wouldn't they be one in the same

Tony,

can you define low energy, a low running cost or a low carbon.

Jonti

We went for low running cost.
Not so much for saving money but mainly for the engineering challenge of aiming for decent/best running efficiency.

Everything from excessive concrete to not the most environmentally friendly PV panels means our build is perhaps only really eco in the longer term. I haven't worked it out. Was far more concerned about heat loss and energy sources other than oil (no mains gas here).

It takes all sorts I suppose. At least we put some thought into it.

Thanks for the explanation Tony. Oh no, my mistake you answered your own question

Jonti

Posted By: tonyLow carbon especially when combustion is involved is worst for the environment.

What “low carbon” when combustion is not involved is worst for the environment?

Agreed that combustion of low carbon fuels (i.e., fuels which add less carbon to the environment) are likely to be worse for the immediate environment (kilometres to 100s of kilometres) in the short term (weeks to months). E.g, burning wood is likely to produce more particulate problems than burning natural gas.

However, there is the ethical issue that those who suffer from the direct particulate, etc, effects are those in broadly the same society who benefit directly or indirectly from the results. E.g., if people are burning gas which is lower cost than wood then they need lower wages so the costs of goods to others can be lower. On the other hand, those who are harmed by carbon emissions may be anywhere on Earth and over a period of centuries and so gain almost no benefit while paying the costs. E.g., a Bangladeshi family who have to abandon their farm in 2080 due to sea-level rise is not likely to have benefited enough to compensate from somebody burning gas rather than wood in England in 2014.

Posted By: tonyLow running cost wins as money is a resource too and has a lot of the benefits of low energy

Money is not a resource, it's a means of allocating resources. If people spend less on heating is there not a risk of them spending more on something else?

(I'm not arguing that people should be made to pay more for heating in order to make them spend less on other stuff - just that focusing on the monetary aspects is likely to have perverse effects environmentally. Also, of course those who really need to spend money on other things should be helped - full marks for Tony's efforts in Reading to deal with atrociously bad insulation on some houses.)

but what if it was very low energy like PH or Minergie, LEED etc with no combustion appliances?

The last two posts show why I asked my question the 4th post on this thread.

Tony, you need to define what you are asking much better as it can mean many different things in its present form.

Jonti

Your question so no

Low carbon can still be pretty bad for the environment without combustion Tony. Take badly designed hydro schemes that submerge lots of vegetation, which decays anaerobically and releases methane, for example. That's a GHG nightmare, but very low carbon. Nuclear is low carbon and non-combustion, but high level wastes aren't fun.

We get far too obsessed with carbon. You can't just focus on carbon if you want to be green.

Low energy should be the first priority. That minimises all impacts. Unfortunately the realities of the market mean that low cost is generally the top priority.