A cache of leading firms contributed to the restoration and expansion of this modernist Richard Neutra manse – now on the market for $15m.

Neutra built Sten-Frenke House in 1934 for Ukrainian actress Anna Sten and her husband, producer Dr Eugene Frenke, in his breezy Californian Modernist style. The boxy Santa Monica property has a flat roof, signature ribbons of glass and ocean-facing terraces off its upper level.

It has undergone two major renovations in the last 85 years, one helmed by Marmol Radziner, and one by Mark Haddawy. But the house very much celebrates its midcentury modern heritage: rooms feature wood panelling (some of which has been replaced due to tobacco staining), built-in cabinetry, a brick fireplace and period furnishings.

Neutra’s dining room inspired the house’s most recent addition: practice Johnston Marklee added a two-bedroom guesthouse opposite the main home. Its curving facade borrows from the dining space and draws on elements of Streamline Moderne design.

Following its expansion – which includes the addition of a sauna and yoga room –  the Californian property is being marketed via Billy Rose of The Agency.

Pierre Koenig’s experimental Squire House is for sale in California