A French fashion designer known for her bohemian aesthetic, Isabel Marant, will open her first Manhattan showroom in a space resembling a retail store in the Chelsea Arts Building at 210 Eleventh Ave.
The 4,070-square-foot showroom on the 25th Street side of the building has large windows and polished concrete floors. Its private entrance will make it easier for such celebs as Kate Moss, Sienna Miller and Kate Bosworth to dash in for a special item…