Fw: UK_Selfbuild Cheap Zero Heat House

[dicegeorge at hotmail dot com]

Sent: Thursday, April 29, 2010 3:37 PM
To: <UK_Selfbuild at yahoogroups.co.uk>
Subject: UK_Selfbuild Cheap Zero Heat House

> In a Somerset village, a builder is creating zero-carbon homes for less 
> than the cost of conventional ones.
>
> By Ashley Seager The Observer
> Sunday August 16 2009
>
> It's unlikely that you would turn up at a pretty, quiet Somerset village 
> in search of any kind of revolution. In fact, you'd be hard pushed to spot 
> anything revolutionary in the village of Chewton Mendip, save perhaps for 
> a few solar panels on top of the local school.
>
> Blink and you'd miss three terraced houses forming a corner of two streets 
> in the village. They blend in perfectly with the other traditional stone 
> houses. But behind the facades lie brand new homes built with ultra-modern 
> materials and which already meet the government's strict zero-carbon 
> rating that all new houses will have to meet from 2016.
>
> And, crucially, they have been built to a comparable cost to conventional 
> houses, blowing away in an instant the claims of the big housebuilders 
> that meeting the 2016 target will entail huge cost and put up property 
> prices.
> It's generally true that in any industry, innovation comes from the small 
> start-ups rather than the big incumbents, and local builder Arthur Bland, 
> combining for the first time some advanced new floor, wall and roof 
> technologies already available in Britain, is proving the point.
>
> "These are the most thermally efficient houses built in the UK in 2008 and 
> are twice as good as the PassivHaus [energy efficiency standard] in 
> Germany," says Bland. "And if I had built them on a larger scale on a 
> larger plot, they would have been cheaper to build than conventional 
> houses; I am quite sure of that."
>
> They say the three most important things in building an eco-house are 
> insulation, insulation, insulation. And maybe airtightness too. And that 
> is what Bland's house embodies: it is so efficient at retaining heat that 
> it does not need any form of heating. In an English house? Surely some 
> mistake?
>
> Bland explains that the revolutionary insulated floor system, from a 
> company called Ecoslab, combined with a polystyrene-and-concrete wall 
> system from Logix and a roof system from Unilin, give the house a "thermal 
> envelope" from which heat and air cannot escape. Daily living generates 
> enough heat - from  TVs, kettles, the warm backs of fridges and the people 
> who live in it - that no further source is needed.
>
> Airtightness might sound suffocating, but in fact the houses have a 
> circulation system that changes the air five times an hour. And the clever 
> bit is an  exchanger that captures the warmth from stale air, which is 
> extracted from the house by vents, and reuses it to heat water and the air 
> in the rooms. That system is made by a Swedish company called Genvex and 
> costs about £6,000 to install - but once you deduct the cost of a 
> traditional heating and hot water systems, Bland says you are left with a 
> negligible extra cost per house of £500. For the homeowner, the advantage 
> of Genvex systems is that they last much longer than traditional boilers, 
> which need replacing at least every 10 years.
>
> The windows are all triple-glazed and wood-framed to keep heat in. They 
> can, of course, be opened if the house gets too hot in the summer but the 
> Genvex will also provide cool air to keep the places at a constant 
> temperature.
>
> The windows and walls are also very good at keeping sound out - a 
> significant advantage for future homes being built on brownfield sites 
> near other houses and roads. The absence of radiators leaves walls freer 
> than they would have been and the airtightness, if nothing else, means 
> there are no nasty draughts in the winter.
>
> Bland's former wife Linda lives in the middle house with her two children 
> and loves it. She moved in last December when it was completed and so 
> tested it through the cold snow of the spring, when temperatures dropped 
> to -9C.
>
> "For a few days I had a small electric heater on in the living room just 
> to raise the temperature a bit. But after half an hour the house was too 
> hot and I had to turn it off," she says.
>
> "It is a great house to live in and I have no complaints at all. The air 
> does feel dry, though, and I have to water the plants more than I would 
> have done. But that is the only thing I would say. I don't have to lug 
> solid fuel around any more like I used to in other houses I have lived in 
> so I love it."
>
> The house has low-energy lightbulbs, not only because they consume less 
> electricity but also, explains Bland, because the heat from conventional 
> ones would make the house too hot.
>
> He points out that the best thing to do when you have had a bath is to 
> leave the hot water in it to cool, since the heat will be sucked through 
> the bathroom's vents and recycled by the Genvex system into more hot 
> water. "You can get obsessed by this heat business - but it is important," 
> he says.
>
> The three houses share a rainwater harvesting system via a big tank in the 
> communal garden to the rear. The rainwater is used for dishwashers, 
> washing machines and toilets. About 75% of the houses' annual water 
> consumption is provided in this way.
>
> The houses are not yet zero-carbon in the true sense of the phrase since 
> the planning laws in the village's conservation area prohibit the use of 
> renewable energies such as solar panels or wind turbines. As a result, 
> each uses about £600 a year of electricity from conventional sources.
>
> But Bland stresses that the houses meet all the Code Level 6 requirements 
> of the government's code for sustainable homes - a set of rules which is 
> gradually tightening the regulations for new buildings to reduce their 
> carbon output - in terms of the construction.
>
> The addition of, say, solar photovoltaic panels would easily make them 
> zero-carbon or even carbon-negative in the sense that they generate more 
> clean energy than the consume, exporting the surplus to the grid.
>
> The building cost for the three houses was £300,000 for a total dwelling 
> space of 280 square metres. That sort of figure - about £1,100 a 
> square metre - should make the big housebuilders sit up and take notice, 
> especially as Bland says the awkward plot shape and stone frontage added 
> about 20% to his costs. In other words, slightly more standard houses 
> would be cheaper than conventional dwellings even if the solar panels were 
> added on. His system is also quicker than conventional housebuilding.
>
> "There is no great mystery to building houses. If I had not faced the 
> constraints I did on this project, I could easily come in cheaper than 
> conventional houses," he says. "I have simply put some new kinds of 
> products and processes together for the first time. But they can be used 
> flexibly to create any kind of building."
>
> But the big boys, of course, don't like change. Bland took his system to 
> the Ministry of Defence, who had a long-running contract with a volume 
> housebuilder for homes for service personnel. The big housebuilder is 
> charging the MoD £2,000 per square metre for the homes - a high price - 
> and was, not surprisingly, impervious to the MoD's request to copy Bland's 
> model, which would have saved the public purse money both in construction 
> and running costs.
>
> Although producing concrete needs a lot of energy, the Bland houses use 
> much less than traditional houses and require many fewer truck journeys, 
> saving on emissions as well as noise and disturbance - because they use 
> the excavated earth from the foundations as a base for the Ecoslab floor 
> system instead of carting it away to landfill.
>
> You no longer have to imagine the future of housebuilding. It is already 
> here.
>
>
>
> ------------------------------------
>
> To unsubscribe from this group, send an email to:
> UK_Selfbuild-unsubscribe at yahoogroups.co.uk
> The FAQ is available at: http://www.borpin.co.uk
> To contact the moderator eMail: Rick_Hughes at btconnect.com
> Yahoo! Groups Links
>
>
>
>