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We moved from Manchester to Cornwall 6 years ago and we are very happy with the overall location. Our existing converted barn, was converted by the previous owner and is very nice but is built on three levels and has 4 double beds, kitchen, dinner, lounge and snug and 3 baths so it is far too big for us when we retire. When we bought the house I always say we chose it for the working barn apx 300m2, not the barn we live in. We are building for our future in the hope that we can continue to live her a long time, if it takes us 10 years to build we will be 65 when we move in. My husband has a history of bad backs a bungalow with no steps and easy access is high up on our want list. More recently our Greyhound is refusing to go down to the snug in the lower ground floor at night preferring to stay upstairs in the kitchen. He is incidentally another reason we bought the property, two fields he can run off lead. We don’t want anything too large, a well insulated bungalow that will be cheap to run and maintain. We have a small cow shed on our land and although our property is listed the cow shed is outside the curtilage of the property and built in the 70’s so does not require any listed building planning consultations. When we purchased the property a new build was never on the agenda, but it is now. In September 2021 we engaged the services of a planning consultant with a view to demolish the small barn and replace it with a new build, his view was favourable. In January we then approached an architect who suggested full plans would be best since what we were asking for was in keeping with the surroundings, not that much larger than the existing barn and since it was visible from the listed property more detail such as windows and cladding would be required. Two months of absolutely nothing happened then in March we met up to discuss our requirements and finally in May we submitted our plans. In June we had our necessary bat and bird nesting survey, the gentleman who conducted the survey nearly started looking at another old stone barn until we corrected him and he then told us that bats wouldn’t like the old cow shed as it would be too hot in summer (tin roof) and too cold in winter due to the holes, drafts, and thin wood walls. Then in August we had the Phase 1 preliminary risk assessment, required because we were previously farm land. From the survey I learned that in 1884 there were two wells 165m W of the site another 580m SW of the site and two quarries quite a distance away and in 1906 a smithy in the village, no surprise there as there is a house called ‘The Old Smithy” . The geological map indicates that the site is underlain by the Bude Formation - Sandstone. Sedimentary Bedrock formed approximately 310 to 319 million years ago in the Carboniferous Period. The report was very detailed but returned very little about the land the barn is occupying, that a visit to site wouldn’t tell you. Nothing bad was reported so we were happy and we continued pushing more paper around. Eventually its our turn for the case officer to look at us in detail and we get conditional approval in mid October 2022. Mid March 2023 and we have submitted our building regs drawings and my Part O Spreadsheet, window amendments to the planning department and the SE has quoted and is starting on his work. We are over 150m from the fresh water main so will need chlorinating. I found a great guy who has dug the first trench for the Water, Electric and Openreach, he will return when the new build is ready for the second trench to install the services into the house and will then chlorinate the pipework. Site electric is in from the pole in our neighbours yard towards the Old Cow Shed. We were offered a good price by National Grid for 3 phase, they would have struggled giving us single phase due to lack of supply network and another new build close to us in the village has gone off grid because there connection fee was too expensive. We wanted 3 phase any way as we hope to fill the roof with 30 solar panels facing SSW with no shading. As soon as it warms up and the field is firmer we plan to start clearing the site and moving the spoil down the field into our larger field. Doing it now would be like making a mud bath. Sometime between October and February we will demolish the barn and this time next year the new ICF build will go up. In the meantime lots of planning continues and I’m going on a short plumbing course. The husband is an Electrician by trade and can do some plumbing but hates getting down on his hands and knees now. Last year I tanked and tiled our existing en-suite and have learned all about wet wipes and silicone so another job moved from the husband to me. 😀 The main photo shows the site electric and the drive leading up to the cowshed to the left at the end and just on the edge of the photo are the old stables used as workshop storage each stable bay has a different items stored. A new entrance to our field will be made diagonally from the site electric to the left of the old cow shed which will make our farmer happy as he currently has a very tight turn left just in front of the cowshed. He comes twice a year to cut the grass and in return he usually takes at least 15 round bales away. The other images are from the architect but are already out of date. To pass Part O we are submitting an amendment for the removal of 4 windows on the North elevation and replacement with 6 roof windows that offer more ventilation. Costs to date Planning Consultant £600 Council planning application fee £500 Bat and Bird nesting survey £370 Phase 1 preliminary risk assessment £740 Architectural Design and planning £3000 Building regs Drawings £1250 SE £900 Trench and ducting etc for Water, Electric and Openreach £2830 Site Electric £2470 Openreach cable and ducting £0 Total £12660

I stumbled upon this on another forum. It looks like giant polystyrene bricks, a sort of ICF, but without the hollow core and concrete.

No timeline unfortunately but at least it’s a step in the right direction. Whether it eventually improves the customer experience in terms of time from submission to payment remains to be seen. “4.81 VAT: DIY Housebuilders Scheme Digitisation Project – The government will legislate to digitise the DIY housebuilders’ scheme and will also extend the time limit for making claims from 3 to 6 months. These measures should improve the overall customer experience and reduce the administrative burden for claimants and HMRC.” See link to full document Budget Spring Briefing 2023

It was for my son and his life quality has definitely improved, as long as he stays inside 😟. But you need to get a system that will take M5 filters as a minimum. I have the Brink Flair with F7. In the autumn/winter I go to 2x G4 and once the Hay fever seasons starts (in about a months time for my son; grass and silver birch), move to F7+G4.

As @IanR suggests, being an engineer also involves wanting to have system designs that combine known technolgies in novel ways, are elegant, and do not waste resources. Which is why I am slowly working out how to optimise a heat pump installation for a sprawling barn conversion. So I would rather have to fire up the woodburning stove and the 3kW fan heater on 2 days a year than over-engineer it for an OAT of -15C.

Evening all - thanks for having me. After looking on the market and finding nothing in our budget that is exactly what we want, me and my wife have made the decision to design and build our own house. We aren't in any particular rush - happy to figure out the basics of design first, but I've signed up to my local authority self build scheme so am "sort of" actively pursuing it. I'm completely new to all of this process, so expected this forum will be an amazing source of information for me as I go through - and I'll apologise now for asking so many questions, the first of which will be as soon as I figure out where to post it (and check it hasn't already been answered!). Thanks again for your help - and hope to see you around the forums.

I've coated the fins on my A2A units with ACF-50.

All those years of self abuse catching up with you?

Sounds like you have it. Plastic skin inside the insulation, so that humid air does not get from a room into the insulation. Breathable outside it, to let any humidity escape.

I have noticed that some brands of ASHP require special coatings/treatment of the heat exchanger fins in coastal areas but equally other brands say their HXs do not need it, sorry can't remember the specifics. As well as Blygold there is a blue coating IIRC. Have by co-incidence asked CoolEnergy about this today and will post their reply.

I think aircon units have been installed in less than favourable conditions for donkeys years. You can buy ASHP's with special coatings applied, I think I saw a daikin one last week - ebay i think coated in something that had some resistance to airborne nasties...

I don’t know but I do know there’s a specific coastal Ecodan model which suggests there is a problem.

What changed? You put filters in it What changed ? It stopped working Take the filters out completely and see if it spins up. Come back when you have done this test

If you're going through the wall and want to retain airtightness you want a https://www.schiedel.com/uk/products/additional-ranges/ignis-protect/

No problem. Buildhub is an invaluable resource for the self-builder and indeed anyone doing anything to their house. It is pretty likely most questions you have will already have been asked and answered so use the search function. A top tip is to use google to search the forum as it can return better results. There are a few books that are useful and worth getting: Self-Build Simplified by Barry Sutcliffe - walks you through all main things to think about The House Builders Bible by Mark Brinkley - This is a more general book covering a wide array of items including renovations and extensions.

So today got our box of 4 lever arch files back from HRMC, with a letter saying they agreed with everything except one invoice, which was ironically receipt number 1, for tree removal, that shouldn't had been charged VAT on. We did have a conversation at the time, Back in the summer of 2019!. But we did not have the conditions fully discharged at the time, so he didn't want to upset the VAT man, and before I discovered here. So 500 odd receipts:- There were lots of Shop type receipts [Wickes / Screwfix even 1 B&M] Which I stapled to A4 paper. I used my own numbering system, which I printed sequential numbers on small labels, and stuck them on each invoice. I used my own Excel Sheet instead of theirs. I had material invoices in the names of my tradesmen, which I had paid via credit card, due to them having accounts at suppliers and the not supplying direct to me. This I explained in the covering letter, with the numbers of invoices, and explained that Credit card statements could be provided to verify if necessary. I had invoices with the old home address on as they were delivered there, and again explained this in the covering letter. I had lots of invoices that were printed off PDF's. I had invoices with the word's copy water marked across them. They accepted the internal blinds. The invoice for the venting hob got through ! The bit I was most worried about was the bulk buildings materials that had to come through my ground worker due to not having access to builders merchant. I crossed things out of receipts that were not claimable. I crossed delivery out if not applicable, and I remembered. So all in all happy, they say it will paid by BACS in 10 days [watch this space].

House build started before new BRegs

When I was doing my metal shed at the last place I found a website that showed all that sort of detail. Says it should be vertical. https://www.mepits.com/tutorial/497/electrical/electrical-earthing-grounding

Despite watching lots of Grand Designs, building a house wasn’t something I’d ever considered until about 18 months ago. Fast forward to today and we’ve bought a plot, instructed an architect, and I’ve traded my evening telly time for browsing the Buildhub forum. So how did we get here? My partner and I want to start a family but agreed that we wanted to move into something larger first. We drew up a list of what we wanted and started our search. After months of searching / viewing we began to realise that we were going to be spending a huge amount of money just to buy something that was ‘kind of’ what we wanted. Still, what else could we do? Then I stumbled across Danwood – the polish prefab house firm – and had my eyes opened to the world of self-building. I paused the depressing Rightmove search and started reading in earnest. We went to some self-build shows, read huge amounts online, and eventually decided to swap Rightmove for Plotfinder. Our hope was to build near where we live currently (to be near family / friends and have easy access to London for work) but had no luck finding anything suitable or affordable. Funnily enough, it was Rightmove that came to the rescue. One night my partner sent me a link to a bungalow. It was small, in a sorry state, and well over our plot budget… But it sat on a good-sized plot and was in a great location for us. We called the estate agent to arrange a viewing and were politely told to eff-off as they’d accepted an offer from a developer. Back to square one. 2 weeks later I got a phone call from the estate agent asking if we were still interested in a viewing. The developer’s financing fell through in the wake of the Kamikwasi ‘mini’ budget and the bungalow was back on the market. We went for a viewing that evening, put in an offer, and a few months later the bungalow was ours! We completed at the end of 2022 and have since appointed an architect but I’ll cover that, and other bits, in a separate post. Thanks for reading - I look forward to sharing our inevitable ups and downs as we move along.

We had an issue with our Quooker Tap The lever had become disconnected Not hot or cold just boiling Quooker service came out today and said the tap was beyond repair and the boiling tank was getting to hot also He said whilst we are four years out of warranty It could be considered as a manufacture issue and replace the whole lot within the £150 call out Definitely be buying another for our current build

To give you some idea. My approach so far has been: Engage timber kit company. They’ll supply and erect the kit to weather tight so that includes windows and doors, external membrane, steel work and insulation. Engage various consultants for the technical design such as foundation, drainage (treatment plant and soakaway), private water supply etc Install electricity supply. Engage groundswork company on a fixed price. He supplied all materials and brickies except the insulated blockwork I sourced them I’ve then got quotes/tendered for every other element of the build from the roofing down. Kitchens, bathrooms, MVHR, ASHP, HA, electrical, plumbing, tiles, screed, joinery, plastering, garage, scaffolding, welfare etc, some on supply and fit and some just fit. It’s about 13 different companies/trades so far averaging 3 quotes per element and 5 contacts per element (not everyone you contact will quote) It’s a fair degree of effort tracking it all and it’s taken me 12 months to get to this point from when we signed the kit contract and 20 months from when we first viewed the plot. It was 11 months from signing the contract to breaking ground which is almost complete. The kit arrives on the 17 April and will be up by the 27th. Two week buffer in case delays and first trades on-site mid May. We’re aiming for an October finish. I’m effectively retired so have the time. Other half still works so effectively my client 😂 Hats off to the folk that do all this plus actually build it and hold down full time jobs.

Condensate is clean water and small volume, should be able to go anywhere. I have a small soakaway under the concrete pad.

Use Sikaflex EBT+ for the seal between the ultraflex on the upstand and the frame. Clean the ultraflex with IPA or Multisolve to make sure it’s squeaky clean first.

They may only put the electrical side right to make it safe. Then walk away. MCS are probably using this as an excuse to not put the real problems right, well at least for the time being.

Been making these for a mate who has Parkside tools and batteries but wants to power the odd Fakita tool. A couple of types off of Thingiverse. One that allows swapping between Makita or Parkside batteries, then a second quite clever one that replaces the Makita battery connection plate in the tool so you can only ever use Parkside batteries: The "permanent" one. A real easy print. Pre removing the supports: It's designed to go into a real Makita. In effect it's the top of a Makita battery with Parkside battery fitment. No need either for complicated battery tabs, it just uses ordinary 1/4" male spade crimps. Here fitted to a Fakita 4" chainsaw, you can see it's a tad too wide to close the two halves of the case up: On my mate's 10/12" Fakita chainsaw, a different make to mine), it's even worse: Fixed it now, just reduced the width in CAD.

I don't know if this has been mentioned on this thread or elsewhere but I read on another forum that an ASHP will now boost your EPC rating, rather than downgrade it as hitherto. This had been flagged as a change that was coming but it seems it has happened now.

Designing for a absolute worst case once in a 10 year event like -15C (where I live, anyway) is no way to design a heating system. My understanding is that most machinery works best at about half to 3/4 speed. So designing for an extreme is sensible as it will cope for that short time, albeit less efficiently. But most of the time it will be running optimally. I think many people, esp non numerate journalists, don't understand that plentiful heat is still present in the air at -15° as we all understand ice, but not absolute zero (-273°).

I like it. We've got to lose our obsession with houses being beautiful in the UK. And by that I mean lots of brick, quaint-cottagey modern builds, that planning committees love judging by the fights people on this forum have to get designs passed. The continent survives fine with rendered everything (pretty on some but the new estates in Normandy aren't) and heading for the same look would make EWI retrofit - done this way or other ways - cheaper. I am amused when I meet people who are vocal about "buccaneering Britain" but also "preserving our built heritage". If we really wanted to be that country we'd stop holding progress back and get on with knocking stuff down and rebuilding without a second thought, as they did in previous, more "bucaneering" times. Rant over

That looks just like the one I wired about this time last year and posted the picture of some of the plumbing above.

That depends on whether it's an airtight dwelling or not. AT detailing is done on the interior, and weatherproofing on the outside. Illbruck 330 foam is your friend for AT work, plus whichever brand of AT tape you prefer. Drilling through AT houses is unavoidable, unless you're a micro-managing super-human, so panic yea not I drill through each clients dwellings probably between 5 and 20 times, sometimes more, but AT test results always come in ( on MBC's stuff anyways ) at sub 0.4 ACH, because I make VERY good, each hole I make.

Yep

If the company was NICEIC registered then if NICEIC find it at fault and particularly dangerous they can ask another company to put right it it’s part of the guarantee covering NICEIC registered installers. If particularly bad the original installer will then lose their NICEIC registration.

Probably just kicking the can down the road. Only for half the year, when it is daylight. They should be reasonably safe if the ends have the standard connectors on them.

Have you considered doing it yourself / individual trades? E.g. the roof trays are easy to install (you, roofer or joiner), the panels then drop in to place, optimisers are plug in. Then you just need a competent spark to connect it all together. I did it this way and my 5.2pkW system came in at under £5k installed. (No batteries).

My manual silicone gun broke on site, and gave me the opportunity to try my hand at a DIY silicone gun. Some threaded M8 bar, some M8 nuts and some araildite metal, all hanging around the site. An hour messing about and I think that I have a passable, if rough version. Hopefully it will help with all the caulking and silicone of skirting boards / architraves coming up!!!

Yep

Wrap the whole building in plastic in situ. Guttering, slates, birds nests the lot . Nothing too technical, maybe like that black stuff they put on pallets, or bales of grass silage. It should be reasonably durable once out of the sunlight. Erect a 4 post portal frame outside it with a metal pitched roof. Then wrap the frame in some of that cement impregnated fabric they use for military huts and canal reinforcement. Wait for a rainshower to allow it to set .Then pump the void in between with EPS beads. Exhaust source heat pump for DHW and ventilation and A2A for heating. Windows and doors optional.

Hi, and welcome! I would seriously consider having the "builder" do the building, and then have kitchen and bathroom fitters / installers do the 'nice stuff'. If all has gone well with the TF, then you should have enough marbles left in the bag to choose, and direct, your own downstream trades ( for these individual spaces ). Depends on your nerves / balls / confidence, but with support here you should be able to add your own input / signature to the rooms which need this type of personal input.

Complete and utter horse manure. The internal fit is typically much longer with a masonry build. With a TF build you can be weathertight much, much sooner, and with staggeringly good results from insulation and airtightness, which are inherent from that type of build system. Masonry is a real pita to achieve the same with. MBC leave you with all walls and ceilings battened out and ready to accept plasterboard, with all woodwork ( within sensible reason ) installed at 300, 400, or 600mm centres, meaning the internal fit is DIY'able with ease. Ask someone to dry-line their own build and you'll see less people able to DIY that volume of work / have the necessary skill-set. MBC PH TF or Nudura XR35 ICF for me.

It is if the person making the statement considers it to be so

Not at all. My timber frame was stick built by a local building firm, so not quite a "kit house". After their initial quick assembly of the frame, it then took me 5 years to complete it myself. For me the main advantage of timber frame is almost the entire thickness of the walls can be insulation of some form or other. Vs Masonry where the actual bricks or blocks add little insulation. So you can get a very good indeed passive house level build with masonry, the overall walls thickness will be more than it could be with timber frame. A lot depends on what is normal where you are, in in this part of Scotland, Timber frame is normal so no problem finding a competent builder to do it right.

You can check the power consumption on the little white grant control unit. Hold the cog symbol to a 0000 comes up and using the up & down keys put in 0103 press the tick button. This is the power consumption at the time, it’s read only so you can’t change anything. 3200w was hot water cycle, heating cycle around 2700w then will drop down to depending how cold it is outside.

It has been 2 years since I installed a Brink 300/325. My main reason was 1- Hay Fever, 2- cleaner air and finally try and reduce the gas bills to help saving the environment and reducing the cost to achieve the first two. I have checked the gas bills the other day and it seems we were averaging 16K KWHr annually before Brink and it is in the 11K KWHrs afterwards. That is a 5,000 KWHr a year reduction helping the environment and a £500 saving a year for my pocket. So the payback for my DIY install at £3600 will be ~7 years. Just wanted to share.

I am wondering why you can't answer that question for yourself by looking at your Building Regs Application? Our BCO noticed that the roof on our piggery is quite small: 20 sq m. She suggested putting the outflow from the gutter on one side of the piggery into the foul drain from our wetroom. The resultant saving in expenditure helped cover the cost of the BCO fees. My direct answer to your question is: IF the outflow from the roof is small, it probably doesn't matter. Ask the BCO when she / he comes on site. The rest of our rainwater outflow was planned for and set out in our B Regs application. Maybe your SUDS (rainwater) plan is tucked away in an Appendix to your application?

Don't forget to allow for the frame but yes the frame can be fixed to the studs

If you have a ASHP, you may do better to remove the iBoost solar divert completely. Run the ASHP at times of max solar and rely on the battery to smooth out the supply to it, and you'll get the benefit of the ASHP cop. (With current pricing plans, where import is only twice the price of export, this logic can now apply even without a battery)

Wow, what an explanation @Iceverge. Thanks man, and you are right, my daughter and fiancé are my life and I never thought I would have kids. I guess 40 isn't too late to find someone that's right for you! And I could never have dreamed of having a house like this, incredibly lucky to have bought a house cheaply in a good area a few years back and the prices rocketed because of it being in a desirable school area. Then meeting the other half who had done similarly. So in answer to your points: 1. You like the house and the area. Absolutely, We bought the house in March 2022, it is a dream. Location is almost at the top of a low lying hill but 2 fields from a light aircraft landing field. Not noisy so not a concern. however it is mighty windy. 2. It is sufficient in size and layout for your needs. I moved from a 800sqm house to over 2600sqm so yes we have space for the three of us! 3. A budget for a knock and rebuild is completely off the table? At the moment the extension is only a en-suit, dressing room, with laundry and cupboard, we don't need it to be glorious, but we do need to improve the icy cold in there. 4. It suffers from poor ventilation. I have a manrose MF150T to go in. enough draw to inflate a hot air balloon. 5. You have lots of drafts, lots of outside doors, lots of sliding patio doors. (Notoriously draughty) Main bedroom is patio sliding door, its going to go and become a French door, We have the orange shutter door between the bedroom and bathroom and shutters over the bedroom door as well. the glass in the en-suit and dressing room i think is less then half the cold issue, the uninsulated roof is the pain. 6. The house has awful thermal bridging, especially the extension with all the steelwork etc. the structural poles, are literally acting as air-conditioning units on lower than low, with the wind blowing past them they are drawing the heat out of the place. 7. You are relatively confident regarding DIY etc I fully stripped out my last house and redid plumbing, kitchen bathroom, some wiring and had it certified, so happy enough. also a mechanical Engineer in oil and gas so yea im confident i can do most things. 8. You need to live in the house whilst any work is ongoing. Yes, there is a main bathroom so the dressing room and En-suit can be out of action for as long as needed. 9. The house swallows heat like there is no tomorrow given it's large outside surface area vs internal area. (form factor) 100%, especially the extension. Main house with stone walls actually retains the heat well. 10. You need to live in the house whilst any work is ongoing. Yup 11. You will be able to afford over a few years to get it to a good standard. Just not in one go. Yup 12. You're off the mains gas network? No mains gas or sewage. we have gas only for the kitchen hobs, and a septic tank. Solar on the roof, intention is to get more and batter storage independent of the main house so as not to affect the feed in tariff. I don't know much about Bregs, especially in Scotland. However in practice it's unlikely anybody will stop you. Tell the neighbours how bad it is, with the baby etc and they'll be lightly to support you rather than call the council. The neighbours are 3 fields away and we are surrounded by a fence line of 200 year old trees. i dont have a clue where to start with who i need to speak to regarding planning other than the council 1. That flat roof has to go. Take it down and scrap the lead. Erect a proper pitched roof integrated into the original house. Do you mean to the same height as the main house roof? What would be the benefit of adding this? Assuming you have at least 10 deg pitch you can use roof tiles which are cheap and durable. 8% at most currently and we have a velux in the main house roof over the top of the flat roof to give light to a rather dark hall way. we would need to account for this in a full pitched roof. and cost I have no idea what this would be. Max i could rais the roof to the house side would be 100mm. which should give a greater % run off. Leave at least 600mm overhang at the gables/eves. Insulate it all with 400mm+ of insulation. Rolls of mineral wool are cheapest but a blown one like cellulose or Glass Mineral Blowing Wool will be easier to fit and re settle when you put in ducting, pipes and wires at a later date. Would hard insulation be better, I would rather spend more for something better if we are retaining the flat roof... 2. When budget allows strip the original roof and with a bell cast extend the eaves and gables at least 600mm also. Sorry, I'm no building expert, what is a bell cast? 3. When the money allows for new windows and external insulation go ahead and do this, You can do one wall at a time if budget is constrained. Take the insulation around the outside of the steel poles and existing stone walls. You can continue living in the house while this goes on. Install the new windows in the insulation layer. I guess I have to ask, will I need planning for this? I assume I use external hard insulation and then roughcast onto that. W cannot insulate the stone part of the house externally as far as I know, it would dry out the stone too much and stop the house breathing. I know I can insulate internally with a fibrous board and lime plaster render though as I helped family do this to their home. Good quality PVC are fine, compression seals are vastly superior to brush seals so avoid patio doors, bifolds and sash windows. Absolutely 4. Install some kind of ventilation system that draws air out of all wet rooms continuously and vents it outside. This can be done now, a decent inline fan, a silencer and some ducting would be enough to get you started for a few £100. Only thing I'm certain about, Ha ha link to the house to give you a better idea of it all https://www.facebook.com/ResidenceEstateAgents/posts/6613161455421700/

Where's the extraction for the 'bathroom', and vapour barrier? Those look to be regular plasterboards. The metal posts can be clad with either Compacfoam ( 20mm minimum thickness ) or Marmox insulated boards ( 6mm minimum thickness ). The new windows can be made smaller to fit up against these products.

Sorry, but to my (engineer's) mind, spending what might be a great deal of money on high performance double (or even tripple)-glazed windows only to bang a load of holes straight through the frames is perfectly insane. If you are on a very tight new-build budget you are probably right and it might not be worth it but if you have an air-tight house (and have paid significantly for the privilege) MV is absolutely essential and if you are going to do that then adding the HR is not going to add hugely to the cost so you might as well have it, too. For old masonry-built properties *undergoing extensive renovation* MVHR (or the MV side at least) is 100% worth it just to deal with issues of damp ingress through dodgy walls and foundations, particularly if some idiot has clarted the outside with cementitious render (and/or non-breathable paint). Those of us who live near busy roads would also benefit hugely from MV for air quality and noise abatement issues (not having to have trickle vents). Installation is certainly DIY-able which should keep the cost under £1k for a small house. I would *strongly recommend* anyone who buys an MVHR unit gets one with 'summer by-pass' otherwise you will still be recovering heat from your expelled air in the middle of summer and warming incoming fresh air making the inside of the house unnecessarily warm. In general, I could not disagree with you more!

I think most of it's written up in my blog here. All I have are two wireless room stats, one for setting the heating on temperature and one for setting the cooling on temperature. They are low hysteresis stats, +/- 0.1 deg C, so provide the fine level of control needed to reduce overshooting the set temperature. The manifold is a standard Wunda one with all the ports commoned so there are no zones (no point in zones, as the heat input is tiny, and rarely needed). The Wunda pump set and remote sensing thermostatic valve does a good job of running the floor at a low enough temperature, unlike some others. There's a need for valves to shut switch from heating (where the ASHP heats both the floor and the buffer that pre-heats hot water) and cooling where the ASHP cools the floor but the buffer is isolated. I used motorised ball valves, because they give a guaranteed 100% shut off, unlike most central heating motorised valves that don't close 100%. This is important as you need to be able to completely isolate the warm buffer (35 deg to 40 deg C) from the floor cooling (around 12 deg C for us).