The Swiss architect Peter Zumthor and the director and chief executive of the Los Angeles County Museum of Art (Lacma), Michael Govan, have unveiled bold new designs for the museum’s future $600m extension. Speaking at the museum on 5 April, they presented renderings that reveal significant changes to Zumthor’s vision for the elevated 368,000 sq. ft wing, which will span the city’s Wilshire Boulevard. The architect has replaced his organic “black flower” form, inspired by the art of Jean Arp and the nearby La Brea tar pits, with a harder-edged design in sand-coloured concrete. The building’s outer walls will now match the interior to achieve an “elemental” effect, Zumthor says. “If I’m lucky, the building will be like some kind of an Inca temple,” he told the Los Angeles Times.