Dartmouth Park House by Architecture for London

Location: 25 Dartmouth Park Hill, NW5 1HP, London, UK
Construction cost: £ £920K
Gross internal floor area: 370m2
Form of contract: JCT Intermediate
Architects: Architecture for London
Structural engineer: Michael Hadi Associates
Main contractor: Varbud Ltd
QS: Baker Mallett
Approved Inspector: Butler & Young Group Ltd
Photographer: Architecture for London

About Studio

Our aim is to improve people’s lives by reimagining the places in which we live and work. The studio is a collaborative team of architects, and landscape and interior designers. We work at all scales, from furniture to bespoke private homes and commercial developments. We are an RIBA Chartered Practice based in London.

Environmental impact is a key consideration in our work. We take a research-based, fabric-first approach to sustainability that carefully considers the embodied energy of materials and the performance of our buildings in use. Director and architect Ben Ridley is a Passivhaus designer.

This house extension and full refurbishment in the Dartmouth Park Conservation Area are designed to better connect the three-story Victorian property to its large, landscaped gardens. A new dining room with full-height glazing and oak framed sliding door leads to a landscaped terrace, and a separate ‘glass box’ evening room allows uninterrupted garden views, with a suspended wood-burning stove for cozy winter evenings. Between these two spaces, a sheltered outdoor kitchen is created with a built-in gas barbecue and hot plate.

Concrete beams at the ceiling level create a horizontal datum across the spaces. This begins internally and continues outside to shelter the barbecue area, finally returning to the ground to form a new pergola against the garden wall. When viewed from the garden, this continuous horizontal line creates the impression of a unified, wide extension that emphasizes the generous 17m garden width.

Portland Roach stone to the rear elevation features distinctive fossilized shell fragments. The calming color palette of pale stone, light-oiled oak, and white concrete complements the tones of the existing Victorian brickwork. The interior spaces are filled with light due to the southwest-facing aspect and full-height glazing and roof lights.

The internal refurbishments to the existing building include opening up the ground floor to create an open-plan kitchen that runs from the front to the back of the house, where it connects to the dining room extension. A new utility and plant room have also been created. The first floor was reconfigured to create a master suite, comprising an open-plan sleeping and dressing area with an en suite shower room.

The other half of this story has been modified to form a library and cinema room with surround sound. The house has been completely rewired, including a whole house audio-visual system, with integrated speakers in most rooms. The materials on the first floor vary from the floor below by using walnut timber finishes, basalt stone, and a darker shade of grey throughout, to create a more relaxed atmosphere.

The second floor was redesigned to allow for the introduction of an additional shower room. Loft and roof terrace access has been improved and the unattractive scaffold pole handrail was replaced with a frameless glass balustrade to make it more discreet when viewed from pavement level. The new terrace has been landscaped to allow for level access from the rear extension out onto the stone paving.

The rest of the garden has been simply and elegantly planted, the large lawn is punctuated with feature birch trees. The rear of the existing Victorian villa was covered by attractive ivy, which required removal due to brick damage. The proposed pergola’s beams will support local wisteria growth, allowing climbing plants to be reintroduced in a controlled fashion. This will create dappled shadows in the evening room that oscillate with the breeze.