This project involved adding two new storeys and habitable attic space to an existing building, raising it from ground floor plus one level (R+1) to ground floor plus three levels (R+3) plus converted lofts, while keeping the building occupied throughout the works. The main challenge was to increase the site density without disturbing the balance of the street: the new height, proportions and slate roof naturally extend the neighbouring building profile to create a homogeneous whole, with no visible break between old and new volumes.

The intervention follows a strong environmental approach. The vertical extension is built with a timber structure, complemented by wood‑fibre insulation and a cream‑tinted lime render, which improves thermal comfort while respecting the character of the original building. This high‑performance envelope upgrades the property and gives it a subtle, light‑filled and durable architectural expression.

​Inside, a new shared staircase with a skylight brings generous natural light into the heart of the building and turns the circulation area into a genuine living space. Four additional dwellings have been created, two per floor, of F2 and F3 types, with attic apartments on the top level. The dual‑aspect layouts offer living areas facing the street, bathed in light, and night‑time spaces on the courtyard side, ensuring calm and privacy.

​The project illustrates how rooftop extensions can preserve a building’s identity while delivering high‑quality densification: discreet yet efficient architecture, seamlessly integrated into its immediate context and carefully tailored to residents’ comfort.