There was a point at which sustainability looked like it might change the face of architecture. And more particularly its rooflines. Stroll along Manchester’s Oxford Road and you cannot fail to notice the exuberant and excessive chimneyscape of the Contact Theatre, Alan Short’s demonstration of natural ventilation applied to the revamped sixties theatre (completed in 1999). From Feilden Clegg Bradley’s jaunty solar chimneys for the BRE in Garston (1996) to the formal bronze affairs at Portcullis House (2001) the chimney looked prevalent enough to trigger a counter movement of architects promising clients that chimneys weren’t essential for a sustainable building. We have in fact learnt how to turn whole buildings into chimneys, the science and modelling behind it ensuring that atria, as at the Siemens headquarters in Masdar City, and voids, as at the centre of Manchester Central Library, perform as strongly as they need to for cool, conditioning free natural ventilation. The Venturi effect of funnelling air has proved more significant to the body and innards of architecture than more recent, and celebrated, Venturi theorising about Las Vegas and ducks. Now practices can resist bolt-on green bling technologies – but only if they go beyond fabric first to build the basics into their designs.