Timber frame vs ICF vs Traditional masonry for a new build

[Indy]

I have another thread in the new build design section detailing the journey to get the plans finalised and submitted. In the meantime, have been reading up about how to actually build and also attended the NSBRC show over the weekend and took in their talks/seminars (quite useful for a beginner). 

 

So far, I have no preference for a particular method of building apart from wanting what everyone wants - super speed and super cheap, with a top quality finish(!)

 

I've listed out the pros and cons of each to try and understand the differences between the three methods:

 

Traditional masonry - Pros
1. Cheap parts and easy to get insurance/mortgages
2. Easy to DIY in the future 

Traditional masonry - Cons
1. Slow to build
2. Labour in London is expensive (£500 for a brickie apparently) so cheap parts are offset by the long time it takes to build and get water/airtight.

 

Timber frame - Pros
1. Quick to build when on site as all the design is done prior and built in a factory
2. Can find companies to do foundation slab and erect structure - which is the hardest part of the build.
3. Great insulation and thermal efficiency

Timer frame - Cons
1. Used to be about 10-15% more expensive pre-COVID, and this has only got worse with timber prices shooting through the roof. 
2. Slightly harder to get insurance/mortgages but this is the dominant method of new builds now apparently.
3. Noise issues are greater in a timber framed house?

 

ICF - Pros
1. DIY element of laying out blocks, meaning some labour costs can be saved. 
2. Monolithic structure means efficient house, and a feeling of being much more solid as compared to Timber frame. 
3. Less noise issues - especially if paired with a block and beam floor.
4. Used to be relatively expensive - but now very competitive as concrete costs haven't gone up as much as timber in the last 2 years!

ICF Cons 
1. DIY options will become limited in the future as cutting through concrete isn't fun
2. Waterproofing external insulation is key - though not impossible.
3. As with TF - harder to get insurance/mortgages as this is less popular but now growing.

 

All in all, I'm leaning towards ICF now as having a concrete structure and combination of beam and block floors will get rid of my biggest bugbear - the noise issues in old housing stock. Hate hate hate creaky floorboards and sound travelling through the house when you drop something relatively light. 

 

Thoughts greatly appreciated. Cost is obviously a concern though all conversations point to each system roughly equating to about the same in the end - higher part costs are offset with quicker build times (and lower labour costs). 

[SuperPav]

We're in the middle of building with thin joint masonry (so as quick and airtight as masonry can be), facing stone outer. While it *can* be neater, quicker, etc. it still relies on messy trades, and frankly their attention to detail is just not good enough for a high performance house, so unless you're there all day everyday on the details or doing it yourself, I think you'll be disappointed.

 

I would 100% not do it again, and would go for timber frame all day long, whether clad, rendered or even with stone/brick outer. I would probably get a package company for a foundations + frame/shell build such as MBC. We got them to quote and looked into it in detail, but (unfortunately) stuck with masonry.

 

I have no views on ICF as have no experience of it, but suspect the insurance/mortgageability is still trickier than timber frame.

[shuff27]

As someone who has recently paid for concrete foundations I would dispute that cost of concrete hasn't gone up much lately. I found the percentage increase greater than that of my timber frame. 

[IanR]

14 minutes ago, Indy said:

Timer frame - Cons
1. Used to be about 10-15% more expensive pre-COVID, and this has only got worse with timber prices shooting through the roof. 

 

I'm not sure you can pluck figures out of the sky for pricing. I didn't get just TF prices within 15% of each other, from different suppliers for identical performance, so I'm not sure how it could be said that TF is/was 10-15% more expensive than masonry. In fact I had a 40% spread on just my TF quotes (Beattie Passive were a significant outlier).

 

And, is the difference in cost the same for all performance levels. Is it really more expensive to achieve PassivHaus targets, for instance, in timber than it is in masonry. And does the cost difference include the efficiencies that can be made on the foundation/slab, for having a light weight structure, or does it just assume standard strip foundations for each?

[Indy]

19 minutes ago, SuperPav said:

We're in the middle of building with thin joint masonry (so as quick and airtight as masonry can be), facing stone outer. While it *can* be neater, quicker, etc. it still relies on messy trades, and frankly their attention to detail is just not good enough for a high performance house, so unless you're there all day everyday on the details or doing it yourself, I think you'll be disappointed.

 

I would 100% not do it again, and would go for timber frame all day long, whether clad, rendered or even with stone/brick outer. I would probably get a package company for a foundations + frame/shell build such as MBC. We got them to quote and looked into it in detail, but (unfortunately) stuck with masonry.

 

I have no views on ICF as have no experience of it, but suspect the insurance/mortgageability is still trickier than timber frame.

 

I attended a walk through tour as the first thing when I reached the NSBRC which was led by an experienced builder of many years. His view was pretty much the same, the traditional method isnt suitable for modern, thermally efficient homes and he wouldn't recommend it anymore given that newer tech existed.

 

MBC as a company has been recommended and I spoke to them briefly while there. Seemed quite helpful and are willing to take a look at our custom design to see what they can do. Obviously haven't explored in any detail on how this would come out costwise though the guy did hint that the cost conversations were much easier to have in 2018 as compared to now!

[tonyshouse]

Think longevity, long term comfort = thermally stable, solid feel, good sound insulation 

[Indy]

4 minutes ago, IanR said:

 

I'm not sure you can pluck figures out of the sky for pricing. I didn't get just TF prices within 15% of each other, from different suppliers for identical performance, so I'm not sure how it could be said that TF is/was 10-15% more expensive than masonry. In fact I had a 40% spread on just my TF quotes (Beattie Passive were a significant outlier).

 

And, is the difference in cost the same for all performance levels. Is it really more expensive to achieve PassivHaus targets, for instance, in timber than it is in masonry. And does the cost difference include the efficiencies that can be made on the foundation/slab, for having a light weight structure, or does it just assume standard strip foundations for each?

 

Ok, so the figure was taken from a comment that one of the architects at the show threw out, and is a very generalised number. I totally agree that you can't compare until you specify in detail the level of efficiency etc that you want, and I don't really have the answers to most of the questions you've posted here. 

 

I guess what I'm trying to understand is broad brush strokes - if the costs are the same (ish) for a similar level of passive haus-ness, would one system win over another?

Edited January 31, 2022 by Indy

[Indy]

3 minutes ago, tonyshouse said:

Think longevity, long term comfort = thermally stable, solid feel, good sound insulation 

 

Yeah, Fabric first is the term that was thrown at us several times. This will mean upping the spec on the fundamentals and maybe cheaping out on 2nd fix items like doors/kitchens/bathrooms for now, as the latter will be relatively easier to upgrade in the future. 

[SuperPav]

Don't get me wrong, I'm not saying there aren't any reasons or upsides to masonry construction (we had the same debate before committing), all I'm saying is that having gone through the reality of a build with masonry, I would not repeat or recommend it for most high performance houses due to the realities of trades using this type of construction.

 

If you've got a builder who is shit hot on details, thermal bridges and the like, and who can guarantee that all of his subbies and labourers will operate at the same level, OR you/a project manager micromanages the detailing full-time on site, you will NOT get real-world performance from a masonry house that you think you'll get in theory.

 

I appreciate that is a bit cynical and I'm sure people will have examples of good experiences of masonry build, but I've yet to come across mainstream trades who will go around and fix every tiny little nick in a membrane, or take care not to make a hole or leave a small gap, or think about how they need to change the construction to avoid vapour build up or thermal bridging on a particularly detailed part of a house. Even if you give them detailed architect's drawings, they will follow them 90%, not 100%.

 

As always, that is just my *opinion* based on our experience. As Tony suggests, there are plenty of upsides to masonry construction, and the balance of which is more important or carries more risk is down to you and your house, not to a bunch of grumpy selfbuilders on a forum

[nod]

If your looking at cost 

Solid

Icf 

TF

[Indy]

3 minutes ago, nod said:

If your looking at cost 

Solid

Icf 

TF

 

I assume you're quoting this as a package of labour and materials cost, rather than just materials?

[Indy]

27 minutes ago, tonyshouse said:

Think longevity, long term comfort = thermally stable, solid feel, good sound insulation 

 

Yep, this is very much the intent. Plan is to have insulation far in excess of building regs, but not sure if we want to go all the way to Passiv Haus standards. ASHP, Wet UFH, MVHR. One thing I'm not sold on yet is Solar PV. The plan is allow for this in the future, but trying to understand whether it makes sense to go all in now and take advantage of the VAT rebate or leave space in the plant room, beef up the roof trusses and add in the future. 

[Bitpipe]

52 minutes ago, Indy said:

So far, I have no preference for a particular method of building apart from wanting what everyone wants - super speed and super cheap, with a top quality finish(!)

 

You can have two at the cost of the third, take your pick

 

We did TF, looked seriously at ICF (contractor, not DIY) and what swung it for us as novices was the amount of progress we would get on the build using a single TF contractor plus the high quality of passive detail (insulation & airtightness) built in that package.

 

We did not use MBC's foundation system as we had a basement but that would have been another decider as they take responsibility for that as well as the frame - which is peace of mind both from a practical point of view (A fits onto B) but also the passive detailing.

 

As the frames were factory built, we were able to have the windows pre-ordered and arriving on site within a week of the frame being complete externally.

 

Once they were installed and taped to the internal airtight layer we were able to get the exterior cladding on and the roof (which was felted and battened by MBC) and roof lights completed all within about 6 weeks of commencement.

 

MBC then return to pump the insulation and do the airtightness test.

 

When the frame was complete we had all internal stud walls, floor decks and temp stairs which meant we could crack on with first fix within weeks. 

 

We also experienced a big difference between TF vendors, mostly to do with the degree of interior stuff walling, insulation and sundries like cranage, welfare, safety systems etc.

 

So TF wins for speed and quality (assuming you have a quality crew) but the cost is higher. However you need to offset that against how long you want to wait to start 1st fix and eventually move in.

[nod]

47 minutes ago, Indy said:

 

I assume you're quoting this as a package of labour and materials cost, rather than just materials?

Yes

[Simplysimon]

timber now coming down in price, concrete and associated products rising steeply due to energy price increases

[tonyshouse]

It is really very cheap to add insulation during construction, retrofitted is incredibly expensive, so much so that it doesn’t happen, just look at the housing stock 

 

I once wrote an article about the cost benefits of retrofitted loft insulation, diy, paid for itself in half a winter with not much there, 18 months when 80 or 100mm there already. 
 

look at the rates for EWI which almost every house needs, even new ones!

[Iceverge]

Masonry build here. It becomes micromanaging torture or a lot of self labour to get things the way you want them if aiming for passive standards. 

 

Probably a package MBC style if I was to do it again and save a lot of heartache and wanted to save my time for other elements of the build. 

 

I like the woodcrete ICF systems too if my heart was dead set on concrete. 

 

If I could convince a team of picky joiners to stick frame a house that would be the dream......

[joe90]

21 minutes ago, Iceverge said:

Masonry build here. It becomes micromanaging torture or a lot of self labour to get things the way you want them if aiming for passive standards. 

Mine was also masonry but was lucky to have a brilliant team and I was on site to project manage, I didn’t have to micromanage as they took my instructions seriously.

[Happy Valley]

We are building in ICF - polystyrene blocks. We have a builder.

 

This is our first new build and the builder whilst excellent and experienced with 30 years has never built with ICF before so a big learning curve. Builder is very conscientious and quality of work is superb. The speed of construction is a big advantage. There is very little we would change - but one thing that would have made the whole build easier is designing the openings of the house (windows doors sliders) around the size of the blocks. There is a window which is right on a corner which is not ideal when cutting ICF corners. We would also get a structural engineer who understood ICF as ours has lots of rebar which the manufacturer deems unnecessary.

 

The blocks sit on a waterproof concrete raft with a water bar. The ICF is faced in natural stone and blockwork (to be rendered). 

 

We have not moved in yet so can't comment on how it works in reality. 

Edited January 31, 2022 by Happy Valley

[JohnMo]

Not sure why timber frame would be an insurance issue, nearly all new housing in Scotland for the past few decades has been timber frame.

 

Why block and beam, insulated concrete slabs don't creak either.

 

22 minutes ago, Iceverge said:

I like the woodcrete ICF systems too if my heart was dead set on concrete. 

 

That's what I chose, did it myself, no regrets. Dead pallets saved from landfill, up cycling at its best. Four weeks start to finish ready for roof.  Stone or brick slips attach direct to woodcrete, no block work required.  Direct internal plastering equals airtight walls, or cement, lime parge coat.

[JohnMo]

2 minutes ago, Happy Valley said:

I would also get a structural engineer who understood ICF as ours has lots of rebar which the manufacturer deems unnecessary

Would agree with that, our structural steel requirements were huge, challenged the engineer and it was reduced by about 70%, but still had considerably more than the manufacturer said that would be needed

[Iceverge]

@JohnMo

 

I guess the woodcrete ICF doesn't have a continuous concrete core for airtightness like a polystyrene  so depends on the internal render?

 

Can it be plastered with sand and cement externally? 

 

 

 

[JohnMo]

26 minutes ago, Iceverge said:

@JohnMo

 

I guess the woodcrete ICF doesn't have a continuous concrete core for airtightness like a polystyrene  so depends on the internal render?

 

Can it be plastered with sand and cement externally? 

 

 

 

No more like a concrete matrix. You can do a render direct to the outside.  We did an internal parge coat (sand cement and lime) then battened and plasterboard with taped joints.

 

Outside is mix of stone slips and vertical larch cladding.

[Indy]

15 hours ago, Simplysimon said:

timber now coming down in price, concrete and associated products rising steeply due to energy price increases

 

Its always the opposite of what you end up planning for isn't it. Sods law that we'd choose a construction method on price (as a factor) and then end up having to pay over the top once we're locked in!

[Indy]

12 hours ago, Iceverge said:

@JohnMo

 

I guess the woodcrete ICF doesn't have a continuous concrete core for airtightness like a polystyrene  so depends on the internal render?

 

Can it be plastered with sand and cement externally? 

 

 

 

 

I havent yet researched the different ICF systems so not too sure about the woodcrete vs continuous concrete core - thanks for the pointer, something to add to the reading list.