Diogo Aguiar Studio Strings Eight Identical Timber Modules Across a Hillside Above Porto

Hillside houses in northern Portugal usually follow a familiar plan: find the highest point, pour a platform, and point a wall of glass at the view. Diogo Aguiar Studio does something else with House Over the Hills, a 200 m² single-family home in Aguiar de Sousa, in the Serras do Porto. The studio sets out a chain of identical timber modules, each with its roof tilted a different way. Seen from the access path, the house reads less as one building and more as a small ridge of pitched planes picking up the outline of the mountains beyond.

Two things interest us here. The first is the architects' own claim that the house was not placed to command the best view, but where architecture and landscape could share the same ground. The second is the program. Five modules form a three-bedroom house. Three more stand independently with their own doors to the outside, holding two autonomous bedrooms and a multipurpose room that could later serve tourism. The prefabricated timber system is being used for more than speed of construction: it lets one repeated unit hold a household whose needs will change.

A Ridge Made from One Repeated Unit

From above, the logic is easy to read. Every volume shares the same geometry, but each one is rotated or stepped so its inclined roof faces a different direction. The metal roofs catch the low sun at different angles. As a result, a modular house that could have looked like a row of shipping containers reads as a broken, mountain-like profile among the pines.

We think this is a smart answer to a common problem with prefabrication. Repeating a unit is cheap and precise, but it tends to flatten character. Here the variety comes from how the units are arranged and how their roofs tilt, not from extra parts. The red window hoods are the only accent, and they work as small signals that a module holds something particular inside.

Sitting Low Instead of Commanding the View

The architects say they set the height at which the house meets the ground for two reasons: to frame the landscape from inside, and to keep the roofs visible from the path as you approach. In practice the house sits among the rocks and trees rather than above them. Under heavy cloud, the gabled timber faces with their vertical boards read almost as part of the woodland. In low golden light, the zinc planes become the stronger presence.

The existing trees were treated as part of the design, and you can see it. The pines are not cleared to open a panorama. They stay in front of the house, overhead, and between the modules, so the house works within the landscape rather than presenting it as a picture.

Thresholds, Corners and the Edge of the Deck

The openings are where the architecture is most precise. Glazed corner doors cut into the timber cubes, and a weathering steel frame turns one opening into a glowing box at dusk. Openings face different directions and sit at different heights, so each room gets its own particular view rather than a share of one big one. Young pomegranate and cypress saplings on the slate gravel suggest that the planting will grow along with the house.

The independent modules make the outside part of the circulation. A wooden deck along a timber wall, under a rust-colored awning, works as both a terrace and a corridor. Inside, a floor-to-ceiling glazed wall with a linen curtain looks across to the next timber volume. Neighbouring modules frame each other's views, which is a modest but effective way of giving a dispersed house a sense of togetherness.

A Pine-Lined Interior Built Like Furniture

Inside, the timber construction is not hidden. Pine boards line the walls, the wide planks run along the floor, and plywood shelving and built-in sideboards fill the corridors. The dining room, with its long wooden table and sliding glass door facing a stone wall, feels close to cabinetwork. The palette is narrow on purpose, and it holds the series of small rooms together.

The bathroom shows how far the approach is taken. It is a narrow room lined in knotty pine, with a white mosaic floor and a round mirror, and nothing in it pretends to be bigger than it is. The modular dimensions set the limits, and the architects work within them instead of trying to disguise them.

Bedrooms Under the Pitches

The roof geometry that gives the exterior its profile also shapes each bedroom. Sloped ceilings, some in pine and some painted white, give every room a different section. A narrow loft with a low sleeping platform and a vertical slat balustrade makes use of the tallest part of one module. Pendant lamps and sheer curtains keep these rooms calm and slightly enclosed, which suits a brief that asked for a quiet life close to the city.

Pivot doors and pine-faced leaves make the move from corridor to bedroom feel deliberate. That matters more here than in a typical house. Some of these rooms may one day be rented, lived in by grown children, or used by guests through their own outside doors, so each module has to work as a complete room on its own.

Plans and Drawings

The site plan shows how small the zigzag footprint is among the scattered houses and roads of the hills. The floor plan explains how the staggered chain works: a central corridor ties the five core modules together, while decks and outdoor paths reach the independent units. The elevations and sections show the alternating monopitch roofs that create the ridge-like silhouette.

The wall section and axonometric are the most useful drawings for understanding the climate strategy. A lightweight timber frame-and-panel structure sits over a concrete base. The concrete gives thermal mass against the ground, and a ventilated air cavity below the house helps with comfort. With the house facing southwest, the result pairs light, quick prefabrication above with heavy, stable thermal mass below. The exposed-frame axonometric makes clear how little material the repeated module needs.

Why This Project Matters

Portuguese domestic architecture is often discussed through concrete and stone, so it is notable that a modular timber house won the 2025 National Prize for Timber Architecture (PNAM '25). Diogo Aguiar Studio shows that prefabrication does not have to mean sameness. Rotating one unit and varying its roof slope produces a house with real character, and it does so with a structural system engineered by PENREA and built by Grupo Grandys, Somaia.

The bigger lesson is about time. Most single-family houses are designed for the household that commissions them. This one plans for change from the start, with modules that can be bedrooms, a studio, or rental rooms, each with its own door. Combine that with a placement that respects the trees and a low position on the slope, and you have a model for building in the hills around Porto that is lighter on the land and more adaptable over the years.

House Over the Hills by Diogo Aguiar Studio, Aguiar de Sousa, Portugal. Area: 200 m². Completed: 2023. Photography: Fernando Guerra | FG+SG.

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