Thorfun

easily done. annoying swmbo that is.

and then who would make us laugh/would we laugh at* on this forum (* delete as applicable)

yay!!!!

who will you leave the walk on glazing to if that happens?

happy wife, happy life

I'm no expert but if you don't have any insulation then surely your EPC will be a lot worse that a "C"? hopefully someone who knows what they're talking about will be along soon.

We're slowly working our way through our self-build lighting design and I'm using Dialux Evo (https://www.dialux.com/en-GB/) software. it's very good. maybe you should give it a go and then you'll be able to try lots of different lighting to get the effect you're after.

did I also read somewhere that for low tog carpets it's best to run the UFH pipes closer together to get more heat per m2?

very nice! now I'm sure we made the right choice seeing yours. just got to build the bloody thing now.

we've gone for a red door! we think that with the black cladding and anthracite windows it should contrast beautifully. ?

wow! sounds complicated. hopefully our basement won't need such protection. I am also worried about losing room space. it's not so bad in most of the rooms but our plant room is in the basement and losing 100mm from that could mean things won't fit! thanks for the response. when I get nearer to the time of finalising our basement detailing if I have more questions I'll start my own thread on the subject. sorry again to the OP for hijacking the thread.

sorry to hijack the thread, but out of interest @nod how would you create a service void on those walls? our waterproofing expert company has suggested this form of internal waterproofing (the Delta system) for our basement with a drainage channel to a sump pump but it looks like the only way to create a service void is to build another internal wall with access points for maintenance and then batten on that. They do suggest you can dot and dab plasterboard straight on to the membrane, so could you potentially dot and dab osb and then attach battens to that for a service void and then plasterboard on top?

another that has gone for RAL 7016 here. we're having Shou Sugi Ban larch cladding (aka charred larch) and so feel the black and grey will go together nicely. a lighter or brighter colour would, for us, make the windows too contrasted with the cladding. I'm not worried about it going out of fashion as I'm not building the house for others or to be 'on-trend'. it's being built for us and we love the look of Anthracite grey windows. ? and, just like @canalsiderenovation, we are having white inside but have gone for Norrsken windows instead of Internorm.

GHG is on my research list too. Just one of many subjects on a very long list!

yeah. that's what I gather from the reading I've been doing. I have a neighbour who is a plumber so I'll be popping around to see him and ask about DIY installing the ASHP. as with anything it's only the lack of confidence and not wanting to screw it up that is holding me back from just doing it all myself. that and I want the house to be finished before 2030. ?

understood and agreed. I am already paying for a full thermal modelling report which I'm hoping won't be too far away so I will have those head demand calculations soon. until I get those though I'm working on the results from Jeremy's spreadsheet which all seem to say are pretty darn accurate! I'm still waiting for a couple of companies to quote but at the moment it's looking like RHI just isn't worth it.

thanks @joth. I will read through that document in detail. I also have had a couple of other quotes and neither of those companies have said that all rooms need to be heated so I think these guys are wrong (or simply mistaken), as your research has showed. what I'm also finding is that the MCS/RHI heat loss calculations are shockingly bad! I've used @Jeremy Harris 's spreadsheet and it comes out at worst case scenario an 8kW ASHP @ -10oC. but all the MCS installers have said I need a 14kW ASHP! after speaking to one of the installers we figured out that the RHI heat loss calculations don't take in to account the efficiency of the MVHR. once he added that in my requirements suddenly went down to 5kW @ -2oC. that's a big difference. I'm seriously looking at forgetting RHI for the small amount we'd get and just getting a plumber to install the ASHP. for a highly insulated and air tight building the RHI just doesn't make sense. it would be better for me to aim for a lower SAP rating to get more from RHI rather than spending money to get a high SAP rating. just seems completely balmy and backwards to me.

I had an interesting conversation with a renewables company that said that if I wanted to claim RHI payments then every habitable room in the house needs to be heated by the heat source, ie. ASHP in our case. I asked about Passivhaus properties where heating upstairs might not be required and was told that if a room is not heated by the heat source then the property doesn't qualify for RHI. does anyone who can disseminate the minefield that is RHI let me know if this is correct? sounds like a crock of excrement to me and they're just trying to sell me UFH on the first floor in order to some RHI payments. I still haven't decided if I'm going down the RHI/MCS route yet for ASHP (or Solar PV) but I was generally thinking of not having UFH in the bedrooms and having electric UFH and towel radiators in the en-suites on the first floor. and wet UFH from an ASHP in the basement and ground floor. so if I did go for RHI then the electric heating and lack of heating in the bedrooms was mean we wouldn't be elligble anyway.

thanks @MrMagic I'll take a look. I haven't started researching the different refrigerants yet but it is definitely on my list!

just as a quick update, I found the spec sheet for the Mitsubishi R744 ASHP and it's COP is pretty rubbish. so I'm not bothering to look at this anymore and will focus on a standard R32 ASHP. data sheet attached fyi. Ecodan_QUHZ-W40VA_Monobloc_Air_Source_Heat_Pump_Product_Information_Sheet1.pdf

bumping this topic as I've been informed by a potential installer about the CO2 refrigerant and was wondering if those that know have any more information or updated opinions in the 2 years since this topic was last raised? @Nickfromwales would you still not quote for it? we're going for UFH so don't need the high temps for DHW so should I not even bother considering it? or will it be Uber-efficient when running at UFH temps, even more so than an RC32 ASHP?

@Mako sounds like you need to spend some time reading the blogs of various members here. plenty of Passivhaus examples there. will give you a great understanding of what is involved and how the folks who keep the blogs approached every area of their build. I have found the information invaluable and often refer back to them when researching the various areas of a self-build.

we found cardboard boxes are better as they're stiffer and can be more easily removed during the day. ?

I asked the same question when I first joined but then I realised that it was in the forum guidelines all along! https://forum.buildhub.org.uk/guidelines/ which I'm sure every member has read, right? ?

ha ha....flying by the seat of my pants really! but I'm fortunate that I spend all day sat in front of a computer so a large portion of that is spent on this forum trying to learn from everyone. so if it seems organised then you all are teaching me well. ?