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If your architect is telling you it now complies, what makes you concerned that it doesn't? Your instructions to the architect should be to produce a compliant design so whether it complies or not shouldn't be a question. I certainly don't know enough to tell you it complies and even those here with more knowledge likely wouldn't want to confirm it now meets regs (none of us know enough about your situation). People will happily highlight flaws if they see them. From my limited knowledge of the regs I don't see anything obvious (but I'm no expert on the regs and last read them well over a year ago). If you have a specific concern maybe highlight it so people can give their thoughts. As far as improvements go, it's very difficult to say without knowing and awful lot more about what you want out the space and the restrictions you are dealing with. It does seem like a compromise design but everything in building is a compromise and maybe that's the best given the constraints you are under.

Won't this cover manufacturers who provide calculations? (assuming they follow the mentioned guidance) If you SAP accessor is willing to accept self signed (from someone with no expertise or insurance) but are not willing to accept the calculations done by manufacturers engineers (with expertise and insurance) then we live in a strange strange world.

That is where you should ask others. I've done a lot of research on heatpumps (both in the past for my current place* and as a prospective self-builder) but have not actually had one installed myself. *Ended up being too complicated (I thought) to do in my flat given the need for freeholder approval and roof access. Something I regret now as I had more money at the time and if I'd pushed through that I could have the ability to cool my flat and would have avoided a huge amount of hassle and cost with gas boilers.

Doesn't you architect understand the rules? That's a big red flag, you are paying them for a compliant design. Even if you came up with your own design and then went to an architectural technician they should still be fully aware of the rules and be able to advise you of any issues/propose fixes.

Expanding on my thoughts. If you have ground that suitable for this solution and are happy with the performance then it's a valid option if it is cheaper/quicker/easier to install. But I suspect you can get the same performance from a traditional foundation with somewhat lower cost (can get any groundworker to do it vs a specialist) and the industry is just much more comfortable with the engineering of traditional slabs which may make other things (insurance, future sale, warranty, etc) easier.

I missed that before, sorry. Still not sure it really changes my view. Marmox blocks are good but they are still much lossier than the other mentioned solutions. There is also nothing stopping using marmox blocks with a traditional foundation and save all the custom eps/engineering costs (use it on the inner leaf and ensure the non-load bearing floor slab is thermally broken from the foundation).

That looks cool. Just need to find a suitable competent person willing to use it and sign which might be a problem. Having said that, in time this looks like a solution that will work once the competent people get familiar with it.

That's a pretty stonking great thermal bridge there. Not keen. Both AFT + Kore systems have thermally breaks between the inner and outer leaves. With that thermal bridge I'm not sure why you would bother with the extra cost of an insulated raft vs traditional foundations. What U value are they claiming?

I really think you should call a few installers and see what info you get from a first chat. I don't know the amount of back and forth you've had with Gemini but I suspect it's only giving you a partial (at best) picture. There are planning permission issues with multiple heatpumps, 2 is the limit now I think so you might be ok but would need checking. Also worth checking that AC style units comply with the MCS noise limits. The water based monoblocs are generally all MCS compliant but AC units might not be as they are more often used commercially and if you want to use them for heat you need to make sure they are sized correctly for UK winters (some aren't). I suspect an AC installer would be able to install an overall AC system for a bit less than Gemini guesses. There is also a £2500 grant available for AC units similar to the Boiler Upgrade Scheme though I think less complicated (not sure how it's claimed). Still given you are planning to replace pretty much everything going to a water based system with fancoils is likely possible for a similar net price quoted above once the BUS grant is taken into account.

The EU are doing fine. They have been putting record fines on the tech companies for non-compliance with various rules. Not sure about advertising. But most of those rules we have too as they predate Brexit. The amount you can bring in in fines should easily pay for enforcement. The pre-existing EU derived rules have plenty of fines based on % of revenue/turnover (depending) and so does the Online Safety Act. EU court has just ruled that under existing rules the tech companies are liable for content on their platform so they can be sued if they host defamation, take part in fraud (false advertising), etc. Again those same rules should apply here. Basically this country should stop making excuses. The government has already shown it can force the tech companies to implement ID/age verification all over the place that in my view is a huge detriment to the open internet ('want to access this reddit post that might contain the answer to your tech issue, we need to create an account and verify your identity first'*). If they had put the same energy into forcing the companies to take responsibility for what's on their platforms the platforms would likely have got much more kid friendly, fraud would be down, etc. * We aren't quite there yet. AFAIK you need to verify ID to post but not to read, but with the under 16 ban I can't see how they implement that without every website like reddit being completely blocked until you create an account and verify ID. Even if you are ok with doing it for one site, if you are doing a search and you get 10 results and every webpage on the list requires an account and verification to proceed it becomes completely unusable. People will just ask AI instead (which creates a whole host of other problems).

Did they include calls from the ASA to extend regulation to online platforms? Or talk about how Trading Standards/Ofcom does likely have the power? Or call for the platforms to be held liable for false advertising? I've got a bit of a bee in my bonnet over this stuff. We have too many people saying 'we can't do anything'. Yes, yes you can. You just need to get parliament to act (and likely not a major action as most of the rules are in place already), maybe you can't right penalise the companies but you should be putting equal effort in to obtaining that power. Put enough pressure on the tech companies and they will comply but if you are weedy and defeatist about it they will work around you.

Sure and I'd guess even most DIYers aren't going to be capable of doing anything other than the most basic system, unlike that proposed. A middle ground is the umbrella scheme, where the scheme provider does the design work and you take care of the install with the provider coming in to do commissioning and sign off. Likely costs are possibly cheaper than pure DIY as you do get access to the grant, though it will take more time and co-ordination and options are limited. For a complex install as we are discussing it'll be extremely difficult to find a viable scheme.

Based on reading peoples experiences on here if you are a competent DIYer and you can get easy/low cost access to an electrician and plumber to do the regulated bits then you can self install for a similar price than you will end up paying an MCS installer. (The MCS installer will take the grant and charge you much more on top partly to cover MCS, etc, overheads but also to make a tidy profit). Having said that if you are not confident in your ability to do this stuff then getting an installer in is really the way to go. The effort should be spent on finding a good one.

Tend to agree, especially if you are installing for the express purpose of using 'smart' features that most companies seem to support for about 5 years and then end-of-life leaving you stuck. Or a heatpump UVC if you want. Yep. If you want one heatpump to rule them all then stick to an air2water monobloc and run everything off the water loop including fancoils. I think that's what the Samsung system is doing but the Daikin system is not. I wouldn't want refrigerant lines running all over the place in my house. R290 is not an option for that (very strict limits on its use due to flammability) so you end up with R32 which requires an F-gas certified person to do anything related to the pipework. DIY not an option.

No comment if you plan to use something native to SmartThings, but if you were thinking about integrating into Home Assistant I've just seen that Samsung have announced they will charge a per month subscription if you want to use Home Assistant.