Meredith and Roger were looking at potential partnering arrangements with Schoeb and had a couple of rather more detailed discussions than me. I got a more personal tour, showing how this business had grown from a joinery workshop in Walter Schoeb's garage to become Switzerland's most successful factory house builder, completing around 60 units a year. That's still small by German standards, but compares in scale with UK housebuilders like Oakwrights. Their semi-automated production lines were humming away with Hundeggers and Weinmanns beavering away — I have seen a few of these operations now — with just two or three people overseeing the construction of walls, floors and roof panels. Schoeb are interested in building in the UK and have set up an office in London. They will also be at EcoBuild as part of the Just Swiss stand, so if you want to find out more, check them out there. My impression was that their system is very robust, very well thought out, but may prove to be rather too expensive for the typical UK client. Only those wanting quality — or perhaps a Passive House solution out of a box — need apply. Interestingly, the cost of shipping from Switzerland to the UK only adds around 5% to the factory gate prices: the heaviest component is the timber which has to be imported into the UK in any event.
Some random points of interest. The Swiss have their own energy saving performance standard called Minergie. It comes in various format. Standard Minergie, Minergie P (roughly equivalent to PassivHaus), Minergie P Eco (with other sustainability features like water saving) and Minergie P Eco Plus (with added renewables). Obviously, this system is never going to be of interest to anyone other than the Swiss; it's all rather like the Code for Sustainable Homes in this respect. Yet another reminder as to how good it would be to have a supra-national standard that everyone could understand.
Switzerland seems to be in love with heat pumps. But then their electricity is relatively low carbon, with a mix of nuclear and hydro, including some pumped storage schemes — they do seem to have rather more hills than we do here in East Anglia.
The low energy apartments, called Silence, featured something I hadn't seen before. Phase change glass. GlassX is the name. Apparently, the architect of the apartment scheme, Dietrich Schwarz, happens to be the CEO of GlassX, and therefore has the wherewithal to specify his product because he is the architect. Does this strike you as a little bit unusual? Or maybe that’s usual in Switzerland.
Schoeb the housebuilders rather confirmed this trend too. Generally, their basic spec involves double glazing and no ventilation at all (they open the windows instead when things get stuffy). But the green spec almost always involves triple glazing and mechanical ventilation with heat recovery. It seems that triple glazing is almost a marker for a mechanical ventilation — where you have one, you have the other.
I wonder whether the window manufacter may be missing something: What is the g-value? If this turns out to be to low then net solar gains will be impossible and as a consequence you may be better off sticking with triple.
ReplyDeleteAlso, what is the U-value of the frame? To reduce conductive heat loss it may be more effective to upgrade the frame rather than add an additional (heavy) pane.
It would be interesting to hea what the manufacturer has to say about these issues....
Mark,
ReplyDeleteI didn't see any insulated frames in Switzerland. And I didn't question anyone about g-values. But a centre pane U value of 0.2 is still pretty remarkable. That's better than most new walls (which have a g-value of nothing at all!).
At triple, and even more at quadruple, maybe the future lies in lightweight plastic middle pane(s) like HeatMirror. Wonder how LCA compares? I believe it enables extra-deep single spacer, instead of multiple thinner spacers, to perimeter Ug benefit.
ReplyDeleteBig 3G sliders - did similar size pair meeting on small-mullion corner, ea 2-leaf 2-track 3-bay 8m long (i.e. both leaves sliding away completely from the opening) back in 2002, from Hajom via Swedish Window Co, now defunct. Hajom still specialise in same http://www.hajomskjutdorrar.se/?lang=eng . Just recently obtained quotes for same (sadly cancelled) but even bigger pair meeting on mullionless corner, one 3-leaf 3-track 4-bay 12m long overall, the other 2/2/3 8m long. Hajom unhelpful, Becker http://www.becker-haus.com/en/becker-haus gave fabulous gd price, custom made. The hardware is by G-U, now avail UK from http://www.coastalcsi.co.uk . Best UK price was triple Becker's!