Casa da Azenha Grows From a Ruined Watermill Near Lisbon

A ruined watermill in Arruda dos Vinhos, just north of Lisbon, now carries a complete private house within its original footprint. Casa da Azenha, designed by (Umtodo) architects, keeps only fragments of the mill's thick exterior wall and an internal retaining wall, which the studio retained to delineate the shift between the three levels of the new house.

The project demonstrates how little of a ruin a practitioner needs to keep in order to preserve a sense of place. All the original openings in the mill survive, and the architects used them as the basis for the internal plan, doors and windows of the new house.

'The project seeks to enhance both the existing fabric and its natural setting, reinforcing the dialogue between architecture and landscape,' the architects said.

How does the house organise its three levels?

Entry occurs at road level, which was originally the upper floor of the mill building as it steps down towards the riverbed. This level contains the main reception room, which soars into the void of the pitched roof around a central fireplace. Stairs lead up to the kitchen and dining area, alongside a guest bathroom. The dining area features a large frameless picture window with views across the valley.

An additional level sits directly beneath the kitchen and houses two bedrooms and a second bathroom. The building sits practically into the hillside, giving these lower rooms a monastic, cell-like feel that contrasts sharply with the light-filled upper floors.

What does the material contrast achieve?

The new structure features rendered grey walls set against the honey stone of the ruin. The architects framed this as a deliberate strategy rather than a default finish.

'To emphasise the contrast between the permanence of the historic ruin and the new intervention, the inserted building is conceived as a single, monolithic volume which recalls the archetypal form of a pitched-roof house,' the architects explained.

The monolithic insert reads as a child's drawing of a house nested inside the fragmentary shell of an industrial one. That double image is the project's core argument: reuse does not require mimicry, only a clear edge between old and new.

Who is behind the project?

The studio, led by João Pedro Cavaco with Hélia Pereira and Rafael Jaleco, is based locally and specialises in refined residential projects that maintain a calm, reflective relationship with the surrounding landscape. Casa da Azenha sits squarely in that practice: the house retains the memory of the watermill without compromising the demands of contemporary living, in the studio's framing.

For practitioners weighing adaptive reuse on tight footprints, the project shows a workable equation: preserve the openings, keep one structural wall that does organisational work, and let a single contrasting volume carry the new programme. The ruin supplies the identity; the insert supplies the plan.