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In 2022 I installed a heat pump in a property I was renting out and in 2023 moved in there myself and have now lived though a whole winter with the heat pump as well. I explain on my blog why I did it, how much it cost, and what issues there were, and so on. It's 1,000 words long, and at the below link. I previously did two threads about the cost and environmental impact of the install on this forum which are linked to in the post below. I hope this helps and let me know if anyone has any questions. https://foxesinchile.wordpress.com/2024/04/09/my-heat-pump-experience/

I have seen primary reasons somewhere, so you may need to hunt around a bit. Some of that can be attributed to lower smoking rates and fire resistant furniture (was in the 1980's that the legislation came in, so most of that furniture is now discarded).

Was it installed off centre to allow the shower door to open?

It seems there are several different Altos out there. They have just turned down my request for rads, UFH and a TS in parallel with the HW tank, saying "I have discussed this with my technical director, and we don't have a heat pump that will permit this type of set up and unfortunately this type of bespoke design isn't something he wants to get involved in." So I am assuming that Mitsubishi don't provide the necessary control options, at least not natively. Still waiting for a final Vaillant quote, which was promised as top of installers' list well before Easter.

Can you put numbers on the elements?

Rarely any issues with a 5 kW ASHP heating a 250 L tank. I'll admit a faster reheat time would be nice a handful of times a year, but then I just hit the immersion for an hour to help speed things along. If you want to keep your ASHP temperature low and your COP high when doing DHW, go for a bigger tank than you think you need.

Don't know why you'd need 11kW for a 200l tank, in reality you never fully empty a tank to ice cold and reheat to full temp. Just set hot water on 24hrs and the lower setpoint to 35c. We've never had issues with our 9kW heating our 300l tank.

Does have a whiff of that - ask them which university gave them their degrees in Thermodynamics perhaps. I think that all these companies have spreadsheets which don't look at the thermodynamics at all but just at demand and the double the size of the heat pump. There must be a sweet spot where the cost to them of the bigger heat pump is proportionately lower so more profitable and they can sell it you as faster reheat times. However 11kW going into 200L starting at 10 deg and going to 50 deg C with 80% efficiency is 1h 3min 25.2sec so that bit is about right and if you go down to 8kW it will be 1h 27min 12.6sec. Then you are into worrying about modulation depth for great chunks of the year anyway as @JohnMo says.

A combined, MCS heat loss spreadsheet and shite in and shite out from contractor. Cylinder temp does not need to be above 50. UFH will be closer to 30 to 35 I suspect. If your max heat requirements are close to 3kW, you really need to look at heat pump turn down as that is a big pump. Biggest issue will be required flow rates for water. 3kW only requires around 10 l/min, you may have to manage 20+?

Won’t affect material costs as much as you’d think unless suppliers have over stocked. A lot of stuff is imported. It will reduce margins however and labour rates. We’ve built in the inflationary year but are still well under £2500/m2

It's not a matter of trumping. The planning permission still applies. If the visible change is significant or arguably so, I tend to send a courtesy message to the planners, for the record. I've never had a response, which i deem to be acceptance, and have been happy that it closed off any future issues. This is also probably preferable to the planners than a formal change, which takes their resources. It's up to you.

We contracted a builder, so costs are higher than true self build. But it's over 250m2, almost passivehaus, triple glazing etc. At the end of the day we ended up about £2.5k/m2. Simon

Agreed - we've got a mix of wifi and zigbee. Isn't the supply for POE a bit 'juicy'? I wonder how these compare to a Loxone system? Simon

Plus 1 Planners are only interested in how it looks Just to add I would get or alter your SE drawing and calcs To save issues down the line Should you ever decide to sell the house

No wires run in yet but easy with the trunking. Whole house is wired to use least WiFi, I have even hard wired the amazon fire sticks in.

>>> Still looking for a better option ideally din rail mounted. Take a look here: https://uk.rs-online.com/web/c/relays-signal-conditioning/relays/timer-relays/?pn=1&applied-dimensions=4294883333,4292117068,4294571726&sortBy=P_breakPrice1&sortType=ASC RS won't be the cheapest, but most of the stuff they sell is professional quality. You'll probably need to apply a few more filter criteria, check the datasheet etc to make sure it has the continuous cycling function you want. In particular, check the contacts are man enough for the job ('max current') - suggest 3A min and beefier if you want long life.

Thanks both for your help, really appreciate it. Feel ready to tackle this now, wish me luck haha.

We paid £138/m3 for 27m3 of C35 concrete (plus vat which we'll get back) so about £3K and £700 for a line pump plus two operatives for a day.

🤣 Most online "ready-to-go" kits for the Loxone Power Supply & Backup seem to be 12Ah with a couple of 24Ah. I'd note that the 24Ah one weighs 26.5kg, so your potential 145Ah solution is not only going to be expensive, it's going to be bloody heavy too! I'd get the lights in first, then see what the actual draw is when in normal use, and what would be an acceptable dimmed position in the event of a power cut and then go from there.

I wouldn't do it. Many people would love the extra interest that the slope brings. It looks as if it slopes southish, picking up more sun too. There's lots of scope for interest with shade loving, easy care plants to the left and keeping the right for lots of sun. By all means flatten a small area where you would like to sit or kick a ball about.

Dreamingthebuild...everything you type seems a little "asking for a friend"! And possibly just trying to plug your own YouTube channel. I doubt anyone would have a problem with this it just all sounds suspicious the way you are writing it and asking questions!

The topic is about PV inverters so no personal data, no banking details, pics of the wife etc etc. If someone hacks your inverter just disconnect it from the internet, reset to defaults and fire it up again. Fret about all the other connected stuff if you want but I don't think your inverter being hacked is worthy of any worry In terms of avoiding future charging, just don't buy an inverter that needs an internet connection to run. Seems that there's likely none out there that do need a connection so I can't see any post sales charging being "just round the corner"

@NailBiter and anyone else trying to register on Solcast, the site is quite confusing. The registration page has 3 boxes with text in them for each type user user. Inside each box, there is a hyperlink but this link takes you to an information page about the service for that type of user. So you end up in a loop. You need to click anywhere in the box for the different user types - it's not obvious that the box itself is a hyperlink. I've suggested to them that this is a little confusing. Simon PS @NailBiter thanks for your offer to help by DM

Ventilation, ventilation, ventilation, stick a living, breathing, cooking person inside a box wrapped with plastic and you are going to get damp and mould.

There isn’t a minimum. With standard internal doors being 1981mm plus their architraves and external window heads normally being 2.1m above floor level, ideally you want the ceiling to be at least 2.15-2.2m.

Correct, at least in England. There was once a minimum room height, but it was removed from the regulations many years ago.

Absolutely this. Putting your house, things in it and other things you have at the mercy of organisations whose only motive is profit. Have we all forgotton rings little expoilts. Once you invertor is built in, whats to stop them taking control, and demanding £5 a month for having it working? Im afraid its a no from me. As Nailbiter says, without consumer pushback, we will see more and more of it. Sadly, i doubt we will see consumer pushback, people seem completely relaxed about it.

Mostly I would say labour costs and profits.. There is a big downturn in work. some contractors are very quiet and some are tendering at very low margins to keep turning over. That affects the wages of all operatives

Some prices are definitely down on the peak. Rebar, framing wood, and osb are good examples. Stuff that is still high, concrete, aggregates, labour, windows. I noticed builders are now quoting in the £2000 to £2500 per m2 range last time I checked it was more like £3000 to £3500 per m2. I don't know if this is because prices have fallen for materials or if they have reduced a large buffer they had for jobs because it was impossible to predict material prices and availability. Overall I am happy I have waited the year before starting, but who knows another war or escalation of the current one could cause prices to rise again. I also don't think inflation is completely gone and as soon as interest rates drop I think we might see more inflation. One thing that is definitely better is the availability of product and the willingness of suppliers to compete.

There's lots of things going on with house construction. Unfortunately there are loads of snake oil salesmen and manufacturers sales claims being treated as science. Most people rely completely on gut feeling. Amusingly this covers the entire spectrum of building types. Starting with the guy with the reflective wrap around sunglasses. " It was first used by NASA don't you know, ,researched in zero gravity, AI and smart watch connected. It will predict the hot water demand using quantum computing" In the middle there is the trusty local builder, "my dad did it this way like his father before him, hammer a 2 X in there and an bit of mortar and she'll be right." "Stick with what you know" At the other end is the hairshirt hippy. "Straw bales and reclaimed beachwood, gotta let it breath MAN" "Align the floorboards to the energy lines MAN". "WiFi gives you cancer MAN". Of course they're all right........and they're all wrong. It's a roll of the dice really........ They rely on belief and faith and it if works for them, I've no objection. However I would be wary about spending my cash on what someone else "believes". @Carly Lawson if you believe that durisol is the most environmentally friendly choice (I don't know BTW) and having that feeling is enough for you, then go for it. However, if you want to actually build the lowest environmentally impactful house then that's a different thing.

Then let if overheat. Back in '86, I did some composite plastic samples for material testing. One of those samples was purposely made incorrectly (way to much hardener). Popped them on the testing machines (tensile, compression, bending and vibration) and watched them explode. The one that was purposely wrong failed very early, except for the hardness testing, it was way harder than the others, which accounts for the spectacular failure of the other tests. (I did my apprenticeship in a company that made testing machines)

The only issue I had was the pan to gantry fixing where it involves flimsy looking plastic inserts for big bolts. They came loose, but I think it was my fault for being scared to tighten it to the limit, being plastic and porcelain. It's been fine since it was redone.

With 100mm insulation and 150mm blocks you're at 250mm. Why not just build a full fill cavity wall with batt insulation? Alternatively a TF garage with an insulated inner stud and block external leaf.

Is it. At around £100/m3 delivered it must been one of the cheapest materials there is. You can buy standing timber, with the bark, at around £55/m3. Once planed to size and stacked in Travis Perkins, it becomes about £2300/m3. I am adding to this, as I am a bit bored this morning. The embodied energy in concrete is around 2500 MJ/m3 (700 kWh), timber is 5100 MJ/m3 (1420 kWh), the embodied carbon is 360 kg/m3 and timber is 280 kg/m3. Food for thought that is. https://theconstructor.org/sustainability/embodied-energy-building-materials/567108/

So far i saw a hilti jig listed at ' from £130' but the actual quote is £1200 for a week minimum 'because it is a crosshire". Won't be going there. Another national hirer says £320 per day or £420 a week, and i know they don't do discounts. Now have a definite offer of £360 for a week. Will try one more that i'm told may beat that. If I am doing 5 or 6 holes I'm prepared for this cost rather than a much more tiring and vibrating time with a hand held. The control may save on blades too. As @Gus Potter excellent essay above, the investment should be worthwhile in either saving construction cost or designing particularly to suit the situation. How many slabs are uniformly as thick as designed? Not many. It's difficult and concrete is expensive. How many fail because if this? Not many, as long as the quality is high. Btw in no particular order these merchants are Travis P, Brandon, Alliance, HSS. The tools are Hilti or Husqvarna.

And, if you build the house well enough, with enough insulation and air tightness, then as many of us have proved (even up here in the Highlands) then you way well not need any heating upstairs, just UFH downstairs.

Slightly off topic but 45 is too high for an optimal new rad system. My average this year so far is around 37 with 100% rads. Design temp was 40.

Spray foam depends on a few factors, vapour open or vapour closed. Retrofitted to a cold roof rafters to help hold the roof together is bad as pointed out above. New build no issues, as you can design for it. Interstitial assessment is a must for spray foam same, as with any other means of insulation. Scottish regs require us to install sarking boards, these are installed tight together and as the wood dries it leaves ventilation gaps. Above this a suitable breather membrane is installed. The foam used is vapour open. So any moisture can migrate outwards. The slates attached to the sarking boards, provide a ventilation space. Below this it is ideal to install a vapour closed membrane.

+1 The problem with spray foam in roofs... Water vapour from the house that gets into the loft must be ventilated out or you get condensation and rot. Some roof membranes, particularly on older houses, are vapour impermeable. This means it can't escape through the membrane so vents are provided at the eaves. They are designed so that air goes in one side, across the loft and out the other side taking water vapour with it. When conventional sheet insulation (PIR, PUR etc) is installed at rafter level it's normal to leave a 50mm ventilated void between the membrane and the insulation. Air goes in the eaves, up this void and out at vents at the ridge. If you just spray foam onto the membrane there is no ventilated void. No way for the water vapour to escape. There is a risk of condensation causing the raters to rot. In some houses there is no membrane and the foam is sprayed onto the underside of the tiles and around tile battens, this can also trap water against the battens causing them to rot. If spray foam companies were to fit some sort of tunnel or spacer between rafters to preserve a ventilation gap before applying spray foam there might be a way to use it without creating a condensation risk. Unfortunately the appeal of spray foam is the speed of application and fitting these spacers would detract from that. Scaffolding would also be required to provide vents at the ridge, in many cases the ridge would need replacing to provide vents. Mortgage companies have woken up to the issue spray foam can cause and many now won't lend against properties where spray foam has been used, even if used correctly. This has nothing to do with cans of spray foam used to seal around doors and windows or cavity wall insulation.

Try reading the rest of my posts. The point I’m making is that these costs are eye watering and are padded out with services that need to be completed for a BC application but are being highlighted as if they are “special” services that are worthy of a special mention in a fee break down. They aren’t special and they don’t warrant any special highlighting in a fee quote. As for working for free I do it regularly on this forum - we all do - every time we offer advice we give it for free so why is this post any different? I didn’t join this forum to chase work and I have been approached several times by forum members to complete drawings - and have been offered fees - but in the spirit of this forum I have decided that I will not charge anything but will help where I can. The costs quoted are - in my opinion - high and as I said padded out with irrelevant information designed - again in my opinion - to justify the quoted fee.

@IanR I appreciate what you’re saying about rainwater attenuation in rural settings but something @saveasteading said in response to a comment I made about our situation struck a chord with me. That was something like you want the rainwater impact to be much the same (or better I guess) after you’ve built as it was when it was just a field. As I mentioned, our burn, which is always flowing, discharges into the river Ericht which runs through Alyth. We’ve lived here for two years and have seen how high the water level quickly gets over the winter. It’s flooded out the market square a few times. I wouldn’t be comfortable if I thought I was contributing to that.

Absolutely possible given that you're heading to a very low temperature. Enjoy an installation that will perform well. Bloody heat pumps never work blah blah etc. 🙂

😂 I am planning two bridges!

>>> I’ll cross that bridge You're planning a bridge too ?

Yup. Need a packed lunch to go from the basement to the top floor lol.

Christ on a bike….those costs are eye watering. I’d do them for half that!

I installed a new gas combi for an old biddy and her spinster daughter. She had me go back, complaining that the living room would not get warmer than 21oC. My friend and I arrived and walked in, and within 60 seconds were both lathered up with factor 50 and stood there in pants and socks, as it was like a sunny day in Dubai! The daughter had bought one of these weather station things from a petrol station and sat it on the marble fireplace, which had a gale blowing up it, and was on an ice cold outside wall ( mass produced bag of shit house btw ). I picked it up and placed it on the lady's coffee table next to where she was sat. As I was getting my arse chewed off about how the old boiler ( same kW rating, same radiators etc but now all flushed and with new TRV's ) was "so much better than the new one"...... After 5 minutes I pointed to the weather station doo-dah and it was showing 24.5oC. We replaced the central heating system, but what we couldn't replace in that house was the lady's central nervous system