Tadpole

@SteamyTea My only experience of heat pumps is one on a swimming pool in a Florida villa rental which burst into life loudly, early in the morning and was audible whenever it was running. Unfortunately, other considerations mean we will have the ASHP on the same side of the house as the "opened at night" windows of our bedroom. If you are inferring that a correctly designed solution will not have a noise impact then I'm ready for that. @JohnMo thanks for the feedback and the document - very interesting

Intro: We are (soon) building a Potton SIPS, 2 storey, pretty conventional house in north Wiltshire. It will have ASHP, UFH downstairs mostly tile, upstairs carpet, MVHR, 3.6kW in roof PV facing SW, HW recirculating. Data: 94 sq m ground floor @0.15, 210 sq m internal wall area @0.15, 90 sq m internal roof area @0.12, 16 sq m windows @0.94, 1.6 sq m Velux @1.00, 12 sq m bifolds facing SE @1.20, 4 sq m doors @1.00, 1.6 sq m Velux at 1.00 People: 2 active retirees, lots of guests that stay for a few days. We like to be able to hold 21-22deg in the winter, have plenty of hot water, enjoy the quiet when we sleep (ideally ASHP off between 2300-0700). Minimal, supportive automation is planned. The above data plugged into Jeremy’s excellent spreadsheet reveals: Monthly heat energy input (kWh) for minimum OAT between 1080 and 2049. Total heat loss power (W) = 3311 for delta T = 25deg (-3 to 22) Questions: 1. How to convert all of the above into a suitably sized ASHP? 2. How much to allow for DHW? 3. What size HWC? 4. Major brands seem to be favoured by those not confident with DIY – any brand / model suggestions? 5. Is it really worth having wet UFH upstairs other than just the bathrooms? 6. How best to inexpensively mitigate externally against overheating due to the bifolds? 7. I am seriously considering a modest split AC unit in the master bedroom - any brand / model suggestions? 8. A more passive solution could be an electric Velux in the east-facing vaulted ceiling of the master bedroom – currently just 2 x electric Velux in the den/family room – to encourage purge – views? If you have read this far – thank you. When we embarked on this (ad)venture I had no idea of the scope and variety of systems that are increasingly commonplace. With the help of this brilliant forum I think I now know most of the questions to ask and understand almost all of the responses. As my requirements / ambitions are pretty conservative – almost mainstream – I hope these questions and the eagerly anticipated responses will be helpful for others.

Sorry - ran out of editing time. I'll prepare offline and try again

Intro: We are (soon) building a Potton SIPS, 2 storey, pretty conventional house in north Wiltshire. It will have ASHP, MVHR, 3.6kW in roof PV. Data: 185 sq m floor @0.15, 210 sq

Thanks to all who contributed. Our (likely) plumber gave me one of -those- looks when I suggested not bothering upstairs. I've now settled on wet ufh upstairs on the basis that the incremental cost is not significant; and one day when we want to sell, we won't have to explain or justify. thanks again - now for my next topic (pending).

We are building a pretty conventional Potton SIPS house with ground floor wet UFH, heat pump, insulated raft, triple glazed, MVHR..... Most of the time there will be just two of us in a 3 bedroom, 3 bathroom house; so only one bedroom & bathroom in regular use. For the first floor our plumber and project manager both want to install wet UFH. It will be in some sort of grooved or clipped panels as it will go in after the first floor flooring is down. Here's my question. I've read quite a few times on here of people who installed it but don't ever turn it on, people who didn't install and don't regret it. I haven't seen any examples where someone chose not to install it, but wishes they had. So, are you out there? thanks in advance

thank you all for your comments. If and when I resolve this I'll update

I hope this is in the right forum - feel free to relocate. As we proceed - with help from BH - on our custom build, approaching Passiv, home, I have been asked by several friends and family what cost-effective changes they could make to their existing home to reduce its energy consumption. They typically live in houses built in the 1960's to 1990's. There's plenty of talk in the media about ASHP and grants / rebates. There's also plenty of talk on here that says that's a waste of time unless you have an insulated slab. The house we're leaving as an example was built in 1997. It had air-filled, very draughty cavities and 100mm of glass fibre in the loft. Both of those were easy to retrofix. So my $64,000 question is - based on the huge collective knowledge here - what would you do first, and second and third? thanks

The planning passport for our custom build collides with our aspirations in the "big room across the back." I'm trying to plan how we use this space, in truth trying to fit a quart into a pint pot. There's just us two active retirees with family nearby who will pop in, mother-in-law who stays for a few weeks at a time, plus visitors from afar. The overall dimensions of this space are as shown (drawn by me from our designers proper drawing). The bifolds (SWMBO decision) across the back face the back garden which faces SE. Feedback from here might help one of them to be sliding doors instead. I'm the main cook and would like a recirculating induction hob in a 'generous' island. I'm aware of the 1m recommendation for space between island and facing units and I've been used to 800mm in the past. As drawn the island seems to be rather wide to be usefully used when cooking and when eating. If we can manage our finances well enough the fridge freezer will be the Liebherr pair (ouch! but lovely). The dining table is 1830x910 and we would ideally like to keep it. The Velux are in a sloping roof. The space in the corner of the kitchen is to make space for a shower in the cloakroom. We also have a sitting room and hobby room (cum disabled bedroom if required) on the ground floor. It's our habit to watch TV together in the colder months while I cook, then after clearing up we sometimes stay in the same space and sometimes migrate to the sitting room. I think our desires are (in roughly this order): - clearly segregated sitting area - we plan wet UFH with porcelain wood plank tiles throughout this area and hall and utility - generous / statement island or L shape with seating for 3 minimum or 4 preferable; recirc induction hob plus maybe a small prep sink - don't want to waste space but do want to leave some space so it doesn't feel crowded - TV visible from sofa and from kitchen (currently 55" which I can see OK from 5m) - if possible space for a seat by one of the bifolds where I can watch the birds, read or snooze That's about it I think. All suggestions will be very welcome. thanks kitchen-dining-den v1.pdf

Thanks to all. As there's 3 upstairs bathrooms and 2 inhabitants using just one of them, I've settled on electric UFH and radiators because of the control and flexibility. After this terrific response I'll post my next quandary shortly.

Awesome, thank you both. @Russdl especially that towel tree. @Nickfromwalesyou confirmed several suspicions of mine - I strongly approve of KISS. cheers

Thanks in advance for any help and guidance. We will shortly start on a 3 bed 3 bath SIPs house with wet UFH downstairs, ASHP, MVHR, solar PV - maybe SolarWatt battery. Mostly 2 retired active adults with frequent visitors. As I work through so many decisions, I'm currently stumped with this one. It's really 2 separate questions but they are related for me. So bathroom floors will be porcelain tile. I'm torn between electric UFH or a zone on the UFH? If the latter should each bathroom be a separate zone or just put all 3 on one for simplicity. If electric - which we have currently - each bathroom would be independent. Towel rail needs to be big enough for 2 damp bath sheets, preferably side by side. I've seen examples 1000mm x 600mm. Again if wet, each on its own or one zone? I'll post some of my other dilemmas in the relevant sub forum. thanks

Thanks TBC. I had a spell training sales reps and one of our many standard "lines" was "there's no such thing as a stupid question, only stupid answers". Adrian, yep, northern edge. I've noticed others being somewhat coy about exact locations though apart from that not bothering me, there's plenty of clues in my username and Potton.

Hello. What a wonderful fount of knowledge and genuine experience this forum is. I've been stalking for a while collecting ideas and information. After many many years of wanting to build our own home, including 3 failed sealed bids on plots, we have managed to secure a plot. It comes with a custom build planning passport to design and build a Potton SIPS home. We're both retired and enjoying life so we've secured the services of an experienced project manager. We are close to a design to go to planning but still struggling with the internal layout of the kitchen - dining - sitting room across the back. I'll be back for help with that shortly. I'll try not to ask too many stupid questions and I'll do my best to return with a post describing the outcome following any help I receive. I'll also contribute where I have something useful to others. Thanks Derek