OK, thanks for making that clearer St and Chris, I got it now (brain warming up slowly)

But then isn't this what the "green building" choice is all about and why those that choose the path are more forward thinking than the general population/consumer led commercialism?

Its not about immediate savings/ profit, its about looking to the long term. 12 years doesn't seem that long to me and after that its all good except for the occasional maintenance.

Isn't it about future proofing your family against energy price shocks, or those bitter winters when its a choice of putting the heating on to be comfortable but stressing about the utility bill at the end of it?

I think money put into a well built/insulated/airtight house is going to work far more for you/me in te long term, than putting the money in the bank.

Personally, when I build my house now, its for the long term future free from: 1. a mortgage and 2. being held by the short and curlys of energy prices. in my perhaps misguided mind this might equate to some level of comfort and security.

Thanks Chris, that's interesting. And bad news on the robustness, although I suppose northern European or Japanese makes might be expected to do better (Japan has a very large temperature variation between summer and winter, and in the west and north it gets much colder than in the UK). I've actually got a Japanese friend digging around for any interesting Japanese field data. They've been using these things for yonks, so there should be some.

On the time horizon question, I agree with ferdinand I think. I reckon households will invest in green measures, but often only if the economics are reasonably good. And while some may be able to take a long term view, I do think that many, if not most, will want paybacks of not much more than five years, and ideally less. There's Ferdinand's moving point, but also people are just generally fairly short termist. Jam tomorrow just feels so much less valuable than jam today.

A further point is Jam Today.

That is, if presented with two new houses to buy for £x (say £200,000), and it is a four bed with double garage to normal spec, or a three bed with single garage to PH spec, then most will go for the storage and the extra room. If the PH premium is 5%-10% or so, that may be roughly where we are.

Or may have no choice due to number of children or resident grandparent.

That equation will change with energy (or other) prices going up, but I'd suggest that payback would need to be within very few years (say 5-6) to make the benefit big enough on the horizon to sell itself. Perhaps you could afford to charge £10k more if it was going to save £2k a year.

Much as I *hate* over-regulation, increasing technical building performance standards makes a lot of sense here *provided* that unnecessary overheads have been pared back first. That is a point always missed by kneejerk paperwork enthusiasts.

For old-build, I still think EPC-linked differential stamp duty rates have a lot to commend them.

I don't see any prospect of regulation being trimmed further though; I think that even Eric "Bloodaxe the Gonk" Pickles may have hit his limit.

And there's the small matter of RDSAP not flagging up running costs properly, which hardly helps.

F

>Ironically it would be the prospect of selling that would probably demand that I install a heat pump as even though our running costs are low the market would react badly to a house being heated by direct electricity.

Yep. Also ironically I'm just putting a (planned not to be used) lecky underfloor heating mat in our conservatory for that same marketing reason, which is arguably reprehensible but there was no way short of 5x the cost to extend the other system. Neither is strictly necessary. I have also made provision for it to be a potential small overheat dump should we install solar, as it is on the North side next to a cool lounge, and we could grow exotics.

The same goes for future new builds should I win my current planning battle (now at Appeal). PH-ish standards (prob non-certified) would be an aim, but could I sell them in future with no central heating?

What is the environmental cost of unused fallback provision in eco-houses ? :-).

Ferdinand