28 Jul 2011

The Salford Low Energy Homes

I found this piece fascinating. In the late 1970s, Salford Council hit upon the idea of building some low energy houses. They weren't the only ones. We did things like that in the 1970s. They were duly monitored for a couple of years, broadly found to work just fine, and then quietly forgotten about for the next 30 years.

Then a couple of years ago, Salford University cobbled together some money to undertake a follow up study. They had trouble identifying the 250-odd homes as no one had kept any records, but they tracked enough down to make a decent fist of it. The houses followed the high thermal mass cocooned in a 200mm shell of insulation design, the sort of thing that isn't going to crumble away anytime soon, and were built for about 8% more than the standard prevailing at the time.

What they have found is that the space heating performance of these homes remains spot on. In fact, it actually beats the figures for the 2010 building regs, and is probably about the same as the level set by the proposed 2016 "zero carbon" standards.

It makes for a good headline, but the colourful graphs used in the study are a little indefinite for my liking. There are no absolute measurements of energy use, just comparitors with other standards such as Part L at various stages. The sooner we convert all these standards to kWh/m2/a the better. Without a common denominator, the results are too easy to manipulate.

Another interesting statement:
The 1980-82 study involved detailed temperature monitoring at half-hour intervals in six dwellings over two years. It produced detailed results which showed that consumptions by different households varied by about a factor of five, from about 10% to 50% of traditional with an average of near 25%.

This corresponds with the observations of many others. There are huge variations on how individual homes perform. The Salford study suggests that the difference is largely down to the temperatures that people choose to heat their homes to, and that a house heated to 23°C would use four times as much as one heated to 18°C. They also suggest that that is true for badly built homes as much as well built ones. If this is true (and it seems likely, though once again there is no way of verifying it), then it has huge implications for the Fuel Poverty debate. The definition of fuel poverty is that you spend more than 10% of your income on energy bills, but without an effective way of monitoring how a household consumes energy, it's pretty meaningless.

26 Jul 2011

The Selfbuild Nugget

From tiny acorns....

There it is, buried on line 13 of Clause 28 of the newly published National Planning Policy Framework, the phrase that we hope will turn the tide of the UK housebuilding scene.

To paraphrase for those of you too lazy to download. Clause 28 deals with Housing Requirements. It asks that individual local authorities undertake assessments of what their housing requirements are. Nothing new there. It is more specific than this though. It requests these assessments address the need for all types of housing, including affordable housing and the needs of different groups in the community (such as families with children, older people, disabled people, service families and people wishing to build their own homes) and caters for housing demand and the scale of housing supply necessary to meet this demand.

So that's what we have won. Just the mention of people wishing to build their own homes. Never been mentioned before in all the 1,000 plus pages of PPG this and PPS that. Instead we have got it into the 60-page NPPF. BTW, how brilliant is that? Just 60 pages. I approve.

So the next stage is to use this lever to campaign LA's to address the demand for selfbuild, and to not quietly ignore it. It won't be an overnight sensation, that's for sure, but we have at least established credibility with the national planners that selfbuild should be more than just a side show.

It already looks as though the draft NPPF is going to kickstart a debate about the Green Belts. Just this morning, I heard the first salvo on the radio from the National Trust who are upset about the presumption in favour of sustainable development. I am sure I even heard the phrase "urban sprawl" came up. Don't you love it?

25 Jul 2011

The Selfbuild Revolution

It's been months in the making but the NASBA selfbuild action plan is now a reality and its here. It seems to be enjoying the support of housing minister Grant Shapps and there is every hope that at least some of the proposals will see the light of day.

I was responsible for the Regulation and Red Tape bits (broadly pages 14 - 17) but I couldn't have done it without the input from the committee members who sat through four meetings at Department for Communities and Local Government in London. So my own vote of thanks to:

David Dewart of Swindon BC Planning Dept
Julian Owen, Architect and founder of ASBA
Roy Speer of Speer Dade Planning Consultants
Sally Tagg of Foxley Tagg Planning Consultants
Doug Livingstone of HCA

and also to Mario Wolf, Paul Wren and Alex Lessware of the DCLG team. There were many others but the ones I have listed sat through every minute of every meeting and deserve medals if nothing else. And of course, a big hand to Ted Stevens, the founder of Nasba, without whom none of this would have happened.

One thing we were all agreed on is that we would like to see more selfbuild in the UK. "Whatever it is they do in Germany (last year 92,000 individual selfbuilds, as opposed to around 15,000 in the UK), we would like some of that pixie dust to rub off on us. It seems that the differences are as much cultural as legalistic and we hope that by gently prodding our local authority planning departments, we could open the door to far more land being made available for selfbuild. Our first goal is to get a mention of selfbuild in the forthcoming National Planning Policy Framework consultation document which is due out any day. This is an amalgamation of all the previous PPS and PPG documents that have made up national policy before, none of which has ever mentioned selfbuild at all.

11 Jul 2011


Cambridge is known throughout Europe as Start-Up Alley. All these whacky, sometimes nerdy boys coming through with their PHDs in things mere mortals can barely comprehend are encouraged to commercialise their research and to form companies with Greek-sounding names to market their work. Mostly this sort of thing goes on in the quiet of a science park, of which there are a number dotted around the town, but every now and then you come face to face with one and this Saturday, Hamish Stuart of Polysolar was displaying his invention at the French Fair on Parker's Piece, close to the main shopping streets.

Now, if I got it correctly, Polysolar is a new type of photovoltaic panel which is formed by etching the power-generating circuits into a sheet of glass, and then sandwiching it between two more sheets. Compared with the crystalline PV panels which dominate the industry, its dead simple and therefore potentially very cheap. It produces less power than conventional PV but it has the potential to be used as a roofing material or as a facade. Building Integrated PV, or BIPV. There's a new acronym for you.

They have already completed several installations in Taiwan and China, but they now have sorted MCS accreditation and are ready to hit the UK, as it's all eligible for the feed-in tariff.

And I only went there to get a baguette for breakfast.

6 Jul 2011

The Natural House?

Good to see that The Natural House is open. At last. As far as I recall, it was meant to be up and running for BRE's Onsite 09 exhibition, but it had run into a few problems. I think the original builders went bust and it took a while to sort out a replacement crew. On time, on budget, it isn't. But is it on message?

I haven't seen it in its finished state (your roving reporter having temporarily stopped roving) but judging by Hattie Hartman's Footprint piece, I am puzzled by what point it's trying to make. The conclusion I am drawn to make is that this is a right-wing house, sitting in a small estate (OK Innovation Park) of left-wing houses. It is also a vocal house, making a statement about its political credentials. "I'm different and I don't care who knows it. Something 'bout me is not the same."

Enter Grant Shapps, our Housing Minister, who was on hand to open the house. Note it's red tape he is cutting, not blue ribbon!
Very symbolic. His quote is also illuminating. Shapps said ‘delivering zero carbon was beginning to look quite alien and not synonymous with traditional looking homes. . . Natural House demonstrates that British design will still have a place on our streets and does not need to be replaced by Scandinavian-style, ‘eco-bling’ properties that wear their green credentials for all to see’.

Now hold on Grant. One thing at a time. Firstly, is this really what anyone would call "British Design." I'm really not sure. Although it's four square, faintly Georgian, it's also nothing like anything I have seen anywhere in the world. If you were to show me a picture of this house without knowing where or what it is, and had asked me to guess where it was, I think I would go for Germany, probably because the windows look German (in fact they are Austrian, quite close). I'm not even sure what a modern British house design looks like.

By implication, Shapps seems to be implying that the other houses on the BRE Innovation Park look Scandinavian, but once again I'm not sure that really holds water. One or two maybe - indeed one of them is Scandinavian IIRC. But mostly they look.....left-wing methinks. Or modern. I guess Scandinavia is pretty left wing. Certainly has very high public spending levels. Not to mention suicide levels - how existential can you get? There is a point to be teased out here, but I'm not sure it's Britain v Scandinavia.

Then there's the eco-bling comment. One of the things that the Natural House eschews is eco-bling, which is the derogatory term used for solar panels in particular, but also for all the various accoutrements which the government currently gives us subsidies for (i.e. heat pumps, biomass boilers, CHP plants, i.e. small scale renewables generally). Although the Natural House is not a PassivHaus, it's making much the same points — i.e. you don't need eco-bling, you just need to build it properly. No whether this is a left v right, modern v traditional battle, I have no idea, but it's a point to which I pretty much subscribe. Maybe that makes me right-wing?

The manifesto for the Natural House includes using not only "natural" materials but ones that can be sourced in the UK and ones that can be purchased off the shelf. Which shelf, it doesn't say? Harrods anyone? Eagle-eyed readers will already have spotted that the windows came from Austria (despite Howarth Timber now making them in Lincolnshire), but it also uses Thermoplan clay blocks for the walls (Germany), Pavaroof (Switzerland), Aereco ventilation (France), lots of timber (anywhere but the UK). At least the foundations (Bullivants) and the roof cover (Sandtoft) are British, plus much of the chintzy fit out.

And how is it heated? Hattie doesn't tell us. Nor does any of the other literature I can lay my hands on. It's certainly no post-heated MVHR system because it doesn't have an MVHR system - it relies on Aereco's passive stack system instead. Certainly won't be a heat pump. can't be a gas boiler? Can it? My guess is that it's some infernal biomass boiler, hidden away in the servants quarters. I bet you it's made nearer to Scandinavia than the UK! (But I won't mention eco-****).

So we are getting close to the knitty gritty of what this house is all about here. It shares a fabric-first approach with the PassivHaus — incidentally there is as yet no PassivHaus on the BRE Innovation Park — but it sets itself out as being diametrically opposed to the PassivHaus airtight/MVHR approach. Because? Well, it's not altogether clear. I guess because it's "unnatural". But they have in fact — according to the score sheet — built an amazingly airtight house with a score of just 1q50, which only narrowly fails the PassivHaus standard (0.6q50). That's an awfully tight score for a house with no MVHR and it will be interesting to see how it performs, especially if there is to be wood-burning appliances as well. My guess is it will struggle - or else there are vent holes which will be used to let extra air in which simply got closed off for the pressure test. Something doesn't add up here.

You see, if you go really airtight, you more or less have to install MVHR. I know some people disagree (Bill Dunster?), but the consensus of opinion is that if you construct something resembling an aircraft cabin, then you need to have a fan to change the air. Maybe someone, somewhere on some distant university campus will spend years testing ventilation systems and airtightness levels to get a conclusive answer to all this, but at the moment it's an unknown and MVHR is much the simplest way of dealing with this unresolved issue.

So why make a stand against using MVHR? Is it because it's eco-****? Is it because it's not natural? Is it because it doesn't breathe? (Give us a break, please!) Is it because it's left wing? Or Scandinavian? Is it because we like chimneys? But if we like chimneys, why bother to build to such low air tightness levels? And why does this blog keep ending with a series or questions?

1 Jul 2011

On Welsh Slate

Alan Smith, MD of Welsh Slate, had invited me to take a look around the famous Penrhyn slate quarry.

I got there at last on Tuesday and was immediately bowled over by the place. The scale — it's enormous. The location — it's dramatic, perched up on a mountainside at the edge of Snowdonia. The history — it's all pervasive and a little disquieting. Penrhyn has been operating for hundreds of years so comes with the feel of an industrial museum piece. But there are still hundreds of years worth of unworked seams lying in the ground, so it remains an incredibly important resource. And one which I slowly came to realise is both underused and undervalued.

My knowledge of the UK roofing market is fairly limited. Back in my days as a jobbing builder in Cambridge, we regularly used to do re-roofs of the Victorian housing and we always used to search out Welsh reclaims. This was in the 1980s, at a time when Spanish slates were just starting to appear in number. Reclaims you could buy for a similar amount but were by and large a better bet than the Spanish ones. Thinking about it, that in itself is pretty amazing, because these reclaims had already spent the best part of a century up on a roof, and they were still in pretty good nick. It was easy to test them. You just tapped the back of the slate with a hammer and if it gave a nice hollow ringing sound, it was a good'un. In a good batch, only about 5% were rejected. Any building product with a 95% recycling rate after 100 years has got to be pretty special, but back then we just took it for granted. In contrast, many of the imported slates were prone to cracking or splitting when being nailed on the battens.

Back then, we never went for new Welsh slate because there was no need. It was always said to be "too expensive" so we just went with what everybody else used, which was reclaims.

But I never really put 2 + 2 together before this week. There is a very good reason why new Welsh slate is "too expensive" and that is because after 100 years it is still better than most slate from other quarries around the world. And that's not an idle boast, it's pretty much down to the geology of Penrhyn. The slate hewn from this seam is a lot older than the competition (geoglogically, it's Cambrian) and because of this it has far fewer impurities. Consequently, it is harder and it barely degrades. It can sit on a roof, go through whatever sun, wind,rain and snow can throw at it for year after year and it barely has any effect on it at all. Thinking back on it, the roofs we were relaying in the 1980s were being relaid because the supporting timber was knackered and the slates were starting to slip. It wasn't the slates themselves which were at fault.

Even today, 100 yr old reclaimed Welsh slate is available to buy at around £28/m2: new Penrhyn slate costs around £50/m2, so this is a building product that holds 60% of its value for a century. Can you think of anything else to match this? In terms of whole life costing, it's an astonishing result. And looking at things this way, I realised this week for the first time that new Welsh slate isn't "expensive" at all. It's actually one of the biggest bargains out there.

By the end of my brief visit, I had become an advocate. In an era when everyone and their aunt is banging on about sustainable building materials, here is one that's produced on our doorstep, that lasts several lifetimes, looks fantastic, there's masses of it, and it requires almost no energy to produce. There's no baking, no firing, no moulding with cement, no manufacturing at all. Just sawing away from the rockface, cutting, splitting and finishing, much of this still done by hand because no one has yet invented a machine which can improve on the human eye. Go check it out.