Little on this new National Conservation Centre in Stirling gives it away as a training facility for traditional building methods and materials. There may be a restored engine shed sandwiched in between, but these are very contemporary ‘pieces of bread’, mimicking the middle with eave-less minimalism. Peel away the VMZinc walls and roof, though, and you’ll find a timber-framed structure stuffed with sheep wool insulation. The Anthra-zinc is installed in artisanal ways too – standing seam, flat lock, composite – some of which hark back to 19th century Paris. But how, when they restored the shed’s slate roof, did they rub the grey onto the sky?