How about 80% of current non renewable energy use by sector. So if your 3 bed semi used 20,000 kWh/y and now uses 4000 kWh it is low carbon, zero carbon if you generate all your own.

One problem is that the countries infrastructure uses about 5/7th of what we do and we, as individuals, have very little impact on this.

Nick

Why oh why do they say 'low carbon' when what they mean is 'low carbon dioxide' - and e.g. 'high sequestered hydrocarbon' is actually part of 'the answer'?

Yes, I talk about Zero Fuel, meaning purchased fuel, which is something that is quite far-aspirational but means something real to everyone's pocket. That's a subset of Low Energy, which is a subset of Low CO2, which is a subset of Sustainable/non-toxic Resource Use ... But Low Carbon is meaningless!

But ... it would help to know what Low carbon means. It's a stupid name but as menzies says it's got mean more than just energy.

Posted By: bot de pailleLow carbon means low carbon no?

You tell me - did you read

Posted By: fostertomWhy oh why do they say 'low carbon' when what they mean is 'low carbon dioxide' - and e.g. 'high sequestered hydrocarbon' is actually part of 'the answer'?

'Low carbon' is just gobbledegook - no-one emits or consumes carbon - we emit CO2 (bad), consume bio-hydrocarbons (neutral) and petro-hydrocarbons (good as feedstock, bad as fuel) and sequester hydrocarbons (good). 'Carbon' means diamonds and coal.

Why don't we try and define "low carbon".
Not zero carbon.

Would have to decide exactly what we mean though, would it be based on square metreage, volume, type of dwelling, occupancy, when built, potential to generate (and if included), embodied energy, primary or secondary dwelling (second home), how we travel to and from it, the local/national infrastructure supporting it, alternatives, cost, energy types, expected life (of dwelling and occupants/future occupants). Feel free to add to list as this is where one has to start this type of definition.
Then we can decide if we should use the term Carbon or Carbon Dioxide (though there is a straightforward conversion, 44/12).

May have opened a can of worms here but it is all good fun.

Nick

Given that there is no widely accepted definition of 'zero carbon' yet how can there be one for 'low carbon'? (There being no official government response yet to the last consultation round.)

PS. Did anyone else notice that there is yet another new version of the Technical Guide to the Code for Sustainable Homes, the third release in just over a year?

All this, of course, is 'progress'. A group of ten year olds could do better.

And embodied energy of materials/construction process (to be minimised), and sequestered hydrocarbons (to be maximised)- that's in CSH too?

Eh? I thought, when I read it .... that's ridiculous! Hemcrete shd bring a restraint-of-trade action.

Is that because

Posted By: fostertomembodied energy of materials/construction process (to be minimised), and sequestered hydrocarbons (to be maximised)

have trivial effect, over the building's lifetime, compared with 'operation'?

If so, then why do we bother for a moment about the former?

If not, then how could that have been overlooked - and are we happy that in reality it's therefore easy to improve on CSH levels?

So we having trouble defining "Low Carbon"? :)

If true that CO2 'positive cost' on account of operation is 'only' 10%, that doesn't mean that there's 'only' a 10% max saving to be had by changing construction.

The CO2 'positive cost' on account of construction can fairly readily be turned into not just a 'zero cost', but a 'negative cost' with no particular limit, by arranging the construction to sequester more bio-hydrocarbon in its materials, than the CO2 equivalent of same in its transport and assembly. Just ask the likes of Hemcrete - they're well rehearsed about this.

That 90/10 goes nowhere, to justify CSH ignoring this fairly easily realised potential, now or ever.