The long, slow escalator ride up the side of Renzo Piano's Broad Contemporary Art Museum inevitably recalls the ascent up the architect's most remarkable building, the Centre Pompidou in Paris, designed with Richard Rogers and opened exactly three decades ago. But instead of a radical view from inside a machine for art over the romantic rooftops of Paris and the Eiffel Tower beneath glowering grey skies, the ride up Piano's new building takes in the anti-urban sprawl of Los Angeles, a ragged panorama of second-rate skyscrapers, strip malls, snaking freeways and the Hollywood Hills against the sparkling sunshine and deep blue sky of Southern California.

Apart from that ascending exoskeleton, the two buildings have absolutely nothing in common. The Pompidou was a radical insertion into the heart of ultra-conservative Paris, a garish building that finally realised 1960s fantasies of flexible fun palaces, the gallery as public realm, the city as a machine for culture. The Broad Contemporary Art Museum (BCAM) in Los Angeles is a tasteful, conservative stone-clad monument to the power of the super-rich collector.