Behind the Georgian facade of a historic London property, architecture office Cullinan Studio has overhauled living spaces to create an oak-framed family room that opens out to the garden (+ movie).

House in Hampstead is a Grade-II listed end terrace in a row of Georgian residences, but has undergone many alterations over the years that have complicated its layout. London-based Cullinan Studio was tasked with transforming the building back into a well-planned family home.

"Much of the original integrity had been lost through a series of clumsy interventions. The house was poorly planned – with no real central living space or easy flow from one part to another," said the design team.

"We did not want to simply add on more living space but rather improve the upper and lower ground floors of the house in a way that worked with the existing building, both internally and externally."

The main intervention was the creation of a generous square living space, nicknamed "the cube". This south-facing room extends beyond the original fabric of the building, and features floor-to-ceiling glazing that connects it with the garden.

This room is framed by a combination of steel and timber that create a clear distinction between the new and old parts of the structure. To complement this, the internal materials palette includes birch plywood and oak, alongside white-painted walls.

"Extensions to similar houses close by had aimed for a contrast to the existing style. We took a different approach and started with what was already there," explained the team, whose past projects include a storage facility for the British Film Institute.

"We chose materials that were the same or similar to the original house: timber; glass; neutral-coloured fenestration; and off-white coloured rendered masonry panels."

Bookshelves have been built into most of the non-glazed walls that surround the living space. In between these, doorways lead through to a series of smaller rooms and spaces that include a study, a snug and a kitchen and breakfast space.

A wooden staircase leading up to the floor above is located in one corner of the living room. There is no handrail, but a row of vertical wooden posts create a tactile surface around the adjacent wall.

"We worked closely with craftsmen to ensure an immaculate finish," added Cullinan Studio.

There are also clerestory windows set back from the walls, to bring light right through the space.

Externally, the roof of the extension is covered with sedum to create a pleasant outlook for neighbours, but there's also a small balcony terrace.

House in Hampstead is the latest in a series of modern residences to complete in the leafy London borough. Stanton Williams recently completed a new house nearby, while Duggan Morris received the Manser Medal for its sensitive adaption of a 1960s residence.

Photography and movie are by Paul Raftery.

Project credits:

Architect: Cullinan Studio
Project director: Carol Costello
Project architect: Kevin Goh
Structural engineer: Cullinan Studio (John Romer)
Main contractor: Cape Construction
Services engineer: Synergy Consulting