No. 18-20 Lancaster Grove in Belsize Park was built c.1930 and is situated in a Conservation Area of predominantly later Victorian housing with some Edwardian pockets. The design of the original structure was not of particular architectural merit, and was generally of inferior quality in terms of construction and detailing to other buildings in the Conservation Area.

George Saumarez Smith was commissioned to draw up a proposal for a replacement building which responds to the established character of the area and provides a new, refined, high quality classical house in the spirit of Regency-influenced Arts and Crafts architecture.

The house will be constructed using natural lime render and slate, allowing it to harmonise with the palette of materials used in the vicinity. The simple continuous geometry of the roof is particularly characteristic of the Arts & Crafts-trained architects designing in a more classical mood. The north façade facing the street is a simple, balanced design featuring a semi octagonal stone bay and fanlight spanning two floors, between two slightly projecting pavilions. This central feature allows for a light and spacious central hall area with a central vista running through the entrance to the dining room and out past a veranda onto the gardens.

The rear elevation has a colonnade with a balustraded balcony above, facing south onto the garden. Stone window surrounds are used on the east projecting wing, whilst on the west, a bay steps forward to address the main entrance through the existing gate piers. The proposal also features a panel of specially designed decorative scrollwork, which provides an exciting opportunity to add to the local tradition of decorative enrichment. The proposal has now been granted planning permission.