ToughButterCup Posted February 10, 2021 Share Posted February 10, 2021 A few people have been talking about their build costs recently. ( @ProDave , @nod, among others) All of them use the cost per square meter measure. When I used the same measure in a comment on an unrelated thread, I got a one word answer as to why the measure was poor . ' ...Geometry... ' That one word answer sparked my interest (as do many of the author's posts). I poked around in the list of RICS measurement methods, and bumped into this document about valuing individual new homes. I'm aware of the conflict between value and cost. But the point made in the introduction to that document talks about the need for consistency of measure : what the teaching profession might call working towards formal units of value, rather than informal ones.. Geometery has to play a role in deriving build costs. But so do many other factors. And geometery can be complex : square meterage , simple. Is cost per square meter despite its simplicity the only practicable cost measure? Or are there others we should consider? Link to comment Share on other sites More sharing options...
markc Posted February 10, 2021 Share Posted February 10, 2021 Cost per square meter is a pretty good baseline figure. Building geometry does affect the cost but this can be factored in. We used to price steel building erection on a per tonne price plus a `buggeration` factor for restricted sites, difficult access, component complexity etc. plus any welding and on site fabrication etc. As we did some very complex jobs the base £/Tonne figure rarely worked out but did give a good start point. Link to comment Share on other sites More sharing options...
Ferdinand Posted February 10, 2021 Share Posted February 10, 2021 How big is my bank account? ? Link to comment Share on other sites More sharing options...
Gone West Posted February 10, 2021 Share Posted February 10, 2021 1 hour ago, ToughButterCup said: square meterage , simple. Are you talking about external, gross internal or net internal square metreage. Link to comment Share on other sites More sharing options...
nod Posted February 10, 2021 Share Posted February 10, 2021 The main thing that dictates cost is availability of laboure The hourly rates or price m2 paid on sites Count for very when it comes to self builders Trades or builders pricing for self builders Seem to just pluck a number out of the sky Depending on how busy they are Two friends of ours have just finished there third self build He’s a quantity surveyor with over 40 years experience dealing with very large building projects He openly admits he was miles out with the Labour Two quotes from reputable builders came in at 420k A third over 500 k When the third was told he wouldn’t be getting the job He said ok I’ll match the other two I would say for the things that you can’t manage yourself Don’t underestimate the cost of the labour Costing the material are quite straightforward can can be done online Link to comment Share on other sites More sharing options...
ToughButterCup Posted February 10, 2021 Author Share Posted February 10, 2021 1 hour ago, PeterStarck said: Are you talking about ... Exactly Peter. The term is opaque. It seems to me that the vast majority of self builders and every single architect I have spoken to , all cite a simple(istic ?) measure : square meterage. And @SteamyTea has a point when he says it is a poor measure. But at least its consistent in its inaccuracy. I think the argument he might advance is that cost per square meter is a cloak under which a good deal can be hidden. Rough but ready? Link to comment Share on other sites More sharing options...
SteamyTea Posted February 10, 2021 Share Posted February 10, 2021 (edited) Is an unexpected problem of setting a price based on area is that it justifies corner cutting by the contractor? I typed this before I read the previous post. Edited February 10, 2021 by SteamyTea Link to comment Share on other sites More sharing options...
Gone West Posted February 10, 2021 Share Posted February 10, 2021 1 minute ago, ToughButterCup said: But at least its consistent in its inaccuracy. Large difference in results between external and net internal measurements, and with PH type structures with possibly more complicated and costly external walls and the open plan design currently in vogue I still think the level of inaccuracy is so great that the parameters should be clearly defined. Link to comment Share on other sites More sharing options...
ToughButterCup Posted February 10, 2021 Author Share Posted February 10, 2021 4 minutes ago, PeterStarck said: ... I still think the level of inaccuracy is so great that the parameters should be clearly defined. So why don't we? Ease ? Brevity? Link to comment Share on other sites More sharing options...
SteamyTea Posted February 10, 2021 Share Posted February 10, 2021 I think for a self builder, pricing needs to be the sum of the individual components. It is not the same as a volume builder where they have different cost centres, multiple sites competing for resources, different finance models, a better working relationship with suppliers etc. If a self builder aims to build at say £1500/m², and end up spending £1200, or £1800, it makes no difference, the house is built, they don't know the what they spent till the job is done. And a self built house is never really finished anyway. Link to comment Share on other sites More sharing options...
Gone West Posted February 10, 2021 Share Posted February 10, 2021 1 minute ago, ToughButterCup said: So why don't we? Ease ? Brevity? I would guess that 'professionals' probably all use the same method so don't think they have to define it. The problem is that, if for example, they use net internal area it doesn't take into account the differences with say PH wall construction but they just continue in the same old way, so it's probably laziness. Link to comment Share on other sites More sharing options...
ToughButterCup Posted February 10, 2021 Author Share Posted February 10, 2021 25 minutes ago, PeterStarck said: ... so it's probably laziness. And I thought I was being unkind when I had the same thought. Link to comment Share on other sites More sharing options...
Dave Jones Posted February 10, 2021 Share Posted February 10, 2021 1 hour ago, nod said: The main thing that dictates cost is availability of laboure The hourly rates or price m2 paid on sites Count for very when it comes to self builders Trades or builders pricing for self builders Seem to just pluck a number out of the sky Depending on how busy they are Two friends of ours have just finished there third self build He’s a quantity surveyor with over 40 years experience dealing with very large building projects He openly admits he was miles out with the Labour Two quotes from reputable builders came in at 420k A third over 500 k When the third was told he wouldn’t be getting the job He said ok I’ll match the other two I would say for the things that you can’t manage yourself Don’t underestimate the cost of the labour Costing the material are quite straightforward can can be done online no need to be. Have a QS produce a quote from the plans, it will be down to the last screw. They will use industry standard times for laying 1m2 of bricks, stud, tile etc etc banks use them to lend on so they are accurate enough. Link to comment Share on other sites More sharing options...
nod Posted February 10, 2021 Share Posted February 10, 2021 11 minutes ago, Dave Jones said: no need to be. Have a QS produce a quote from the plans, it will be down to the last screw. They will use industry standard times for laying 1m2 of bricks, stud, tile etc etc banks use them to lend on so they are accurate enough. Spons ? 1 Link to comment Share on other sites More sharing options...
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