Designed by Francesco Pierazzi Architects, Sawtooth House renovates and extends a Victorian home in Kingston upon Thames through a contemporary rear addition informed by the area’s industrial history. Replacing an outdated extension, the project introduces a distinctive double sawtooth roof that references the profile of nearby manufacturing buildings, including Middle Mill, formerly home to The Patent Cocoa Fibre Co. Ltd. Although the intervention adds only 15 sqm of floor area, it reorganizes the home’s spatial layout while improving its environmental performance.

The extension is conceived as an alternative to simply increasing floor space, using light, materiality, and spatial organization to redefine the relationship between the existing house and the garden. New brick volumes respond to Kingston’s industrial character through varied brick bonds and textured facades, establishing a dialogue between the Victorian structure and the contemporary addition. Hidden from the street, the extension maintains the scale of the surrounding neighborhood while opening into a series of light-filled interior spaces.

all images by Peter Molloy

The double sawtooth roof shapes the character of the new living spaces, bringing daylight deep into the plan through rooflights while creating angled ceilings that define individual areas within the extension. Carefully framed views connect the interior with the garden, while a palette of soft pastel tones, oak joinery, and terrazzo surfaces introduces color and texture throughout the house.

The renovation by studio Francesco Pierazzi Architects was developed in close alignment with the clients’ environmental objectives. Alongside the new extension, the existing Victorian house underwent a comprehensive retrofit designed to reduce operational energy demand and improve long-term building performance.

The retrofit includes extensive insulation upgrades, an air source heat pump, and a mechanical ventilation system with heat recovery to improve thermal performance and indoor comfort throughout the year. A 7,500-liter underground rainwater harvesting tank supplies water for garden irrigation, reducing reliance on the municipal water network. Together, these measures reduce operational carbon emissions while allowing the embodied carbon associated with the renovation to be offset through operational savings in less than seven years.

Sawtooth House examines how targeted architectural interventions can extend the life of existing housing while responding to contemporary environmental requirements. Through references to Kingston upon Thames’ industrial heritage, a restrained material palette, and an integrated retrofit strategy, the project combines adaptive reuse with improved spatial and environmental performance.