Swiss architect Peter Zumthor has revised his much-discussed design for the new US$600m (€565.5m, £483.2m) home of the Los Angeles County Museum of Art (LACMA).

His initial vision for a black organically-shaped structure, inspired by the nearby La Brea tar pits, has changed to something harder-edged and a different colour – with light earthy tones now set to be used for the monolithic facade.

According to LA Times, Zumthor presented the new design alongside museum director Michael Govan last week, and highlighted the need for the building to be 'timeless, indigenous architecture as a counterpoint to the flashy, richly decorated Spanish Colonial Revival buildings that were going up all over the city in the 1920s.”

“It took me a while to sort of let go of the baby,” he told the newspaper’s Christopher Hawthorne. “But I think I’ve figured it out. I’m happy. It’s less slick and more substantial. Elemental. If I’m lucky the building will be like some kind of an Inca temple that’s always been in the sand and now they’ve excavated it — a really old piece that’s always been there.”

Despite the aesthetic changes, Zumthor’s proposed floorplan, developed in 2013, appears more or less unchanged. As before, eight, semi-transparent pavilions will support the main exhibition level – linked together as one undulating form – and feature access points to the surrounding gardens.

The LACMA design has been revised once before, in 2014, following criticisms by local groups that the original proposals would put the tar pits at risk. The final plan sees the museum straddling Wiltshire Boulevard instead of encroaching on the pits.

In a recent exclusive interview with CLAD, Zumthor described his approach to the project and said the models of the building in his studio better evoke his vision than the “conventional, commercial-looking renderings” previously released to showcase the design.

Explaining his design concept, he added: “I would like people to look at it and think that it is much older than the other buildings there; that it belongs more to the ancient earth than to the other LA buildings.

“The museum is not organised in timelines, periods or geographical regions. It’s organised like a forest with clearings inside, where we have free choice to go to this clearing, or to the next. I would like to allow an experience of art where people can go and look at the art without didactics, without premature explanations, and make their own experience.”

The construction of the building is expected to start in the second half of 2018, It will be completed in 2023 to coincide with the opening of the adjacent New Metro Purple Line subway.