matthyde83

Yep ours is all pour meters etc. We’ve located them on/in the garage. Plus taken mains water into there. So we can isolate the bungalow from the garage for demolition.

Understood. So you would recommend thermalite up to insulation layer then a layer of Marmox rather than another thermalite in line.

That seems to make sense... 65mm marmox 0.05, 215mm Aircrete (10N) 0.19. So Marmox is slightly better at 3.3x BUT if it's courses below and then courses in insulation layer say 3 courses the aircrete will be much better.

“far” better sounds like I’m going to make the more expensive choice then…

I'm just finalising my foundation details and I hope someone can help me make a decision... Do I emlpoy Marmox Thermoblocks on the inner leaf at the insulation level or simply use thermalite or similar below. Can anyone help with the potential performance of the two different methods? I expect it to be significantly cheaper to use thermalite blocks. Traditional slab build up of 200mm with 200mm insulation above. Also I've drawn the Marmox block at 215 tall below but it's 65mm so ignore that.

This is directly from my demolition notice...

yep but if I have just 200mm would you go 200mm PIR, 200mm EPS or 100mm EPS and 100mm PIR? 50mm chemical screed

at 200mm though would EPS performance suffice? I know that a lot of people on here have gone for 300mm but I can’t easily get that. Various reasons but insulation on top of slab is my way to go.

I think it’s more popular at the minute with price rises as there are some big unknowns for the builders when they’re pricing jobs. It’s a builder I’ve used before (on a price) and I’ve seen how hard they work / what they class as a “day” so I trust them. I’ll be there at least 3 days a week to oversee. I’m helping order materials so I’ve got transparency there. Ultimately I know I’ll be paying for exactly what I get and it’s my job to build in contingency which I can then keep if not used. So few reasons really but cons are obviously not knowing exactly what it’s going to cost!

Great thanks for that… yep been through those. Redone this. understand the point on maybe 100mm EPS, membrane then 100mm PIR. Is that going to give a significant difference? Or much better 2x 100mm PIR. I also haven’t taken the slab over the block work in this version as won’t have the EPS to shutter it. the willows - foundation detail (mh).pdf

So I’ve taken to drawing it up prior to chatting through with builder… thoughts? (Ignore some of my dodgy scaling eg courses not lining up)

Yup - we have some views ish but we also have a nicely landscaped garden that I've put blood sweat and tears into over the past 2 years to look down upon (yes we did do this first), plus the design of the roof overhanging the balcony also narrows the view to where we want it and not full vistas if you see what I mean?! It wouldn't be a turnkey approach no. I have an open book policy with my builder, I'm helping do a lot of the ordering and in return he's charging me just 5% on materials - which also helps cashflow as I save the 20% VAT. Then he's working on a day rate, rates pre agreed for trades. That's to get us up to wind and water tight then I'm taking over with subbies from there. We're 3.5 years in. Moving out of the bungalow in 2 weeks!

Sorry thought I'd said. 268m2. So we're quite similar. We're demolishing a bungalow nd replacing with 5 bed detached. 52A1 H.pdf 53A1 F.pdf

Haven't engaged a QS yet although we're in the midst of looking at self build mortgage and they are talking about requiring one. I have put it through Jewson Build Aviator as I have a self build account with them. They came back at £430k.

I’ve just put mine into estimators online for £192.50. I’ll let you know when I get it… (Surrey)

Yep I think it's where I'm getting to tbh. I think I have my head around where the thermal bridging issues will occur and will just solve them with the builder and suppliers. I've looked at different build methods but for various reasons we've stuck with masonry and are quite a way down the line. Thanks for those suggestions, I've been looking at 1&3 and will now look at 2!

Yeah I'm really pleased with them! Tharindudhan168 was the name. I paid £250 all in and have about 20 images. Really useful to help visualise things with the oh etc.

So I've now received structural calculations. I think I can decipher some of it but in a 90 page document I'm struggling with a lot of it! What is evident is although I've brought up thermal bridging there is nothing in here mitigating it. We have steel connections penetrating the wall for the balcony, steel posts going down to foundations etc. What next? I'm not sure who's responsibility it now is to take the structural calcs and turn them into something we can build from. Do I really need to pay for construction drawings form the architect etc.? Also whoever that is I now need to take on the journey with thermal bridging... HELP! (please!)

I built a garage last year and can’t wait for the roof to age and get a bit of moss on so that it’ll look older than it is!

Ok thanks. + 50mm less digging and take away!

So 50mm liquid screed plus extra insulation worked out cheaper than a sand and cement screed? That's interesting. It's where my head was going too tbh. The Architect, SAP and SE are going standard building regs with 150mm insulation and I'm trying to work out best way of increasing it i.e. do I reduce screed or just dig deeper. Sounds like a chemical screed works well for you. Plus cashflow is king so pushing the insulation back to after we have a superstructure helps!

We’re going with a traditional slab but I’m discussing the exact build up with my SE and wondered peoples opinions on best and most efficient… So assuming UFH would you go slab, insulation, screed or insulation and slab only with UFH in the slab etc? Is it better to have a thin chemical screed for faster heat up? We have predetermined FFL so I need to get the build up right to work out how far to dig down.

Understood. Given the mortgage co will charge per drawdown for a valuation I will obviously limit this as much as poss. It will boil down to cashflow though obvs. I was wondering if anyone had engaged a QS in their build and had any tips...

As in the QS price per certificate? I imagine they need to be involved for the whole project?

Unfortunately they have said they will want a QS throughout to confirm spending – they release their drawdowns on this basis - ‘when they require their next drawdown we will send out our valuer for a reinspection and request the QS Interim Report and QS Certificate of expenditure which will confirm the amount spent on works to date.’