Arches House: A Brick and Arch Extension to a West Hampstead Family Home
Arches House is a semi-detached family home in West Hampstead, North West London, reworked around a two-storey side and rear extension. Completed in 2023, the project reconfigured all three floors of the house and gave it a new garden elevation of brick and arched openings. The client came to us wanting something more permanent than the standard white rendered rear addition, and the design grew from that shared position.
Client: Private
Location: West Hampstead, London NW2
Local Authority: Barnet Council
Plot Type: Suburban
Project Type: Residential – Single Family Home
Internal Area (GIA): 344 sqm
The ground floor is organised around a single open kitchen, dining and living space at the rear. Large arched openings frame the garden and let the family move directly between inside and out. The arches do practical work as well as visual work: their deep reveals shade the glazing and give the openings a sense of thickness you rarely get in a modern extension.
The first and second floors were replanned at the same time. Circulation was tightened, daylight improved, and the bedrooms and bathrooms rearranged so the upper floors work as calmly as the ground floor. Nothing in the original layout was treated as fixed.
The two-storey wraparound extension replaces the usual single-storey rear box with something that reads as part of the house rather than an addition to it. The garden elevation is a single composition: brick walls, arched openings, and consistent proportions from ground to roof. The brickwork draws on London's masonry tradition and reinterprets it plainly, without pastiche.
A two-storey extension of this scale needed a careful case at Barnet Council. We worked through massing studies and negotiation to demonstrate that the volume sat comfortably against the neighbouring properties and the street. The consent shows that scale and context are not opposites: the quality of the massing and detailing is what justified the volume.
This was not a certified low-energy retrofit, but the refurbishment upgraded the building fabric throughout. Insulation was improved, high-performance glazing installed, and airtightness increased across the works. The result is measurably lower heat loss than the original building and a home that holds a stable, comfortable temperature through the year.
The palette is deliberately short: brick for weight and permanence, slim steel-framed glazing, natural timber, and stone surfaces. Each material was chosen to age well and to need little maintenance. The interiors are robust rather than precious, made for family life rather than photography.
Arches House shows what a suburban extension can be when the client and architect agree from the start that the work should last. If you're considering a similar project, we'd be glad to talk it through.
