Upper Terrace Lodge, as the terraced houses of which number four is a part were originally known was built c.1740. A new extension was built in the 1920s extending from the back of the Georgian house towards the edge of Hampstead Heath. It appears from the name on the drawings that the architects for the extension were Pine, Coffin, Imrie and Angell Architects of 2 Mitre Court Chambers, Temple, not Sir Edwin Lutyens as previously thought.
In the 1950s permission was granted to divide Upper Terrace Lodge into three single dwelling houses. It was at this time when the house was divided that the original curved Georgian staircase was removed and replaced with a smaller one to serve the ‘cottage’ while the stair in the ‘Back Hall’ of the 1920’s extension became the main house stair. This left a confused and ill-figured staircase arrangement for no. 4.
The alterations that Theis and Khan undertook included re-siting the main staircase void in order to reunite all the rooms on each floor and create a new focus for the house. The design was based on woven willow fencing, a reference to Hampstead Heath. The other main move was the opening up of the rear kitchen area to create one large open kitchen and living room with a glazed roof over. The remainder of the house refurbishment involved the re-planning of bedrooms and bathrooms and the provision of a cinema in the basement.