Thursday, February 21, 2008

GD Fever

What are these people watching? It’s a Wednesday night in Cambridge, there is European football on ITV and Sky, but no, they are not watching the footie. The Brit Awards are also on featuring Sharon Osbourne swearing at Vic Reeves, but they aren’t watching that either.

They are all gathered here to watch Grand Designs. Could this be the start of a new trend? The subject of the programme was an extraordinary house being built on a steep hillside in Bath and this particular group was brought together by Baufritz who supplied the above ground parts of the structure in the programme. Being a super efficient German housebuilding operation, they were pretty confident that Kevin McCloud was going to be complimentary and they invited a group of friends, prospective clients and staff along for beer and nibbles.

So were they over the moon? Or sick as a parrot? “Too much of the programme was spent on the groundworks” was a frequently heard observation, along with “Tiffany was magnificent” and “I never knew a staircase could be a thing of such beauty.” And no doubt about this result: England 0 Germany 2.

Wednesday, February 20, 2008


I have been lead to believe, and I think Mr Brinkley will confirm, that there are no house in the UK built to the German Passivhaus standard. I think Mr Brinkley was considering building one but I don’t know if he has done it. In any event, I have just come across what I believe to be the first.

It is actually 2 flats, a 1-bedroom and 2-bedroom, built in the inner city of Cardiff, by an Italian lady. The lady is in fact an architect, educated in Munich, so it is perhaps less surprising that she adopted the Passivhaus standard.

The property is a very contemporary looking house, built in the quiet cul-de-sacs of the Roath area of Cardiff. It has a slightly surreal feel being surrounded as it is by Victorian terraces. The 2 properties next door are also modern-looking but in a more traditional way, which helps to soften the impact of the house.

For those that don’t know the Passivhaus standard was established by the Passivhaus Istitut in Darmstadt, Germany is 1996. Since then around 6,000 houses have been built and certified to the standard, across Europe and the USA. What Passivhaus means, in broad terms, is that the building is insulated to a level that allows the sun and other passive heat gains to produce enough energy to heat the home. Passive gain is the heat from daily activity, given off by people, cooking, the shower, making toast, boiling the kettle. Pretty much everything we do produces heat which can be captured and circulated from warmer rooms (bathroom and kitchen) to cooler rooms (lounge and bedroom) by a heat recovery and ventilation system. Passive solar heat always plays a big role in this design of house and, as is typical, this house has a south-facing wall that is entirely glazed. These are triple-glazed sliding doors that give good access to the garden in summer but allow heat to be captured in winter. They have a U-value of less than 1 compared to 1.8 for the best double-glazed windows.

On the day I visited, the outside air temperature was 50C. The temperature inside was a very comfy 190C. This is a little lower than the typical central heated house, indeed my office is at this moment 210C, but feels cooler than the Cardiff house. This is attributed to the walls of the Cardiff house being lined in plywood. The lady who built it said “wood gives off less coolth than stone”. And I believe her. Mine is a stone cottage and the walls are cool to the touch. Her walls felt warm.

This house has a has a number of remarkable features.

1. It has no heating. No boiler, no fireplace, no stove, no fan heater, nothing. And it is warm.
2. It is a timber-frame house built entirely by local labour. It is not a pre-fab manufactured by hyper-efficient German engineers. She used ordinary Welsh builders with no special skills and no special knowledge. In fact these guys were learning on the job, which did lead to a bit of budget and schedule over-run.
3. The house came in at around £1,200 per m². Which may be a bit high for the standard of finish achieved, but is within bounds and would show a profit if she sold it.
4. The house has lots of solar energy on the roof, both thermal which generates around 70% of her hot water, and PV which generates about 50% of her electrical demand (and these are included in the £1,200 per m²)
5. The whole house, every last detail, is recyclable. Further, most of it is reusable, i.e. it has been built in such a way as to be immediately removable, without damage, to be re-used in another house.
6. She has installed rainwater harvesting to reduce her water consumption from the mains to less than half the normal.

A house that needs no heating needs a lot of insulation. This house has 380mm in the walls, 200mm under the floor and 430mm in the roof. This insulation is all hemp, which has low embodied energy and ever sequesters CO2. This compares to the normal UK standard of 90mm in the walls, 75mm under the floor and 270mm in the roof. In also needs a very high level of air-tightness to prevent heat losses from air movement, and that is where the contractors encountered most of their problems. They were just not used to building to these levels of precision and had to re-do a fair bit of the work.

The point of all this is that it can be done. What this lady has proved is that a self-builder can build a highly efficient house, with trivial running costs (she estimates her annual energy bill at less than £200) without recourse to specialist materials or suppliers. Under the Code for Sustainable Homes the house would easily reach level 4 and maybe level 5.

What she has shown is that all the bleating from the house building industry that zero carbon is unachievable is nonsense. If the process that this lady has pioneered were taken up by the big companies it could be lifted to level 6 and zero carbon emissions without too much trouble. And bring in affordable, sustainable and profitable houses. Is it not time that the house building industry stopped whinging and got on with building the houses we need?

Climbing on a Sustainable Bandwagon

I have just had the rare privilege of attending an RIBA accredited seminar on “Innovation in Natural Ventilation”. For a sustainable building guy like me that is hot stuff. In these days of passive houses, ultra high insulation and ultra low air movement, Innovation in Natural Ventilation is just what I need.

So I duly pitch-up to the local college, full of anticipation for a couple of hours deeply immersed in thermal stacks, heat plumes, low pressure zones, thermal atria and natural convection. What did we get – a bloke selling windows.

A very nice bloke, who knows a lot about windows, but then there is only so much you can know about windows. He did tell us about a new window – parallel opening rather than top, bottom or side hung. Which was interesting for about 15 seconds but struggled to fill a 2 hours seminar.

The bloke’s sole claim for the sustainability of his windows was that opening a window means putting less cooling into the property. Which even he agreed was a bit thin in terms of sustainability credentials. These are, after all, glass panes in an aluminium and stainless steel frame. None or which are particularly sustainable.

By the end of the seminar the issue that was really making me cross was the title of the seminar. It had only one word of truth in it. There was no innovation (parallel opening windows might be an interesting spin but we have had sliding sashes for quite some time) and nothing natural. True, windows provide ventilation but that hardly warrants a 2 hour RIBA accredited seminar.

This was, in truth, another example of the double glazing industry finding a new way of selling an old product.

My view is that sustainability is a serious issue. Maybe I am bound to say that, but why wouldn’t I? I make a living from untangling the conflicting and often misleading information provided by companies purporting to offer a sustainable product. The Windsave wind turbine is a case in point. At £1,200 for your own micro-generation plant it looked like a good idea. The fact that it fundamentally does not work in the way the manufacturer’s suggest caused all sorts of people all sorts of problems, but didn’t seem to worry the manufacturers too much. Or the DTI who spent so much in grants for this one machine that it brought the whole grant scheme for all renewable energy technology crashing down.

Sustainability is said to be “meeting the needs of the current generation without impacting on the ability of future generations to meet their own needs”. If the domestic housing industry is going to change to meet this challenge it has to be on the back of good information, with products that are truly innovative and that really are sustainable.

Maybe it is time for labelling! The BRE produce a guide to sustainable specification and RIBA have accredited this course. Maybe it is time for a star rating system for sustainable products so that the consumer (and the professional specifier) know what the real credentials of any product are. My guess is that the windows I saw today would struggle to get a single star, while wooden sliding sashes would be up at a 4 star rating.

Thursday, February 07, 2008

Are these no heat homes?

“We are building homes with no heating systems already.” That was the bold claim made to me by Andy Porter of SIPS@CLAYS at the Harrogate Homebuilding & Renovating show back in November.

“Well, if you are, I’d like to see one,” I replied.

And so it came to pass that on Wednesday of last week, I met up with Andy and he took me to see two of their newly completed homes, one near Beverley in Yorkshire and the other in Accrington, Lancs, both of them what I would call classic selfbuilds.

Both homes had been constructed with Kingspan Tek SIPS panels, 142mm thick, with a U value of 0.2. This is hardly surprising as this is the construction system that SIPS@CLAYS specialise in — they were one of the original Kingspan Tek project partners. One of the houses was double glazed, the other used imported Swedish triple glazing, and both had been fitted with mechanical ventilation with heat recovery (MVHR). Neither house had anything in the way of conventional space heating, but both had wood burning stoves and both had solar thermal panels on the roof.

And what were they like to live in? Had they been cold during our recent cold snaps? Were the residents togged up with woolly hats and scarves, regretting their decision to be so bold as to do away with space heating?

Joan Barker, the builder of the house near Beverley, was still in the process of finishing off the house. She and her husband had moved in about a week before my visit (when it was really cold) and she said that it had been a little chilly for the first two days right after the move, and she admitted to using a couple of 2kW convector heaters to get up to comfort. But since then, no extra heating at all: and the wood burner was only being lit in the evenings. I would have said that she was already one happy bunny, and felt vindicated by her decision to do away with radiators and/or underfloor heating.

In Accrington, David and Jane Hartley had been living in their home since the summer and had had longer to figure out how it was responding. They kept their multifuel Dunsley stove going throughout the winter months (using coal only at night to keep it going) and the MVHR system distributed the heat around the house quite effectively. The room temperatures varied between 14°C and 18°C — not warm by current central heating standards but they found it quite comfortable. Although the stove is located in the middle of the large central living area downstairs, they tended to spend much of their evenings in an upstairs lounge and they noticed that the temperatures were more even upstairs than downstairs, where two of the peripheral rooms were noticeably cooler than the main living area where the stove is. This may be an effect of the uneven distribution of heat via the MVHR ducting.

So have they done it? Are these no heat homes, or are they merely modern variations of houses that might have been built in Beverley and Accrington 100 years ago, heated by solid fuel fires? Are we simply using modern technology (fans and ducting) to shift heat around a house more effectively? These are all interesting questions which I am not sure I can provide a coherent answer to just yet. But in the absence of any genuine Passive Houses in the UK thus far, these SIPs homes stand out as being as close to the new paradigm as we are likely to get in the next few years (being super insulated, pretty airtight, and mechanically ventilated) and they do look to be providing comfortable living conditions with a minimal energy input, which is after all what this low energy thing is all about. I guess the success or failure of these schemes should ultimately be assessed by the size of their fuel bills and in neither instance had they been in occupation long enough to make a judgement on this.