Embodied Carbon

[Big Neil]

Has anyone whether on a build they have completed or as an exercise for one in the future, taken a record of the embodied carbon involved in all material and transport for their project. Never mind about carbon cost to run, i mean (fingers crossed hoping i've used the word embodied in the correct context) to produce the materials used to build the place and transport all that to site. Maybe even to include an allowance for the labour element, so their vans/trucks etc.

[Jeremy Harris]

I had a go at trying to work it out, for the various different options we were looking at, but in the end found that keeping track of it, and working out the offset over the life of the house, just got to be too much work.

 

The house build itself has  a pretty low embodied CO₂ level, mainly the concrete slab, but that's only 100mm thick, the steel reinforcement in it and the EPS insulation underneath it.  There are no fired bricks or cast concrete blocks in the house itself,.  The frame is built from sustainably certified timber, the cladding is locally grown (6 miles away) and locally milled (3 miles away) larch, the wall and roof insulation is recycled newspaper and the roofing is recycled plastic slates.  The internal flooring is a mix of bamboo (which is grown from sustainably managed plantations) and travertine stone, but both came from miles away (Taiwan and Turkey respectively), so had a fairly high transport C0₂ contribution.

 

We do manage to offset this to some extent, as overall the house "produces" -0.9 tonnes of CO₂, which means that it will end up "repaying" its build CO₂  debt within a few years (I might sit down and try to estimate how long that will take).  In simple terms, our house is roughly the same as having over 40 mature trees on our plot, in terms of its CO₂  impact, except we couldn't have fitted 40 matures trees on it even before we built the house.

 

The hardest part to work out I found was the transport CO₂  impact.  It's really hard to find out exactly how goods were transported from far away, especially when there are multiple journeys involved.  For example, the timber in our frame was grown in Sweden, probably milled there, then transported to Ireland, where it was made into the frame of our house, then the frame was transported by truck and ferry to our plot.  That's a lot of travelling for what is component that was grown in a sustainable woodland.  I've no idea how much CO₂  went in to turning harvested bamboo into flooring, not do I know for sure how it got here, but can guess that it would have meant a truck ride to a port, a 4 to 6 week sea journey in a container, then a couple of other truck trips within the UK before it got to us.

[ProDave]

I would imagine plasterboard is another big contributor.  Then all the "things" like mvhr, ASHP etc then the kitchen units and appliances.

 

You are getting int cfsh level 6 territory.  A Cousin used to work as a builder and he did one cfsh level 6 house, he said it was a paperwork nightmare, every journey including to and from work had to be logged, even how many times they went to the toilet.......