Set on a narrow six-metre plot in Kifisia, aTREEum House is organised around an existing tree preserved at its centre. A timber structure of Cross-Laminated Timber and glulam, combined with passive design, a rooftop greenhouse and rainwater harvesting, defines an architecture that integrates urban biodiversity and operates at near-zero energy.
aTREEum House is a contemporary timber residence in Kifisia, designed for a narrow six-metre-wide plot in one of Athens’ most established residential districts. The design begins with the preservation of an existing mature tree at the centre of the plot; the floor plan opens around it, turning the tree into the home’s organising element rather than treating it as a constraint to work around. As a timber residence in Kifisia, this project demonstrates how a constrained urban site can host a building that contributes biodiversity to its neighbourhood instead of removing it.
The building is the first timber structure in the area, built with Cross-Laminated Timber (CLT) panels for the walls and floors and glulam for the structural beams. This construction choice substantially reduces the embodied carbon of the project compared with a conventional reinforced concrete equivalent, and it supports a faster, lighter and quieter construction process. The timber is exposed internally where possible, contributing to a warm, calm interior atmosphere consistent with the architectural intention of a timber residence in Kifisia.
A central atrium preserves the existing tree at the heart of the home and acts as the building’s passive climate engine — drawing daylight deep into the plan, providing stack ventilation, and tempering interior temperatures across the seasons. A rooftop greenhouse functions as thermal storage and edible garden. Rainwater harvesting supplies irrigation, and a system of perforated steel shading — fabricated from scrap material at a local CNC workshop — modulates summer sun across the south and west elevations. Together these strategies allow the house to operate at near-zero energy demand, demonstrating how a contemporary timber residence in Kifisia can integrate biodiversity into the everyday experience of urban Athens.
aTREEum House has been recognised in international architecture distinctions including the Architizer A+ Awards. The project is part of ONUS’s award-winning sustainable architecture and one of several contemporary timber and passive residences in Greece.
