Harry at Mocoloco writes that it is " a wish come true, part of the American Hardwood Export Council and Benchmark Furniture’s Wish List project that made a series of wishes come true for 10 design legends for the 2014 London Design Festival."
The wish list project makes the case that American hardwoods are sustainable, renewable, energy efficient, non-toxic and healthy, ethical and socially equitable. It would be nice if that were true but much depends on how it is harvested and finished. However you can't argue with this:
The choice of materials is a key component of sustainable design. By using American hardwoods, designers are assured that they are minimising their impact on the environment throughout all the stages of the product life cycle, from extraction, through processing, use, reuse and final disposal.
More at the Wish list
It's not the first rotating shed we have shown on TreeHugger. George Bernard Shaw had one too.