Carbon neutral homes for mere mortals
You cover a lot of interesting, and valid points, and it is hard to disagree with most, if not all.
But the devil can be in the details, so in the spirit of debate may I raise a few points for consideration.
First up, and it's a doozy, is to try and get towards an acceptable definition of 'carbon neutrality'. To my eyes and ears it is ever so slightly loose and, depending on who decides to embrace it, the poor old public/consumer could be forgiven in thinking it is all manner of things that it may not actually be.
Personally, I have been trying to advocate the notion of enviROI, which is different to the financial version because the amount of money is nowhere near as relevant (though a factor - money poured into black holes may more usefully be redirected to green ones) as the impact on our planet, and hence kids' futures. So you may never get a return on an eco-investment, but it is still worth doing if reducing CO2 is your bag. The corollary of this is that you may make all sorts of noise on the green hue of it all, but actually the initiative may work out worse once every factor has been taken into account. This does have a bearing on construction issues as mentioned later.
In defence of aged rockers, so long as Metallica insulate their homes with their beards, and otherwise do as they say, I see nothing odd at all. What I do find less than compelling, however, is Squander Spice standing up with her newborn to plug her next concert whilst saying her presence was 'for her daughter's future', and then barely a week goes by before it turns out the group is getting a Lear jet each in case they have a hissy fit with each other. One reason why some felt the messengers rather undercut the message in this case. So which topic actually did get out there? I'd hazard it's more 'anyone else but me', which is hardly a motivational kickstart to the masses.
And while the last few days the media wires have been humming with such vastly critical topics as plastic bags and water bottles, I am glad to see that here we do have some thoughts on what is a more major issue, namely personal home energy consumption.
Back to the CN definition, even without heating I'd say that, without offsetting (a whole other, and equally mine-strewn topic), the CNzeroHome is still going to err on the negative simply because quite a lot would be involved in making it. See, new stuff does have a carbon consequence, the minute you dig its building blocks from the soil.
And while I am very happy to consider solar, heat-pumps, wind turbines, etc, beyond ROI I still have to be convinced with some on the enviROI.
Insulation is a bit of a no-brainer, so I can't quite figure out why vast amounts of effort is not being made to maximise this aspect's benefits RIGHT NOW. How many homes, for instance, could be insulated with the £5M blown on the latest carbon footprint ad campaign?
And as one who lives in a dwelling where carbon footprints are what you walk from the fireplace to the outside loo, I get nervous when the ODPM new-builds on flood plains look like getting a tip-top rating in the HIPS stakes, but without a cavity wall to fill in my very much already existing structure, I worry about being unfairly discriminated against by some rampant, half-cock, ill-considered box-ticking process over product.
But if we are to have new-builds, then yes, for heaven's sake let them be as you describe.
UK builders will of course take note, and will charge accordingly, no doubt.
1 comment:
Peter,
'Carbon neutrality' is almost as slippery as 'green'! One of the key things is the timescale. If you emit CO2 now, then should we call it neutral if it is mopped up sometime in the distant future? Tree-planting schemes fall into this category. If I owed you 100 quid, you may take a dim view of me setting up a 1 pound a year standing order until 2107!
We have applied an enviROI sort of thinking to fitting solar PV panels or a wind turbine at home, in that we haven't! Instead we've invested some money in a Triodos Bank renewable energy bond, where it will finance wind turbines. These will be put up in, well, windy places, as wind farms are. So the enviROI will be much better than any widget that we could currently fit to our house.....
The carbon cost of building is relatively well-known, I think. By that I mean that if you want to know, then you can find out. One of the big things is cement manufacture (tonne of cement means tonne of CO2, as a rule of thumb). If you don't want to know, then this is politically easy to ignore.
The issue of time and carbon neutrality comes back when you think of PV panels on your CN house, generating most electricity when demand is low, and none when demand is high (winter evenings). Building-mounted wind turbines give very little power in urban areas because they need reasonably strong and (often overlooked) non-tubulent wind.
So a step change in energy efficiency is well within our grasp, but I find it hard to see how a building will generate enough energy on itself to supply its own electricity and pay back the carbon cost of construction.
Perhaps it's a case of the ideal being the enemy of the good!
Our 1930's house's CO2 emissions have come down over the past few years from 5.8 to 3.1 tonnes per year (based on gas and electricity consumed, 0.19 kg per kWh of gas, 0.46 kg per kWh of electricity). These are steady improvements (based on meter readings) year on year due to a condensing boiler, loft insulation, switching things off. And we've just had the cavity walls insulated.....
Lawrence
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