Andeh

MVHR are not 100% efficient so do reduce things, they are just "less bad" then trickle vents and extractor fans.

Reminds me of offering a dozen thick paving slabs via facebook market place, insisting buyer collects - easy way of getting shot in urgent fashion. What I failed to clarify was 'buyer to load'...... I was not a happy bunny as the walrus of a women watched me load. Fool me for being too nice.

That's an interesting idea, class it as a storage platform/loft space? Would this just be a call to BC in advance to seek their approval of it? Thank you very much!

There are some bits I want to do to the house with the builder, but avoiding building control's scrutiny (!!). Some tiny bits like removing a banister off low steps, installing a door to garage that doesn't meet head clearance heights etc etc. Bigger though, is i want to install bedroom mezzanines due to smallush bedrooms which have very high ceilings. These will have staircases that don't meet building regs. This will mean cutting back the plasterboard to the brick, and installing "mini" staircase (from Stairbox) before recarpeting and replastering the Mezzanine in. Ideally I would prefer to do this before the builder installs plasterboard and carpets, but after building control sign off. To save cutting up brand new board and carpets!! What is the trigger for building control to complete final inspections? Could they do it before Carpet and plasterboard is done? Any other unforseen consequences, namely builder & VAT exempt build?

Due to the nature of our 240sqm bungalow, and all ceiling heights being average of around 3.5m+ and it being ''H'' shaped with kitchen, lounge etc on one ''wing'' and bedrooms & bathrooms on the other ''wing'' our builder's initial thoughts are for two MVHR system. He is out seeking quotes, with a request from me to try and make it work as a single unit. Has anyone else gone through a similar challenge? Did you go for 2 x smaller or 1 x bigger unit? Anything worth being aware of in making the decision (other then 2 x energy costs and 2 x filters)? Ducting looks to be 75mm semi rigid pipes, what is a good safe ducting to look out for in the returned quotes to ensure best performance? Thanks,

Sorry for reviving an old thread, but we are in the same boat here. Being recommended two small systems, when I would much prefer one larger system. How did you get on in the end? Did you go with two smaller systems?

I guess because a very large portion of electricity is generated from fossil fuel power stations which keeps the prices linked, bur electecitiy has the mark-up due to converting fossil fuels to electricity. Long term though, with new nuclear and more renewables should soften the link, and eventually the UK gov will load up gas prices more so then electricity to force people to convert. It's all a good long term strategy, and the right one for the country....but I'm still going mains has boiler over ASHP because mid term it will still be cheaper. We will just design it so an ASHP can be installed at a later date.

Has anyone heard of this in the UK?

We are looking at cladding on an otherwise whit rendered, black windowed, bungalow. Wife doesn't like wood cladding & i don't like the idea of it fading in time. We are therefore looking at ''slate'' cladding. We have found Z Stone we like, but it is slightly too 'light grey' when I want something closer to 'black' - i think. Z Stone is in the build spec, I just want to make sure we dont overlook something else out there. Has anyone come across anything worth suggesting please? thank you,

nod - I think you need to be clearer when you tell people you came in at £800psqm - because you did a huge amount yourself I believe? Far more than even the most enthusiastic DIYer would be able to do. Otherwise I agree with your statement, - £1500 if you are very hands on & involved with a low-mid spec, otherwise assume closer to £2000+ psqm for a more standard contractor led build with limited ''hands on'' focus yourself. We are at £2300psqm for a large bungalow to a mid/high spec (though mid spec bathroom/kitchens). Bungalow being prob 25% more to build then normal house. Brick/block, MVHR, very big aluminium windows, floating corner, high ceilings, upgraded insulation (though not extreme).

Fit a solar diverter as has been pointed out, but if you have multiple ovens running for prolonged periods....your electricity bills are never going to be great. Try running your house synced to the solar. Cloudy day today, but clear sky's and sunny tomorrow? Delay the dish washer and washing machine until tomorrow... etc etc

Thank you again all! John - really interesting to hear about your challenges, this is something I am aware of & wanting to avoid...low energy house & sizing heating input accordingly. What kW is your boiler out of curiosity? We would go with a System boiler & large tank, but would be interesting to know all the same. Builder suggesting a 12Kw ASHP for the 240sqm of UFH - pre plumbed package deal from Joules, supply & fit. We havn't discussed gas boiler, and i'm not sure what the equivalence is for a 12kW ASHP unit. Agreed on insulation being the priority - but for us its more of a desire to be top 5% not invest to be top 0.5%. Law of diminishing returns is something we are aware of, but the walls are fixed now (ie built & roof going on) and the wall/ceiling are already up to a good standard. Walls I do regret not upping (didn't know enough at the time) and will look at PIR Plasterboard, but one of those things...too late now!

Thanks Tony, yes one thing I am considering is savings made going from ASHP to Gas be used for insulated plasterboard on inside walls.

Thanks very much John, out of curiosity what are your bills with that setup? Any PV?

Would very much welcome thoughts from all, thank you for your insights!

Thanks all, yes the walls are 125mm Knauf dritherm 37, will always be a regret we couldn't upgrade them to 150 cavities but by the time I realised it was too late. Though one option I am debating it the savings going from ASHP to Gas used to request insulated PB for the external facing walls - though due to 3.5m - 4.5m ceilings everywhere it wouldn't be cheap. Floor & ceiling is 150mm Kingspan PIR. I have done the Excel spread sheet as best I can, it is a real abnormal bungalow, in the sense it is ''H shaped'' with the middle bit being the flat roof entrance hallway and two 'wings' being large 10 degree monopitches coming down to the middle flat roof entrance. As a result we have the 'perfect storm' of big floor areas (230sqm ish + garage), big roof areas (250sqm flat roof) AND high walls everywhere (3.2 low side, 4.5m high side)...with over sized windows/glass everywhere.... 3180_s4_100J_Floor Plan.pdf Heat loss calculator - Master (1).xlsx

Original FiT...we have lifted old system, swift replacement of the bungalow below (!) then reinstalling original system like for like to maintain the 'original' FiT.

Final U values of 0.13 floor, 0.15 ceiling, 0.22 for walls. SAP scores are looking to be high 80s, following an 83 score before we increased the depth of floor and ceiling insulation by 25mm (PIR). 150mm pipe spacing. I am going to ask the architect to refresh the SAP calculations to help with this decision, as current one are out of date (due to insulation uplifts) - for both Gas & ASHP.

Thanks Joe, we have 3.99kw of PV, but cant install any more without risk of losing the FiT. Fitting a solar diverter + slightly over sized tank (300L) is on the cards to try and support the DHW.

Just to say 'Hello' to the OP, I am in the exact situation you are . Probably 53% leaning towards gas and 47% towards ASHP. Having mains gas & 250sqm property, SAP of 87 (so less then yours), 3kW PV (due to original FiT limiting expansion).... originally expected ASHP, but with very high ceilings everywhere, builder is walking back on his original ASHP recommendation and is now swinging to recommending Gas. I am still working my way through it all...

We are half way through our new build, a large bungalow with smaller then average rooms (due to 4 kids & guest bedroom needs, but on a budget) but with significantly higher then average ceilings. 4.5m at high side of building, 3.2m at other side of the mono pitch. All brick internal walls. Builder originally recommended we go with ASHP, and proactively included it in his tender price, same with MVHR. At the last site meeting though, he has recommended we drop the ceilings heights to something more normal, as he is uneasy about the warmth of the place with the warm air rising & leaving the bottom half of the rooms feeling chillier. We declined reducing room heights, so he then suggested using a combination of a gas boiler & ASHP to ensure no risk of UFH struggling to maintain decent warmth during a cold winter. My view is this is too expensive & complicated, so its either ASHP or Gas. We are on mains gas... Builder has been 100% faultless to date, and I do trust him/have a good working relationship with him. Going for a gas boiler in a modern home (SAP of around 87) feels 'wrong', but I always felt Gas would be the cheaper option installation & heating wise...just mains gas being so cheaper vs electric. Just keen to understand anyone else's experience of high ceilings & UFH, and whether there is a risk ASHP could struggle on cold days? I am really 50/50, but starting to lean towards Gas just for the £ savings & reliability of turning up the output. Welcome all views, thanks

Risk of Air Con is you turn it on during the day and cool the rooms down, but the MVHR system naturally pumps that cool air out the house and brings back in warm external air? We have very high ceilings everywhere, so I suppose there will be a benefit of the warmer air rising to the top (vents) and being extracted, whilst the cooler air sinks lower? I think i will work on the assumption that on the hottest of days, I will turn the MVHR down/off and turn AC on everywhere. Then when I turn the AC off in the evening, turn the MVHR back on. For those handful of days a year when we hit record temps, ill just add it to my routine of closing curtains to block out the sun, and isolate the air inside the house manually. Not sure what others do in these situations?

Despite being a bit of a nerd, I cant justify full home automation right now. Cost, complexity, other build worries to focus on etc jut mean I don't have the bandwidth to give it full attention. That being said, in future it is the sort of thing I am quite sure I would like to dabble in. Our project is a full build, and the roof is going on as we speak so I need to start making the call now on what we want as final electrical layouts. In my mind, lighting systems & electric blinds are two areas worth trying it for, accepting that video, alarm, climate etc are all systems I am happy to keep as 'dumb' long term (CAT6 to all points gives a degree of options one day potentially). Is there a relatively easy may to future proof lighting & blinds for future home automation? ie tri core cabling between lights & light switches? Are there any ecosystems worth exploring? ie; if for £1000 we could install a degree of centralised lighting controls it is something we would do! Any advice on how to check this? In my mind, the furthest we would go is: 1) PIR in hallways & bathrooms 2) Automatic lowering of blinds at set times 3) Grouping of lights and diming of them Many thanks

Coming together really nicely there! We were due to move in today (!) but roof only 50% done, November now How do you find the black sanitaryware in the bathroom with water deposits/soap scum etc?

Also interested as our build will be finishing in November, with rendering required....