As a custom office space provider, Knotel has more than 100 locations in New York, San Francisco, London, Berlin and Sao Paulo in Brazil. In December, Knotel expanded its New York City presence with four new office leases totaling 78,780 square feet. The largest lease inked was a 51,000-square-foot space at Rosen family’s 27 W. 23rd St., which encompasses the entire second and third floors of the building. Knotel was represented by Elie Reiss of Skylight Leasing and the landlord was represented by Danny Breiman of Olmstead.