Conor

Running costs of the IR will be about 3x more than the ASHP. And for water heating as well as without some sort of boiler/heatpump you'll be using direct immersion heating. The rate you've been given for UFH is about 4x higher than what I paid. About £4k for 270m² over three floors. (I did some of the pipe laying myself but probably only saved £400) However... If you are building to passisive standards and have minimal heatoad, then some sort of low level direct electric heating running off peak is a serious option.

@Thorfun I've no idea on either count. It was what I could find locally, and the borders installed it as they went. Best £2/m² I've ever spent.

Isover accoustic rolls. They'll fit in fine.

We used 50mm everywhere, every single wall and ceiling void, seems to have worked a treat.

ITS group, 4.5pkW. couldn't go higher due to the size of the roof and single phase connection. No batteries yet. Just gone a full year so might do the calcs on that.

Some sort of block and beam floor. Can't tell if the infill between the T beams are standard blocks, large blocks or insualtion blocks. Looking at the very bottom RHS suggests an insulated type infill, e.g. https://www.cemex.co.uk/suspended-floor-systems Further reading here https://www.bdonline.co.uk/cpd/cpd-4-2017-insulated-suspended-floor-systems/5087724.article Pretty standard stuff these days, tho not that widespread. Normally overlaid with more insualtion and then a thin screed. Inherently "bouncy" over longer spans, natural quality of reinforced concrete beams. Bugger all you can do about the bounciness if that's what is annoying you. Unless the builder has exceeded the manufacturers / engineers span tables or inadequate intermediate supports. You'd need a camera survey done via the floor void to confirm. As it's a recent build, the design drawings and calculations etc should be available via building control.

What are your overall U values and heatlosses for each room? No point thinking or planning any further until you've that work done first. As this sounds like a full on renovation and extension I'm sure you're at least at the required building control levels of insualtion? Have you upgraded the glaslzing etc? What's the proportion of old uninsulated walls to new, insualted walls? Is there a loft you can insulate? Before you plan about how you're going to put heat in to a building, you have to plan on stopping heat getting out. Plenty of topics on here about heating old buildings, have a search. You need a manifold on each floor (various reason, mostly to deal with air in pipes), each with pipes coming from the ASHP ) buffer tank. UFH might not be the best option for you, esp upstairs.

Did my PV myself with just a spark to connect up the sparky bits and test / signit off. If you're doing a new build then an in-roof system is a no brainer as you save a fortune on slates and no issues with planning compared to ground mount. You get pretty good payments in the south these days for self generation so I'd fill your roof, as much as your ESB connection will allow you to. Start the convo now with them, will take months.

Yea, the AAV needs to be on the main 110mm stack and higher than the highest trap.

More than adequate. I pulled our 1.5 story red brick bungalow down with a 1.6l VW golf and a long chain.

Your structural engineer will be able to calculate this for you. Re fire, not an issue, you'll just need to adequately protect them if they are structural parts of an escape route or protected area. I'd advise getting your drawings and structural design sorted before going to a builder, you'll need all that for building control anyway.

I had this issue with my tanked basement slab... spoke to architect and the SE that both inside that it was fine. We were moping up puddles of water the day before we put the insualtion down. A year later, no apparent side effects. In your case, I would have thought the main dpm would have gone on top of the concrete slab, not under.

I'm going for a square shower trap. It's only really for an emergency in event of a big spillage or leak. If you want to go get the floor wet regularly, then you'll have to go down the whole wetroom tanking and sealing route.

No, my solar edge Inverter has connections for two strings. Optimisers fine in the in-roof tray system.

£6k for a heatpump and tank sounds cheap. My coolenergy was £6300 (far cheaper than a big brand) ex vat excluding pipework, lagging, pumps, valves etc. Easily another thousand. But sounds like that is on top of their costs which is crazy. So all they are doing is dropping it in and connecting it up..is it a preplumbed cylinder. Is there a buffer? Our install labour worked out at about 7 working days, £1400. Excluding the UFH stuff.

Classi seal around the bath, tape up the corners and tanking paste in all splash zones. Realistically it's about £40 of material and an hour's work. I wouldn't not do it.

Only way it works out cheaper is when there is excess solar (rare) or, like us you run it on a cheap overnight tariff for a limited time. We're paying 10p per kWh, and with a SCOP of 3, means we're paying about 3.5p for every kWh output, less than half the cost of a gas boiler. But that 7 hours is only enough when it's relatively mild, 7c or higher.

Cut it back, plant a nice slow growing mixed native hedge and be done with it. You're well in to high four or even five figures for any kind of digging back and mechanical retaining wal. Looks like you've plenty of space elsewhere.

What's the existing retaining structure? I'd be wary about touching it. 1.5m is a substantial amount of earth to retain, as it's a boundary, you want to be extra careful.

You won't need reinforcing if you use 50mm cementious liquid screed. And it would be more normal to add fibres and addmix to the screed. One less job to worry about

Another Elica owner here. Fantastic piece of kit. Have it in white and looks class I've yet to figure out the temperature hold function (e.g 42c so you can souvette or 90c for slow cooking) and it's not in the manual. Other than that, 10/10.

This one with a solar panel. https://m.reolink.com/gb/product/argus-eco/ Need a WiFi network.

I've two of the WiFi models. Be very wary of the connections on the solar panel and the usb in to the camera, I destroyed one because the rubber grommet wasn't tight around the usb port and water got in and corroded the usb port and board. I also had the bracket on the solar panel snap off in a storm.

When I say balcony, it's actually a beast that's going to drain the last bit of cash we have out of us!!! I'm getting the C24 and not deviating from the drawings... after all they cost me £1500. It's all essential as we've no access to the garden from our ground floor, and I eliminated the cheaper option of an exposed timber balcony a long time ago.

Was the ceiling plastered or did they just fill over the joints and screw holes? It's not the best but I wouldn't say it needs to be redone... A good run down with a sander and another coat will work wonders. Try taking photos in daylight so we can have a better look.