Thorfun

doing mine myself I thought many times that I'd hate to see the sort of job a builder and their labourers would do (not all of them though I'm sure!). the methodical and detailed work we did cutting PIR, membrane and taping I can guarantee that a builder on a price job wouldn't spend the time to do. I'm very glad I did ours ourselves but I wouldn't do it that way again as it was a horrible and slow job.

I would suggest the OP do as @ProDave has suggested with a cut roof. having been through the process of filling our attic trusses with 195mm glass wool and adding 100mm PIR underneath I can tell you it is a pain on attic trusses! in our vaulted ceiling entrance hall we had a cut roof and it was a doddle not having to cut around trusses. but might I also add the suggestion of using very deep trusses as filling will blown cellulose instead of mineral wool and rigid insulation combo. if I had my time again I would do a cut roof with blown cellulose for sure!

the do look rather good! mind tell me/us where you got them from? was it from Topps as shown above or was that just a dig at them and their tiles and display?

I used 90mm ring nails for ours. Was really quick and I used the battens as a climbing frame to reach other areas at points and they didn’t budge. I’d be asking for specifics as to why you’ve been told screws.

Zehnder Q600. i didn't want 2 x smaller units and so the company i was using made the Q600 work with regards to flow rates by using 92mm ducting.

for clarity.....12.5mm plasterboard on EITHER side means only on one side with the linked prosound-soundboard on the OTHER side, right? not 12.5mm plasterboard on both sides with the additional soundboard on one side?

i bought a load of screws for fitting my PIR and battens from https://screwshop.co.uk/ .

did you dig all that with just that shovel and yellow bucket? you truly are amazing!

oh no! what have you done. 🤣

i used this one https://www.changeplan.co.uk/u_value_calculator.php but there are many others as well. there are many knowledgeable people on here for U-values. a large number of them helped me get my head around things in this thread take a good long read in the relevant sub-forum and you'll soon be a lot more knowledgeable!

and then sue him for poor living conditions? at the very least withhold the rent.

i think it all depends on the airflow required and needs to be calculated. we had 90mm ducts specified as our unit was pushing the limits of the area of the house and so by upping the duct size it made it all work.

Could you potentially use those insulated blocks others have mentioned on here in other threads instead of normal concrete blocks? Probably expensive but might be a solution worth investigating?

The tangled webs we weave

welcome. sounds like you've joined the forum in the nick of time! TLDR all your documents (sorry!) but i've a few comments. 1. did you tell your architect you want passive house levels of insulation? if so, and i don't think you're quite there tbh but i haven't run the materials through a U-value calculator, then i would be going back once you've done those calculations and asking why those levels haven't been attained? 2. speak to many different TF companies. you specified a single company above but i would hope that you get at least 3 quotes. we got many more than that and whittled it down to a final three to choose from. 3. did you give the architect a budget to work with? if so then if they've designed a house that is way over budget then they've made a mistake and you'd be within your rights to get them to value engineer it. i'm sure others will chime in. i'm no expert but if you read through our blog on here you can see where we're at with our journey. I might advise that you put the brakes on for a couple of weeks and absorb as much information as possible from on here by going through each forum. Also read up on some self-building books. i found Mark Brinkley's book very useful as a starter to self-building. i wish you the best of luck and look forward to following your progress should you choose to share. 🙂

Take a read of the self build vat forum https://forum.buildhub.org.uk/forum/103-self-build-vat-community-infrastructure-levy-cil-s106-tax/

Your builder is irrelevant! His materials and labour will be zero rated. Even if you got someone else in to do work outside of you main contractor they would zero rate any materials and labour. Separate to that is anything you’ve bought that is valid can have the VAT claimed back.

If it’s for the build you can claim the VAT back if it’s eligible

We’ve had no water ingress through the walls or slab. No internal measures at all. The waterproofing we have comes with a 25yr warranty so I’m confident in it doing the job. interestingly the original waterproofing company we spoke to through the architects specified the internal solution that @pocsterhas and obviously works. Our architect was also ok with that solution. But the company that built our basement always used external membrane and so we changed to that. I do find it strange that new regulations don’t allow internal solutions though. As has been said in some situations external just may not be possible.

I don't know about soaring prices as we had ours built from reinforced waterproof concrete with external waterproof membrane so water stopped externally. so exactly the same as it would be done under the new regulations. seems like these new regulations are to stop cowboys like @pocster doing it DIY style? 😉

TLDR but images g & h seem to summarise it I guess

I used to do this but in the end Jewson always came out with the best price and if they didn't my account 'manager', i.e. the sales guy I deal with, would price match. now I just find what I want online and phone him up and see if he can match it and don't bother with other BMs I have accounts with. sometimes he even beats the online price. but I have spent a lot with them over the past 2 years and have built up a good rapport with him so I think that's important. As @pocster says, a bit of banter and cheekiness also helps.

this is a very slow way of doing it although it does reduce the risk. windows tend to be on at least a 12 week lead time and so you're TF won't be watertight for at least 3 months after erection (depending on when the roof goes on of course). our windows were ordered off-plan and the TF company then built to the correct dimensions. meant we could get the windows in as soon as the roof covering was on without having to wait for the windows to be manufactured. i thought most building with TF did it this way? one of the benefits of building in timber is the accuracy that can be achieved over block and brick.

i should probably clarify that Norrsken arranged the fitters as well so it was all, kind of, in-house. maybe different if the fitters are 3rd party as then it could all become a blame game.

Our window supplier also asked for the roof to be fully loaded before they installed the windows.