29 May 2010

Grant Shapps to define Zero Carbon. Really?

I learn that new housing minister, Grant Shapps, has said he is about to set in concrete the troublesome Zero Carbon definition. Speaking at an event in Swindon, at Kevin McCloud's eco-housing development there, Shapps is quoted as saying:

"When we were in Opposition I said that I endorsed the concept of building all new homes to a zero carbon standard, and that remains my position. I know how important it is to industry to have a clear definition as soon as possible - so that house builders can buy land with confidence and start to design the homes of the future, and so that the supply chain can gear up production of the technologies that will be needed.

"I will be publishing a final zero carbon definition in a matter of weeks so that the industry can get on and deliver the improved eco-friendly homes we need."

Now, the Code for Sustainable Homes was launched at the tail end of 2006. It promised zero carbon housing within ten years, yet most of the first four years have been spent pondering the definition of what exactly that means. Along comes a bright new broom to sweep away such feeble-minded behaviour. What it is to be the new broom in charge.

But I fear he has inherited a poisoned chalice and hasn't quite grasped its nature. The reason its taken four years of "dithering" is that anyone with half a brain can see that there is not and never can be such a thing as zero carbon housing (at least as long as we continue to burn carbon to power our society), and that the Code for Sustainable Homes was based on a conceit. It was spin of the highest order, based on dodgy carbon accounting and masses of offsetting, so that a housebuilding programme could somehow be branded as "green". About as green as the third runway at Heathrow.

On the other hand, Shapps is also part of a new government that has already dismantled Labour's housing targets. We can only guess, but the probable result here will be that there will be far fewer new homes being built over the coming years. Whilst this may cause problems elsewhere (i.e. the council house waiting lists), it will at least be a far greener policy than promoting mass housebuilding via the Code.

My tip for Grant? Don't even try to define Zero Carbon. As soon as you do, people will start picking holes. You might as well try to boil an egg in a colander. Instead, accept that it's impossible and just promise to keep reviewing Part L, in order to make incremental energy efficiency improvements. No one will argue with that.

24 May 2010

Balkanising the Building Regs

I’m getting hacked off. Again. What’s got my goat this time? It’s the building regs, and the fact that not only are they constantly changing but that we have in our nation three different versions. And this is about to become four, as Wales is set to rest control of its building regs from England very shortly. So it will no longer be the “England & Wales” building regs.

Now I am sure that this gives the politicians in Cardiff a warm glow as its seen as yet another step towards devolution. Like…“We can’t raise our own taxes, but boy can we introduce a few new building regs.” And I happen to know that Wales is going to take this opportunity not only to translate them into native Welsh, but to green them faster than England — as if this is a competition!

But what actually happens is that it creates confusion. For users, for manufacturers, for practitioners. And for journalists writing about these matters.

I can remember sitting in a seminar in Ecobuild this year listening to some guy from the ministry going on about the forthcoming changes to Part G, the water regulations. He mentioned that bath taps are going to have to be thermostatic in future, but that it had been decided that other taps and showers would be left uncontrolled. Then he added that in Scotland, more taps have to be thermostatically controlled. I duly noted this and thought to myself that I was somehow lucky to have such an important and useful piece of information related to me. Not many people would know this.

But just how different? Could I actually be arsed to go and check this out? Well, no, not really, because the very big chances are that I will never ever be involved in installing bathrooms in Scotland. And that whilst a few of my readers might be, I sort of object to having to look up such obscure data on the off chance that some of them might find this vaguely useful.

The truth is that I really don’t want to know about the differences between the Scottish and English and Welsh building regulations. Not to mention the N Irish ones as well. Life is just too fucking short for all this. It’s bad enough having to write about building regulations at all, without having to go all anal and smug and saying “if you think that’s draconian, you should see what you have to do in Scotland” or “whilst in England they have to do x in 2016, in Wales they are going to have something similar (never identical) in place by 2012.”

Who cares?

What we should be moving towards is a pan-European building code. After all the laws of physics are no different in Sicily. The climate and the customs may well be, but the codes are capable of adapting to this very easily. We do it in the UK with our rain exposure maps which show just where you can and can’t install full fill cavity wall insulation. OK, we don’t have big earthquakes here, but there’s nothing stopping you having a section for building in quake zones, and even translating it into Welsh if it makes everyone feel better.

OK, I accept that such a project would be many years away, but for Wales to take off on its own and start up with a new set of regulations seems to me to be moving in completely the wrong direction. The only reason for Wales to have separate building regs is to differentiate themselves from the English. But what is the point of that? If they really wanted to differentiate themselves, why not say “OK guys, we appreciate the power to change our building regs, but lets put common sense in front of small town politicking and lets stay with the one set we already have. We can call them the Welsh building regs, but in reality they will be identical to the current England & Wales version.” Which, ironically, is what the Irish Republic chose to do many years ago, despite having achieved full independence.

What’s doubly weird about all this is that, politically, I fully support the break-up of the UK into separate nations, and the closer integration of us all into Europe. So you could argue that I am being thoroughly inconsistent here. But maybe not, because I also like the idea of a common currency, even though it’s currently in big trouble. I certainly support any moves towards a common set of building regulations. Balkanising the regs is bad news for all of us.

19 May 2010

Some Passive House Maths

What effect do 300mm cavities have on floor area? I’ve just been putting my new benchmark house through its paces and have done a few calculations. As it stands (or rather will — it’s still under construction), it is a four bedroomed detached jobbie on two floors with an internal floor area of 147m2.

It’s basically a brick and block construction with a cavity width of 100mm, designed to be fully filled with DriTherm, designed to give a U value of maybe just under 0.3 (designed to pass Part L 2006 version).

Now if the cavities are widened to 300mm, without any changes being made to the design, the internal floor area falls to just 131m2.

So here it is:
• The external area of the house is 173m2
• The built internal floor area is 147m2 (85%)
• The Passive House version would be 131m2 (75%)

It’s a whole lot of wall, and as such it remains a huge hidden cost of building to very low energy standards.

One conclusion could be that you shouldn’t be designing walls that are 500mm thick, and that it’s time to embrace wall systems which are more efficient.

Another is that you might be able to overcome the space constraints by good design – the Small is Beautiful argument.

Yet another is that when you reduce the process to number crunching metrics (like £x per m2), you inevitably get some strange results and that you shouldn’t take them too seriously.

But next time you read that “Passive Houses only cost slightly more to build than conventional ones”, perhaps you should ask if we are really comparing like with like?

17 May 2010

Scotland Review

Well, I was only there for 33 hours, and I never got further than a very small part of Glasgow surrounding the exhibition centre, so this is obviously not a review of Scotland as such, but I did talk to a lot of people and heard some fascinating stories.

I was approached by two sets of people commissioning Passive Houses, one couple in Aberdeenshire, and a man called Ian who is involved in a plan to build 6 at Findhorn. Passive House really does seem to be in fashion now - lots of people have heard of it and it's gradually moving into the vernacular, although I am still not convinced everybody understands what it really means. The couple from Aberdeen wanted to know the best way to heat a Passive House, and I said I thought the jury was still out but that many people's old favourite, the wood burning stove, would probably blow a hole in the airtightness requirement. Anyone else any thoughts?

I met a couple who run a very proactive Project Management company called Quantum Forth. I was impressed by the service they offer.

And I caught up with Charles Stewart of SIPS Industries whose boundless enthusiasm never ceases to impress. The guy now has SIPS plants in Western Australia and South Africa, as well as his original business in Fife. Charles hails from Zimbabwe and is still very active in raising money for schools in southern Africa, and is also planning to fly across Africa in an Autogyro this summer. Check out Heli2Africa.

Perhaps the best story I came across was a Mr Disgruntled of Edinburgh who is planning to undertake a flat modernisation in that fair city. The job involves putting in an en-suite bathroom and he is in dispute with his building inspector who is insisting that the door is wide enough for wheelchair access, which, for one reason or another, renders his en-suite bathroom unviable. It just so happens that the bedroom door — which you need to go through to access the bathroom — isn't this wide (but then it's already there). And the flat just happens to be on the third floor and there is no lift. But will the building inspector yield? No way. The new door must be compliant. It's good to know that common sense is as thin on the ground in Scotland as it is elsewhere.

10 May 2010

Part L 2010 Lighting changes

The technical details on Part L are now with us and I am slowly getting my head around them. One of the things that stands out is that we now need to refer to supplementary documents and, in particular, to one called the Domestic Building Services Compliance Guide.

Buried away on p 123 of this document is the guidance on lighting, and lo and behold, it’s changed significantly from the guidance in Part L 2006.

What did Part L 2006 call for?
• for 1 in 4 light fittings to be low energy, or for 1 every 25m2
• for all these fittings to be dedicated fittings (no bulb switchovers later on, matey)
• 40 lumens per circuit-watt or better as the definition of low-energy. Almost all fluorescents and some LEDs will meet this.

How does Part L 2010 differ?
• it asks for 3 in every 4 outlets to be low energy
• but it relaxes the requirement for the fittings to be dedicated, meaning that people will be free to switch over to any old bulb after the building is finalled
• the new efficiency threshold is increased to 45 lumens per circuit-watt.

What it means in effect is that it will be extremely difficult to floodlight rooms with halogen downlighters, but much easier for people to ditch all the energy saving bulbs which remain hugely unpopular with consumers. In effect, all the developer has to do is to design a traditional lighting scheme with no dedicated fittings at all, and just put energy saving bulbs in everywhere. Or, for the really skin-flint developer, no bulbs at all.

Hemcrete pour video

Hemcrete pour video taken on the Kent selfbuild site last week.

7 May 2010

On Hemcrete

Yesterday I saw my first Hemcrete house under construction, a large selfbuild in Kent. I managed to get to site to see the hemplime mixture getting fixed to the timber frame background, and to chat to the guys from Denstone Construction who were fixing it. Fascinating talk it was too. Denstone’s expertise is in ICFs but they are happy to try anything innovative. Hemplime is certainly innovative, but is it the future?

Where it scores, of course, is in the low-embodied energy or eCO2 as the manufacturers like to term it. For many people, low-embodied energy materials represent the future of homebuilding, more so than the technically challenging but material-blind standards such as Passive House. But the amount of effort and skill required to wrap this timber-framed in HempLime gave me pause for thought about whether it really represents a step forward. Denstone had had to design and install a shuttering system (pictured) in order to get the insulation into place: they had come up with a system based on plywood sheets held in place by rebated studs which were in turn held in place by extra long screws going into the frame. The insulation then has to be mixed on site (the hemp shiv arrives in bags, and is mixed with a lime binder), hoisted up the scaffolding, poured into place and then patted down gently with a podger.

Then it has to be left to dry. “It’s really a summer job – you wouldn’t want to do this in winter or when it’s too wet.”

On the other hand, it looks great, like nothing else you’ve seen on a building site.