At Ljubljana Castle, three wooden rooms stack into a slender tower, their angular ends pointing toward the city. This built installation from 2017 demonstrates Living Unit, a modular architecture system developed by OFIS Arhitekti with C+C, C28, structural engineers AKT II, and contractor Permiz. The idea begins with a small, repeatable wooden shell.
Each basic module measures 4.5 meters long, 2.5 meters wide, and 2.7 meters high, roughly 14.8 by 8.2 by 8.9 feet. Designed to accommodate two people, it can hold a double bed, wardrobe, table, and chairs, with provision for a bathroom and kitchenette. Those are compact cabin dimensions, rather than the proportions of a conventional apartment.
Designer: OFIS Arhitekti
The useful move is allowing that initial room to become part of something larger. Modules can connect horizontally or vertically, with combinations intended to accommodate four to six occupants. A single cabin might suit a short stay; several connected shells allow the domestic functions to spread out. The system therefore offers different arrangements without requiring an entirely different building vocabulary.
Its pointed geometry gives the project much of its character. The ends taper into truncated pyramids, with glazing at their tips. AKT II explains that these projecting forms add internal storage space while expressing the structure’s strength. Seen from outside, the alternating projections make the stacked version read as individual rooms, rather than one uninterrupted shaft.
Behind that silhouette is a prefabricated timber frame reinforced with plywood boards on both sides. The architects allow the exterior and interior finishes to change according to context. That distinction matters: the repeated element is the structural shell, not a compulsory decorative package. Different settings need not receive an identical-looking cabin simply because they share its underlying construction.
Ground connections are similarly adaptable. The units can be secured using steel anchors or removable concrete cubes instead of permanent foundations. The team proposes uses including holiday cabins, research accommodation, tourism, and shelter. These are intended applications, though, rather than proof that one specification will perform equally well across every climate and terrain.
The castle installation gives the system another role: a temporary library, with books organized across its levels and nearby outdoor areas intended for reading. It’s a useful demonstration of how the same shell can support a public program rather than accommodation. Here, the architecture supplies a small vertical destination within an existing landscape.
The sectional drawings also expose the compromise behind the tower’s small footprint. Compact steps and ladders connect its levels, making circulation an active part of occupying the stack. Horizontal expansion would avoid that particular arrangement but require more ground. Living Unit’s strongest proposition is this choice: repeat the room, then decide where the extra space should go.
