

Do Rationel do level entry sliders? They didn't when we bought ours, and we have a normal slight "step"

The expansion vessel tees off between the outlet of the control group and the cold inlet to the cylinder which is at the bottom. I can see no operational reason why it would not function correctly lower down, BUT it would mean you would have to partly drain the cylinder if the expansion vessel ever needs replacing. Is there a legislative reason it cannot be mounted low down?

They will move the supply and their fuse in the morning, the meter man will connect the meter in the afternoon and then YOUR electrician will be expected to connect the meter to your consumer unit. They may or may not provide an isolator switch but your electrician should know how to deal with it whatever they do. Have him on standby for late that afternoon as I doubt you will be given a time for the meter man.

Both times I built, we had the plot long before selling the old house, so had plenty of time to get the static caravan on site and services connected. A rural plot you might well have to install a sewage treatment plant as well. And not all plots are even suitable to live on. One plot we looked at was on a very steep hill. Not only would the foundations potentially cost a lot, but we were not even sure we could create enough flat enough land for a caravan. Regards what to do in the short term, when I was visiting the site organising services etc I stayed in my touring caravan having to fetch drinking water and dispose of chemical toilet waste as you do on a caravan site. I would not want to be doing that for long.

You say that is your "front" garden. The context is not clear in particular where are the neighbouring houses, where do they front to? Normally the elevation facing the road is the principle elevation, so that to me is a side garden. Where the building line lies depends to some extent on what neighbours there are. but if you move your garage just a little to the right so it is inline with the house wall that faces the road I would say it is okay. Won't that make it a tight turn into the garage or will a car never go in there?

What you really need it a thermal camera, assuming you can't stretch to one of those, an IR thermometer would tell you if it's the ceiling or walls that are coldest hence losing the most heat. Probably no floor insulation either.

Yes basically the linesman cocked up and instead of burying a pigtail of copper wire connected to the earth, he had connected the pigtail to one of the Live conductors. There would have been a continual current passing through that limited only by how wet the ground was and therefore what the earth impedance was. And that current would have been warming up the ground hence causing the steam. I hope someone got a good talking to,.

Can we assume that this room under the garage is also a semi basement? At least the front bit of the room (front in terms of where the garage door is) must be underground. So presumably everything about the room is cold? not just the ceiling. So you are probably looking at insulating the walls as well. Assuming there really is no insulation (age of building?) then anything will be a vast improvement, even 50mm pf PIR. How much can you afford to lower the ceiling height by or reduce the room size by with wall insulation?

Have you got the building plot yet? It can take a long time to get services connected before the site is ready to move onto.

Check the socket that is is plugged into. PAT test will only confirm continuity from earth pin of the WM plug to the WM case. If the earth is missing from the socket you could get the effect you describe. Volt sticks have their uses but this is not one of them.

I think they originally said £700K was all they had and it ended up almost £1.4m

I would love to see the planning history. IMHO a far better use of the site, would be to keep the original cottage separate and 2 new builds, one being where the "car barn" is and one being the other side of the cottage. But let me guess, it's green belt and planning would not allow an additional dwelling or 2, so this abomination was the "solution" to extracting as much from the site as planning would allow. IF that is the case then I despair of the planning system. At least in Scotland, it is highly likely a new build would be allowed in the garden of an existing dwelling.

But a COP of 2 is better than effectively a COP of 1 if a heat battery and a resistance heating element is the alternative being considered in this thread.

I got most of those. Ne mention of Eco Friendly, and I didn't see two coats at once.

I am not seeing a "chimney" there (do I need to look harder?) I see the chimney breast formed but I don't see a masonry chimney coming out of the top and up through the roof structure?

That turned out to be one expensive house, that was nearly double their "all we can afford" estimate at the start. They had no concept of how to save money, e,g I would have made a habitable home in the existing building and saved building the new wing until you could have afforded it. I think they said they could have bought 3 houses for the cost of building this one.

Your problem is going to be the fact the UFH will take a LOT longer to heat up than the radiators. So if you just connect it and treat it as another radiator, don't expect the extension to be warm until some time later than the rest of the rooms, and then probably stay warm after the other rooms have cooled down. I would have a 2 port valve feeding the radiators and another 2 port valve feeding the UFH and then a time clock so the UFH could come on earlier. But you can't really do that just with the ASHP's controller. That is why I don't bother with using the ASHP's controller as a timer and just treat it as somewhere to set and look at parameters, and my timing is done with a 3 channel central heating time clock. Two heating zones with separate times and DHW on the third.

Stove pipes go female up, so any condensation running down the inside stays inside. Male up as your picture shows, and condensation could run out at a joint.

There is a little confusion here. It's not ASHP's that take an age, but under floor heating. Even heated by a gas or oil boiler, UFH takes a long tome to warm up. I think you are talking about an electric heating element for the towel rail? Not a "300 or 400W TRV"? They work well, but be aware if you do turn the upstairs radiator circuit on, all the heat in the towel rail from the electric heater will be distributed to all the radiators.