What's best SIPS v Timber Frame - You won’t like what I’m going to tell you

Do I prefer sips panels over traditional timber frame for house extension and home build projects? And..... which is cheaper?
I have pulled out the main advantage points in that SIP manufacturers list, and I will examine them as follows:
Advantage 1….Build cost through economies of speed of construction, SIPs are faster, and therefore cheaper…. Because ……SIPs need less labour…60%, and
Advantage 2…. Simple logistics through a one stop off-site manufacturing process
….and Advantage 3…… Running costs and “Eco credentials” …. the lower annual energy costs SIPs are super airtight and have much better insulation properties.
Let’s use a real world example to see if the these claims live up to the hype.
I’ll compare u values and heat efficiency, speed to construct, and…of course,,,,, cost.

U values explained
How I designed this House Extension - start to finish, all the stages

[Fabiano]

Thoroughly enjoyable and informative, thank you Sir.

[chrismitchelmore]

Great content! Keep up the good work. Getting me prepped to build my outbuilding 🙏

[kevocos]

Great analysis and further makes the point that if you want to do anything construction related in the UK and have it turn out right, on time and on budget, then do it yourself!
Looks like you have an excellent integration of sketchup with the your excel costing sheet, would you do an upload explaining your workflow sometime?
I watch a lot of UK based construction related youtube and you content is top stuff and extremely useful !

[peterredwin]

Really good insight provided here with the Great I have had a few friends recommending Sips but the math never added up to me

[latebanana]

Great videos, thanks. However I would like to point out that your timber-framed wall example that reaches a u-value of 0.10w/m2K adds up to an overall wall thickness of 427mm, not 328mm as stated. A similar wall thickness to the SIPS example and no reason why it should be that different in thickness anyway.

[loki]

Really interesting comparison. I've been researching a lot of content around SIPs recently and very interested in their potential in the UK. I hadn't come across an analysis as focused as this. It seems harsh but the numbers don't lie. I do believe that SIPs will overtake traditional building in the near future once manufacturing processes have improved and costs come down

[ianhart]

Interesting video, full of useful information but you were talking about EPS SIPs not PIR so I'm not sure the thickness comparison for a given U-value, with timber frame infilled with PIR, stacks up. However PIR SIPS would be even more expensive than EPS ones so the cost comparison certainly does.

[GaborSzitas]

My company build almost everything with Sip, its a really nice system. We also do traditional timber frame but its a lot of more work.

[Jim_KYB]

Im looking yo build a 50sqm extrnsion for a house in London, so heavily researching SIPS. With labour costs being so high in London, SIPS is looking considerably cheaper than traditional methods (not timber frame however). The other factor is the general standard of builders in London is very poor in the domestic residential market. Having the extension facrory made is very appealing as if planned well glazing can be order once the SIPs design has been signed off.

[AceMcMoron]

This is more like a pre-fab vs. DIY battle. Due to the overhead cost/ logistics of pre-fab, it doesn't stand a chance for small footprints. However, thank you for providing us with the exact numbers!

[rupertmiller]

I worked most of my career as an analyst in the City. We took a lot of stick for being a bit shark like but at least when I was there, reputation was everything and you kept your word. I the last 4 years of my career I switched coverage to green tech. You almost wanted to count your fingers if you shook hands. No concept of shareholder value, they just expected shareholders to cough up more for no return! Some interesting ideas but no idea how to implement cost effectively . Fuel cell tech was the worst billions pumped in over 4 decades but we still do not have a commercially viable fuel cell. I suspect SIPs is much the same and heat pumps too. You take a simple and good idea and turn it over to the double glazing boys, who ramp up the price and blow the budget. Sips are a very basic concept, 2 sheets of 11mm OSB at £10 per sheet and a sheet of foam £58 ex vat, some glue and a press. Let’s say £90 in materials. So why are they so pricey? Lack of scale and lack of nous! Materials are cheap probably less than £90 presses are not. The number of presses limits production, hence big lead times and deposits required to finance holding the materials. How many presses would a manufacturer need depends on glue setting time but each press would probably cost between £30k and £50k more for computer control. It suddenly becomes a capital an, machine intensive operation which needs volume for economy of scale.

[lukeh]

Very interesting. I always found SIPs companies to come across a bit ‘salesy’.

I wonder if they become more cost effective with larger buildings, like a 3000sqft new build.

[skaraborgcraft]

Pricing up for an Aframe in Sweden, self build, , for some reason the local building planner is pushing for SIPS, which makes no sense, as my last roofing project was all stick with 380mm insulation/truss depth. Seems to be a breakdown in thought between architects and builders.

[philij]

Hi @build-better-things, I'm wondering how you batten out the exterior of the stud wall over the insulation and which side of the I insulation the breather membrane goes? Finally, the DPM, would you lap that up over the insulation or between that and the OSB and over or behind the breather membrane?
I was totally sold on SIPs but I've done the sums and it's madness how much cheaper timber framing is. (I'm looking at building an approx 6mx6m infill extension on a 1930s detached house). I've commented about suspended v solid floor as I'd like suspended but until now the solid seemed marginally cheaper, however now I've done the sums on the framing suspended flooring seems like a winner. Just need some hefty joists (or easi-joists) to span the 6m! Unless of course you would recommend at least one block support and divide the flooring up into sections?

[DoctorRetina]

Great vid.
How can i calculate u value of my wall, is there an online calculator or better yet a spreadsheet?
Thanks

[jmom]

What kind of foundation would you recommend for those wooden frame extensions. Does it have to be concrete base with brick border

[davidjack]

Ive just built a garden room using sips. For me the cost increase (not all that much) was worth it for the speed of construction which saves me money - because quite simply money is time!

[Mr-T]

Great comparison, but there seems so much bias in it.
Cost comparison alone it would have been great to have 2-3 quotes for the timber frame build. Seeing the sips build cost was based on a fully built structure. I imagine timber is more expensive with labour factored in from a non DIYers persepctive.
Also the likes of kingspan tek-13 achieves a 0.13 u value for a wall thickness of 370mm as a reference.

[stevemcc]

Since I was in the carpenters union, and I have built several kinds of construction, I personally stick with SIP. Our company put up seven metal SIP schools in Florida versus another company who put a eight conventional. WE were done 7 months ahead of the others guys. Wood SIPs are slightly more difficult because of weight. However, Planning is always the secret on every job, but SIPs are too easy.

[ghosthandle]

Your thickness calculation is wrong for the timber frame. Its actually 427mm thick.