The main façade gently curves, focusing like a radio telescope on the only architectural point of distinction in the surrounding townscape, the masterly early 18th century church of St. Paul by Thomas Archer. Once through the Laban's facade, there's a surprise: first thing you encounter is a black concrete spiral staircase, beyond which is the expansive sloping floor of the lobby, also in black. Herzog and de Meuron are fond of black (check out the Stygian public spaces at Tate Modern). Here, where the staircase and balustrade concrete is left deliberately rough before painting, it glitters as if hewn out of solid coal, balanced by Craig-Martin's fresh colours (and giant-scale murals) elsewhere. This artist-architect collaboration was helped by a grant from the RSA Art for Architecture programme.

There are lots of big tall studios, a fine café, wide open spaces for students to mill around it, some unexpected intersections within the building, as when you catch a glimpse of an upper courtyard dropping like a wedge of cheese into the main foyer, acting as an inverted lantern. I like the slender swooping timber handrails everywhere. But the main surprise is the 300-seat theatre at the building's heart. You're not visually prepared for this, because from the outside the building carefully conceals its stubby flytower behind shallow sloping roofs. The small auditorium - lined with blackened timber, naturally, with artfully bare tungsten light bulbs - faces an enormous dance stage behind a charmingly old-fashioned orange-gold curtain. Laban is assuming a more public role with this building, with seasons of ticketed dance and music events. Unlike the equivalent and wholly different new theatre by Bryan Avery within RADA, the premier actors' training school, the Laban's auditorium will be for performances by visiting companies as well as students.