Want to be safe in the event of a fire? Build with wood! Yesterday I took a party of local authority chief executives from Sweden around the ecoDepot. A little anxious before the event because the Swedes are two or three decades ahead of us in most matters environmental. Here in York I talk with architects who tell me that ground source heat pumps are untried and new fangled technology. In Sweden they have been using heat pumps to heat homes for decades and have nearly a third of a million homes heated in this way! | "Most of our Brave New World was their Home Sweet Home" | |
They power buses and trains with bio-ethanol instead of fossil fuels. One of the Swedish delegation even told me that they power buses with gas derived from the city dump. I am hoping they can help us develop bio-diesel here in York. Kristina Peat, the council’s sustainability officer, and I did have something to excite the Swedes – the ecoDepot’s innovative prefabricated straw cladding, of which much is said in previous blogs. As we showed them round the building, it was clear that most of our Brave New World was their Home Sweet Home. With the cedar wood cladding and cedar shingle roof the ecoDepot can even pass for a high tech chalet, to some eyes. ‘The timber frame is made from glulam wood’, I explained as we walked round the building.
‘Yes, yes, I can see,’ came the reply. ‘we have been using this in Sweden for 30 years. It reduces fire risk.’  | | Glulam joists |
In Sweden the insurance bills are lower if you build with a glulam timber frame because, in the event of a major fire, steel melts after an hour whereas glulam simply chars on the surface. Fire crews are not allowed onto a burning roof of a building supported by a steel structure but if the frame is glulam they can walk about safely. Free access to the roof means the fire can be contained more quickly so there is likely to be less damage to the building. Counter-intuitive or what? The roof of the ecoDepot now has solar panels. In a week or so they will all be in place and the scaffolding which has cocooned the building for a couple of months will be removed. Inside work is progressing very quickly. The pre-fabricated straw cladding panels are being lime-rendered. Two or three coats are being applied, with a different finishes internally and externally.  | | Installation of the under-floor heating |
The underfloor heating is currently being laid. As the photo shows the heating is in the form of a red snake of piping which will be encapsulated in concrete. Initial plans for the ecoDepot did not use concrete for the first floor. Concrete is not a great material if you are trying to reduce the CO2 emissions embodied in the buildings construction but it comes into its own as a kind of giant battery or storage radiator.
With the heating going into the pipes embedded in the concrete, the floor itself will be storing, and slowly releasing, the heat for the building. All the calculations as to what our energy bills will be in the ecoDepot are based on the energy requirements of the current, very inefficient, buildings in Foss Islands Road. It is going to be very interesting seeing how the ecoDepot performs through its first winter of operation. I am hoping we will soon have an interactive website up and running so that anyone will be able to see how much power is being generated by the renewable energy sources and how much better the straw panel walls are at insulating than conventional construction. Watch this space. And the Swedes, I hear you ask. How will they help us make progress on environmental sustainability? I pack that into my next blog. Christian Vassie, Energy Champion, City of York Council, 30/8/06 | 
