A lavish terraced property, No. 22 Grosvenor Gardens has been transformed from its previous use as a sixth-form college to a high-specification modern workspace with restored period features.

The building, in the Grosvenor Gardens Conservation Area of the City of Westminster, forms part of a grand Victorian era terrace developed from elevations by Grosvenor Estates Architect Thomas Cundy III in the 1860s and using an individual plot width of 7.8m (25.6ft) by approximately 31.7m (104ft) deep. The accommodation was originally spread across the ground and four upper floors, with generous subservient attic and basement spaces which had previously been adapted for use.

As a result of frequent alteration and changes of use, many of the building’s original features had been lost, leading building owners Grosvenor Estates Belgravia to commission Bennetts Associates to redevelop the property, creating a benchmark for quality in the neighbouring terraces.

The comprehensive refurbishment and extension provides 6,500 sq. ft. of B1 commercial workspace spread over six floors. In a first for a Grosvenor Estate commercial property, the thermal efficiency of the 150-year-old building fabric has been dramatically improved - reducing airtightness to 8m3/hr-m2 and annual carbon expenditure to 24,409 kgCO2/m2yr which represents a 42% saving. This exemplary standard has been achieved through a delicate balance between reinstated architectural features and a new contemporary rear extension to create a sustainable, high quality commercial office.