-rick-

The different warranty providers do sometimes have additional requirements that go beyond pure building regs. NHBC definitely does (but doesn't really deal with self-builders). LABC have a large guidance doc that should be consulted before using them for warranty. Don't know about others. They don't want you doing things that have a high history of claims, even if it is building regs compliant.

It's probably more complex than this but I thought it was mainly: 1. Solar Gain 2. The temp difference between outside and inside (same calculation as with heating) 3. The amount of air infiltration/exchange (same as with heating though might be additional focus on humidity) The solar gain is the difficult one which is why if you are mainly north facing with some east facing windows (that already have shading) you might not need to worry too much about this. If you are south facing with no shading its a huge deal.

Interesting point. I assume banking on the 30 min billing windows as a benefit to single phase (because if you aren't generating enough solar you are using grid energy anyway?).

I thought that was sorted now. Roll out started about when you were getting one and is now in full swing?

This isn't exactly correct. The grid acts as a buffer and your electricity meter counts net generation. So you can generate on 1 phase and consume on another without being charged. Assuming you have a modern smart meter. Obviously you aren't strictly directly using the energy that you generated but I doubt that matters to anyone unless you aim to be off-grid, or expect long grid outages. A reason for three phase is that it's easier to export from larger arrays as you get 3x16A automatic export allowance, and it will generally be easier to get permission to go bigger if equally split among the phases. Agree that inside a house the need for 3 phase is minimal. There are some uses (big cooking appliances) but other than that and it's not much needed. Having the flexibility to install EV chargers or power a workshop are nice though.

Modern heat pumps are inverter driven. This doesn't present an inductive load (or at least nothing like a traditional motor). They will soft start,

Ok. that should help a fair bit. Also, I noticed your main room is on a north-east alignment. Assuming thats where the windows are you should be limited in solar gain coming from the east (morning) so peak solar gain will be much more limited in time than a south facing direction. Shading will make a big difference and limiting the duration of max gain also makes a big difference. Look at the average over the worst 4-5 hours, not the peak. The floor slab should provide some buffer for peak load also.

Well since no-one else has replied. Any luck with this? I can't see it working too well as shown. BTW: that cable looks like it needs attention.

So what did the dynamic modelling show? I know that Part O isn't enough if you want to keep the place at a steady 21 but your numbers are suggesting >6kW gain into one room. Did it specify shading strategies to limit the gain? Have you accounted for that in your calcs above? 6.5kw is a lot of heat to put into one room (even if it is a big one).

Part O requires buildings to be designed to avoid overheating, so you need to take account of solar gain/shading. Have you got those calcs from your architect/others?

What temps would that pipe be adequate for? What would be required for for 10/11oC? Anything pre-insulated on the market?

A few thoughts: 1. As a clean sheet design try and design out the need for this sort of complexity as much as possible. If that means oversizing the fancoils to produce the needed output at higher flow temps so be it. You'll have a more efficient system running with a single temp WC with no mixing. Having said that, having a design that could support dual flow temps if there is an error of design is a nice insurance policy. 2. Right sizing the overall system is important. Too big and it will perform poorly. Equally, putting effort into making sure the insulation and shading are done right can avoid the need for a big, complex and expensive system. 3. If you run the fancoils with low flow temps you are more likely to notice the cold air draft effect of A/C so it's another reason to avoid if possible. 4. As @JohnMo said the input temp to the floor can be a little below dew point without much concern as the concrete will average out the temperature (especially if you make sure a flow pipe is always next to a return pipe throughout the loop). So you can probaby run a little lower than dew point without 2 zones as long as you insulate the pipes. 5. @joth wanted the ability to cool the fancoil zone while heating the ufh. This is not what we are talking about here. If you want that it's more involved. Though I would try to design out the need for that situation as much as possible. It would be too easy to fall into a situation where two zones are fighting each other and burning money.

@Pocster seems to be starting topics on new problems faster than fixing the existing ones. If this carries on in a few years this forum will be a all @Pocster

It would (that's a new option to me). Certainly cheap and easy. Would still have to get extra equipment if you wanted to have Terrestrial TV + Radio down the same cables. Need the hybrid option for Sky Q.

I'm a long way away from doing it but I've pencilled in using pre-insulated MLCP pipe (and therefore MLCP fittings). Looks like it includes a vapour barrier around the insulation though that's something I haven't looked into. Not much insulation but I don't think you need that much so long as the pipe runs are inside the building fabric and you aren't running crazy temps. Pre-insulated looks a lot less faff than other options and the price of this stuff seems reasonable, not like the ecoflex stuff which is designed for outdoor use. Another potential benefit of the insulated stuff is it isolates the pipe from the pipe clips (use ones that go around the insulation) so should avoid any noises from thermal expansion etc. Tons of examples out there this is only one: https://cosy-floor.co.uk/product/pre-insulated-mlcp-pipe-6-5mm/ I've seen companies selling other colours than red + blue too.

It absolutely is and is how satellite is done in flats. It does require extra equipment though. Whatever you are doing make sure you use good cable. Cheap TV ariel cable won't do for satellite. Having said that, why do you want this? Sky is on it's way to moving it's subscribers to internet streaming and I'd expect many foreign providers are doing the same. Even the now old Sky Q system doesn't require satellite cables to each room. Only the main room, that box streams the channels to the rest of the house over wifi. If you are focused on free tv and want to avoid streaming services you can get satellite to IP boxes that convert the satellite signal to work over your home network with apps available to run on smart TVs to get the signal (I've not really looked into this for years and I don't know the state of this and it might be a bit too niche to give a good experience now that streamers are taking over).

If someone doesn't recognise them can you identify them from the planning permission? If they are still building more can you pop over to site and ask?

Look what you've done now!

Checked all these? https://www.fhbrundle.co.uk/gate-hardware/gate-closers This one looks like it replaces your hinges https://www.fhbrundle.co.uk/products/05GC40__Locinox_Closer_40_-_Includes_Top_and_Bottom_Brackets

Thats a different take on it but I can see that working, though how long that one lasts IDK, seems a little light weight.

The spring might need to be constrained to stop it flopping around and the product I linked doesn't do that. But I'm sure I've seen a spring hinge installed like this before so I'd bet there is a product for this.

Have to say the way they are showing these springs installed isn't the way I was imagining it. Was thinking you'd install the hinge directly inline with the pivot point so the closing force comes from the rotation of the spring. Crudely: Not sure if thats the right product to do this but it does look like you have space for something that does the above.

How about? https://www.amazon.co.uk/IRONZONE®-Spring-Closer-Adjustable-Tension/dp/B08Z89YK93?sr=8-6 Looks like it will fit in the gap for the hinges? Not recommending the product - was just the first google hit for what I was thinking of.

Putting this a different way. Manufacturers who produce a range of heatpumps will likely only produce a small number of sizes and artificially down rate the others. Avoid any that are down rated even if it means buying bigger than you need. So get the smallest size heatpump for your needs that also is not limited by software. Given whatever you get will probably be oversized, look for ones with the highest range of modulation.

Answering your actual question: That is approximately what it would be quite often. Assume a less optimal case and it working harder than planned and you should still be below 1KW, basically inconsequential in terms of large appliances. Your heat gain/cooling load will be different so worth working that out too.