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So all of the ICF quotes are in. I've tried to standardise them as much as possible, but some have interesting notes which I'll detail below. Putting this up for others who might find it useful in deciding their supplier or working out costs, but also for any feedback or thoughts from the more experienced (that's all of you!).

 

Our build is approx 220sqm footprint and 260sqm of wall.

 

Durisol includes a 22% discount that they put on without negotiation 

Beco Walform have quoted for the 375 but say the 313 would save around £8K (inc vat) and only increase the U value to 0.165 (though the published value is 0.18) so much better value

Nudura say that a U value of 0.24 is plenty and anything more gets really expensive

Velox includes the steel that goes inside the wall.

 

I've included a price of concrete at £100+vat/cbm. This is a little on the high side, but it gives comparison.

 

None of the quotes include rebar (if required [except Velox]) - would have to wait for SE calcs. Can anyone suggest an amount (in £ or quantity) that they used on their build?

 

I know that we'll be able to reclaim the VAT on a new build but were costing things as a worst case scenario.

 

Labor to construct I'm guessing at 9 days for 1+1+me: 2 days build,  1 day pour (lower ground). 3 days build 1 day pour (upper ground). 1 day build, 1 day pour (gables, finishing off etc).

 

 

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Hope that helps someone and thanks for your thoughts!

Edited by ZacP
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Excellent thread for people considering icf. I didnt realise there was so big a difference in concrete quantity between different suppliers. 

 

Personally I am a big fan of nudara (only other icf I would have seriously considered was amvic) but I did feel nudara played the card that the extra u value was not worth it to make them more cost competitive in comparison to other suppliers as they where shipping the icf from the west coast of Canada which gave them a big disadvantage.

 

We bite the bullet and added the extra insulation to nudara, I am happy with result. Will do homework on build 2 but hopefully be either nudara or amvic with 200mm extra EWI on the block (as @stones build in orkney).

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2 minutes ago, Alexphd1 said:

Excellent thread for people considering icf. I didnt realise there was so big a difference in concrete quantity between different suppliers. 

 

Personally I am a big fan of nudara (only other icf I would have seriously considered was amvic) but I did feel nudara played the card that the extra u value was not worth it to make them more cost competitive in comparison to other suppliers as they where shipping the icf from the west coast of Canada which gave them a big disadvantage.

 

We bite the bullet and added the extra insulation to nudara, I am happy with result. Will do homework on build 2 but hopefully be either nudara or amvic with 200mm extra EWI on the block (as @stones build in orkney).

 

I didn't think about concrete either until I asked and realised there was quite a bit of variation. Guess it shows that the ICF with plastic/metal ties need more and the ones with internal and external panel connected by eps/woodcrete need less.

 

Hadn't considered that was the reason fo the hesitation of providing a quote from Nudura for a lower u-Value. I guess a block that's almost twice as thick will need twice the shipping cost! 

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Have you priced AMVIC? They came out cheapest - about 50% cheaper than NUDURA for reference once you factored in all the "extras".

 

FYI we're in th emiddle of our basement assembly: Looking like 2 weeks from delivery of forms to concrete pour. Once you factor in the setting out of tracks etc (1 day alone), a full week for assembling blocks and doing rebar, and other 2-3 days bracing and setting up props and checks before the pour. That assumes you've no complicated or large openings.

 

Builder started forms on our simple 100m2 basement on Monday, will be finished tomorrow lunch time, bracing the four openings in the afternoon and into next week assuming props arrive on Monday, with pour hopefully on Wednesday. Extra insulation will go on with the tanking the week after.

08.jpg

Edited by Conor

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@Conor I had forgotten to add setting out in there. To be honest we're probably leaning more toward the woodcrete products (though not completely set yet) because of reduced need to brace and add extra rebar (except lintels etc.) so I wasn't really thinking about the extra time for those bits. I guess that could increase or labour cost (slightly) for the systems that need those things added in?

 

And yes, I completely forgot about AMVIC! **scuttles off to find an email contact to send plans to**

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@ZacP what's your procurement strategy? Are you going to buy the Icf and assemble yourself along with some assistance? Bear in mind structural warranty erc. That was my plan but in the end I went with a contractor to supply and fit... Came in at £51k, a fair bit more than my DIY estimate of £40k... But  I'm saving £3k on not needing a warranty and it'll be done 10x faster lol. And contractor takes all the risk. I recommend you price up a contractor to supply and fit the ICF along with all structural elements.

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@Conor Buy ICF ourselves and have builder construct with me labouring/getting in the way. Then the builder will continue with floor/ceiling etc and separate carpenters to cut roof onsite. Windows fitted... not got that far yet, but we know we definitely do want to have windows, and they will need to be installed by someone! We'll then probably be doing the external stone slips ourselves, bit by bit, evenings and weekends after everything is weather tight.

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I'm also doing a great job of getting in my builders way 😅

Edited by Conor

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Small point, if you order the blocks and are on site with the builder every day, there might well be less wastage.

With more traditional builds, wastage isn't too big a problem, but you can't just pop down the BM to get a few more ICF blocks. 

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23 minutes ago, ToughButterCup said:

Small point, if you order the blocks and are on site with the builder every day, there might well be less wastage.

With more traditional builds, wastage isn't too big a problem, but you can't just pop down the BM to get a few more ICF blocks. 

@ToughButterCup I've read your Durisol blog. Plenty to watch out for - thank you for detailing your experiences! Our builder seems to have a great local reputation with clients and other trades, and has done 2 Durisol projects before. Only hang up is he has never done a whole house. Just large extensions etc. I don't see that much of a difference, just a bit bigger! Famous last words. Also seems happy to learn about other ICF systems so we'll see.

Edited by ZacP
SPG

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Good to get some prices, you might want to include hire of a concrete pump truck, another Icf company worth a check is JUB. There blocks come with external wall insulation included in the block, so no need to fit after, that's what I am planning to use next year. 

 Check out  @Simon R. 

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@ZacP You asked about steel price for rebar. My SE spec'd 2x 16mm bars over each opening to form the lintels. Total was less then £200 for 15 openings, so pretty inconsequential.

 

A bigger cost will be ply, timber, fixings and sundries for bracing, especially if using a poly system

 

You could also check out Logix which is manufactured on the south coast. Discount available if purchased together with Isoquik raft.

 

If I was doing my build again I would definitely spend more time considering adding additional external insulation as @Alexphd1 has suggested. 

I went for 200mm outside EPS blocks and it was much harder cutting, bracing fixing them than a standard ~70mm block. However the chance of blowouts or bulges is pretty much zero on the 200mm skin.

 

Getting a really good U value is easy with ICF so anything over 0.2 seems a bit of a shame/waste to me.

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Thanks @willbish. What ICF did you use? I'm guessing that those like Jackon/Beco etc. that need rebar though the whole structure will cost more.

 

Agreed on the u value, was a bit disappointed to think that Nudura might not have wanted to quote  for a larger block size because of the transport costs. I could be wrong on that though.

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I used Logix, think the block is called XRV6-8, the thickest block they do.

 

As I understand for Nudura if you want to increase the U value they use a standard block with a larger concrete void, you then push EPS inserts in which reduces the concrete to a normal ~6 inch.

Advantage of that is the plastic webs are close to outer face so good for fixings. Disadvantage is it's extra work pushing the inserts in. One self builder I visited mentioned it was a right pain and slowing him down a lot. 

 

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The nudara inserts are a PITA. Think they do a wider external eps block but think it's just a standard block with eps bonded on in the factory bit of a half ass atempt. That's why I like the idea of adding eps on site after the concrete has been poured. I thought the quadlock icf was a cracking system for thick eps but after a lot of research on American build chats, the general opinon was nudara and amvic where the best.

 

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We're just sticking on 40mm of PIR on the insides of the walls (then plasterboard screwed through to the webs) to get the standard Amvic blocks down to 0.15. considerably cheaper than a larger block.

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@Conor interested to know why you put the PIR on the inside? Are you concerned with the thermal mass of the concrete bring outside the main thermal envelope? 

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14 minutes ago, ZacP said:

@Conor interested to know why you put the PIR on the inside? Are you concerned with the thermal mass of the concrete bring outside the main thermal envelope? 

 

Doesn't really work like that - there's a very long thread with lots of formulae and arguments about this subject. The wall should be considered as a single thermal element, where the concrete is in the profile, doesn't really matter.

 

It's an order of magnitude cheaper to put a 40mm sheet of PIR on the inside vs a 100mm sheet of EWI grade EPS on the outside.

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How many pours are you going to do ? Just because a suppler states a max height per pour doesn't mean you will feel comfortable with such a height. I know I did alot more pours than originally planned. I would never have poured the internal Durisol blocks anywhere near the same as the externals. 

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Have you looked at polar wall? They are a UK based company and seem helpful. I like the fact that you can change the insulation values easily and It looks more adaptable than the standard blocks. They also use XPS rather than EPS which I think is stronger/better u values per mm. I also am waiting on a quote from Nudura, I like the fact that Nudura have a good track record and there are a lot of users on this forum.

 

Polar wall quote was £56.30/m2 for the block that's a 80mm/80mm XPS foam with 0.19 u value

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@ZacP have you had a structural engineer look at yours yet? From the brief look I had at your drawings I thought you had two walls that will be retaining the ground and forming the structure for the next floor to go on. 

If this is the case I would expect a lot of re- bar, and even an increase in block size to accommodate a larger concrete core for the strength. 

 

 

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@ZacP just curious if you have managed to get cost comparison from AMVIC in the end?

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@Russell griffiths just parted company with old SE. Was the worlds worst at getting back to me and I haven’t got time for people I’m giving a large wedge of £ to who don’t reply to calls, emails or texts for 2 weeks. New SE needed!

 

@NickK sent them plans and they said they’d get a quote to me this week. Nothing yet. Think we’re probably looking at a woodcrete option anyway, but that might change if it’s a significant difference!

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On 17/09/2020 at 13:03, Alexphd1 said:

Excellent thread for people considering icf. I didnt realise there was so big a difference in concrete quantity between different suppliers. 

 

Personally I am a big fan of nudara (only other icf I would have seriously considered was amvic) but I did feel nudara played the card that the extra u value was not worth it to make them more cost competitive in comparison to other suppliers as they where shipping the icf from the west coast of Canada which gave them a big disadvantage.

 

We bite the bullet and added the extra insulation to nudara, I am happy with result. Will do homework on build 2 but hopefully be either nudara or amvic with 200mm extra EWI on the block (as @stones build in orkney).

Hi we are consIdering using ICF, how did you find the Nudura system? I have been told to stay away from poly systems?
Do they overheat?

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On 18/09/2020 at 13:04, Conor said:

 

Doesn't really work like that - there's a very long thread with lots of formulae and arguments about this subject. The wall should be considered as a single thermal element, where the concrete is in the profile, doesn't really matter.

 

It's an order of magnitude cheaper to put a 40mm sheet of PIR on the inside vs a 100mm sheet of EWI grade EPS on the outside.

I was doing some research and been advised that in order to use the thermal mass properties of concrete you can’t really have any insulation 

material internally, ideally you need solid concrete face to get the best performance. If this was correct insulation applied internally would not help.

would be interested to learn more, if there are other opinions out there.

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