Thorfun

I stopped writing the blog once the internal work started. I was just too busy doing the work to carry on writing about it! headlines are simple. follow passive house principles. a continuous membrane layer around the external walls of the house and taping all windows and doors. I did a lot of reading on this forum as there are many knowledgable folk on here who have done it all before I even started down our self-build route. my first hint is to do a search on here for Tony tray. get that right in the design stage and the rest should be simple. my second piece of advice is if you're going for a warm loft then consider a cut roof rather than roof trusses. even with attic trusses we had it was a real pain to maintain the airtight barrier up in to the loft and around the trusses. with a cut roof it would be a lot more simple. this might be a good place to start https://passivehouseplus.ie/magazine/guides/the-ph-guide-to-airtightness? then see where your research leads you. I guarantee it will be a rabbit hole but you'll come out of it wiser and with a plan of action.

Are you sure about that? His senses tell him that other dog/horse/cow shit is nice to eat. 😂 Belt and braces! Tape everything meticulously. 😉 i’m sure it’s documented on here somewhere. I’m out and about at the moment but will write something up later for you if you want.

it's lovely! 🙂 very few external noises but we live in a very quiet area surrounded by trees (drone photos on my blogs will attest to that) so I might not be the best person to ask. although in the old pre-fab bungalow the dog would bark at the slightest of external sounds or if the neighbours across the road shut a car door etc. now he doesn't react to noises until someone actually knocks on the door. so the sound reduction is much improved over the shitty little bungalow if that helps! 🤣. I don't know how just using PIR would've been to live in I just didn't want to take the chance and, as we installed all the insulation ourselves, using glasswool in between the studs was a lot easier. if you speak to an insulation manufacturer (you'll need to choose one that does mineral/glass wool AND PIR they will do a condensation risk analysis on your wall build up for you. then the risk is put on their shoulders. We attached our IntelloPlus on the inside of the PIR so all our insulation is beyond it. I did that as I was paranoid about off-gassing of the PIR in to the house but I'm also convinced it just makes the condensation risk reduced and simpler to calculate.

@Pocster I don’t understand about you needing a spread to re-plaster after cutting a square of plasterboard out. Surely you just put the same square back in and then just easyfill around the edge? 🤷‍♂️ glad you got it sorted though

Wish I’d known about these before! But with nuts as big as @Pocster I man’d up and did mine free hand.

Crack porcelain tiles? I don’t know if that’s possible. It’s hard enough drilling through with diamond bits! that bit you linked will do the job nicely. I used the Erbauer diamond bits (8, 10 and 12mm) and not a crack in sight

Yes but bear in mind that some architects are wed to Kingspan and specify it without extra thought. may I suggest speaking to some TF companies and asking to visit previous builds and talking to the owners? MBC do a glass wool/PIR wall that will suit your needs and maybe all you need is to see one in real life. Do your research and then tell your architect what you want. It is your house after all!

+1 i used Jeremy’s heat loss spreadsheet and airtightness had a much bigger impact than U-value. iirc 140mm frametherm 32 (other manufacturers are available) and 50mm PIR gives a U-value of 0.14. If I was the OP I’d be looking at that with a 25mm service cavity and not bother with the internal OSB layer.

They’re run perpendicular to the timbers to reduce contact points as they’re mostly for reducing impact noises. so you could run horizontal battens across the TF and then run the resilient bars vertically. But then you might as well run vertical battens and horizontal resilient bars and can run cables behind the bars!

thank you. my first time fitting guttering. I was very happy with the outcome. 🙂

zinc guttering isn't necessarily stupidly expensive! I fitted zinc gutters to our place and, yes they're a lot more than plastic, but totally worth it and not amazingly more than aluminium guttering. some pictures and details of where we got ours from in

We had lots of compromises and at the time it feels like a really big deal. But after a while you just move on and then it’s like it always was supposed to be and you wonder why it seemed such a big deal at the time! I know I’m not the only one on here to experience that either.

Nice idea. Could potentially look at a rain chain running in to said potted plant?

or is it the cement particle board? I think the external build up looks different to most timber frames I've seen. definitely different to ours! from out to in we have vertical timber cladding 45mm batten and counter batten breathable membrane osb 140mm timber with 140mm frametherm 32 80mm PIR AVCL (IntelloPlus) 25mm battens 12.5mm plasterboard skim I pretty much copied MBC https://mbctimberframe.co.uk/closed-panel-wall-options/ didn't read @IanR's response before I posted. he got there first! 😉

we have 4 ovens. if running all at the same time there's no way a standard 2.5mm ring would handle it. each oven is on it's own cable and RCBO.

+1. for our induction hob we needed a 10mm cable. that's one chunky (expletive deleted)!

the outside membrane needs to be breathable. the layer inside the insulation needs to be airtight. think you've got them the wrong way round? at the very least get an interstitial condensation analysis done to ensure that moisture won't be trapped in the wall nor in the house!

just be aware that trying to fit drywall backboxes to that thickness will be tricky or require more expensive backboxes. you would be wise to cut bigger holes in the OSB before plaster boarding (or even just leave a strip empty of OSB at socket height. trust me, it's a pain to try and cut out OSB/ply after the fact without wrecking the plasterboard! my other comment/concern is the benefit of the OSB? yes it will make the walls more "solid" but is 11mm OSB enough to hold shelves etc? also OSB is expensive! 25mm battens are cheap. and as @Kelvin said, if you're using the OSB as an airtight layer then you're penetrating it and making it pointless. personally, I would forgoe the OSB, use 25mm battens and use an AVCL as your airtight layer. can then also wrap that under the ceiling to maintain that airtight layer. and finally, you don't need a cold loft! you can insulate between the rafters to make a warm loft and carry the airtight layer around that. means anything that's stored in the loft is nicely inside the insulated envelope and any MVHR or pipework running there won't be cold.

Only 11mm service cavity? Are you sure that’s enough? I presume your cladding is horizontal as well? If so can you reduce the battens to 25mm? we did 140mm frametherm 32 equivalent glass wool between the studs and 80mm PIR internally to get similar U-values.

Don’t know about 150mm but we used the 140mm soap bar blocks for our CLS timbers. https://www.dwnye.co.uk/shop/stowells-concrete-soap-bar-blocks-140-x-100-x-440mm-132-blocks-per-pack probably not much use for 150mm timber though unless your ok with a 5mm overhang each side.

we also had a balcony that was causing issues with height and finished floor level. the architect's solution was a hybrid roof in that area. we had an interstitial condensation analysis done and it was ok. it was the only way to get a decent level of insulation. initially they'd specified vacuum sealed insulation panels but they're stupidly expensive and very hard to work with. so the hybrid solution was cheaper and gave similar levels of insulation.

ahh...ok so yeah i understand not wanting to raise it further! ours was a floor level window so raising it 300mm or so wasn't a big deal. our roofer recommended the Alwitra solution and he raved about it. for me, i got a 25yr insurance backed guarantee so that was good enough for me! happy to let someone else make that decision for me as i had plenty others to focus on

our roofers used OSB with the Alwitra VSK membrane.

we had this situation. the window as designed would've been below the level of the green roof. we had to bite the bullet and purchase a new window and raise the wall to bring it up. but probably easier for us as ours was timber frame so i just built up the frame to the required level. we couldn't return the window that was too large so we cut a hole in a wall elsewhere and fitted it there. now we wouldn't even know it wasn't part of the original design!

@ETC is an architect