In the back half, the spa is defined by light materials and soft forms, beneath a series of half arches that lead to the common room with polished concrete floors and a blush pink centerpiece, Verner Panton’s 1969 Verpan Cloverleaf Sofa. Indirect lighting in the form of bright LED strips offset from polycarbonate-paneled walls allow the subterranean space to appear as if filled with natural light. Beyond the common room are six separate spa rooms with walls and doors of Baltic birch plywood, cedar flooring, a private steam shower, infra-red sauna and soaking tub, for the ultimate post-work relaxation.