Aires Mateus and MA+Co Rebuild the Australian Beach Shack in Board-Formed Concrete at Mount Martha

The Australian beach shack is a fragile thing by design: a lightweight timber box, cheap enough to lose and loose enough to sprawl. Mori House, completed in 2023 in Mount Martha on Victoria's Mornington Peninsula, keeps the shack's informal habits and discards its fragility entirely. Aires Mateus, working with Melbourne practice MA+Co, has cast a 365 m² house for a multigenerational family almost entirely in board-formed concrete, set among established tea trees that look over Port Phillip Bay. Jeff Provan, founder of the Melbourne developer Neometro, built it.

What interests us is less the material than the way the plan uses absence. A series of voids splits the house into four distinct areas, so the building reads as a cluster rather than a single object, and the gaps between the parts do as much work as the rooms. The name means "forest" in Japanese, and the project openly mixes Australian, Japanese and Portuguese references. That could easily turn into a pastiche of collected moods. Here the mix mostly holds because the concrete is strict enough to carry it.

A Shack Recast as Something Permanent

Seen from outside, the house gives away very little. Walls marked by their formwork rise straight out of gravel and grass. Windows sit deep in the mass, and a slatted pergola on the roof is the only sign that the building expects anyone to linger up there. The board marks matter, because they keep a trace of timber on a surface that otherwise has nothing in common with a weatherboard shack.

The woodpile stacked beneath the roof terrace says more about the brief than any statement of intent. This is a house built for long family summers, for fires and for staying put, and the architects have treated permanence as the most generous thing they could offer a family that plans to return for generations.

Courts Carved Between the Walls

The voids that divide the plan become gravel courts planted with olive trees, and this is where the Portuguese side of the project shows most clearly. These are outdoor rooms with walls on several sides, a concrete table and a pivot door that opens the interior directly onto them. They are closer to a Mediterranean patio than a suburban deck.

At dusk the courts become the main event. Light from inside spills across the gravel, and the curved, slightly leaning concrete walls take on a softness they lack at midday. The courts also give each part of the house a degree of independence, which suits a family that spans several ages and routines.

Stairs, Screens and Cantilevered Edges

Most of the detailing happens at the edges. A granite stair with a slim steel handrail climbs between the concrete walls toward the roof, under a cantilevered slab that frames it like a porch. A timber bench sits at its foot. Vertical timber screens slot into the concrete, and a thin metal balustrade runs along the top of the walls, light enough to disappear against the sky.

The contrast is deliberate and well judged. Heavy surfaces carry the architecture, while timber and steel handle everything that touches the body: rails, benches, doors and screens. A glowing timber-lined doorway beside the stair at dusk sums up the approach, a warm interior held inside a hard shell.

Pavilions Under the Tea Trees and Eucalypts

Taken as separate pavilions, the house sits more comfortably on its site than one large concrete mass could. Deep overhangs and glazed corners open the volumes toward fruit trees, lawn and tall eucalypts, and the canopy keeps the scale of the buildings in check. The glazed dining pavilion facing the lawn is the most open moment in the scheme, shaded by a camouflage-net canopy that looks improvised in the best beach-house tradition.

That net is a small but telling choice. It sets a cheap, temporary layer against the permanent structure and lets the family adjust shade without changing the architecture. Paper lanterns and leafy branches against board-marked walls carry the same idea at a smaller scale: soft things are allowed to come and go.

Living Around Fire and Light

Inside, the concrete stays exposed on ceilings and walls, and the living spaces gather around fire. A triangular concrete hood hangs over the fireplace in one room, and a black stove sits beside a timber-clad core in another. Orange curved sofas, cowhide and sheer curtains warm up surfaces that would otherwise feel austere.

The best moment is overhead. Skylight slots cross the concrete ceiling above one seating area, so daylight falls in narrow bands rather than through a conventional opening. It is a characteristically Aires Mateus gesture: light treated as something cut out of mass, and it gives the heavy roof a sense of lift.

A Steel and Marble Kitchen

The kitchen leans furthest away from the shack. Brushed steel cabinetry with flush doors, a stainless island and a marble top line a long board-marked wall, with framed artworks propped on a shelf above. Paper globe pendants hang low, and tree shadows move across sheer curtains.

It works because the palette is so narrow. Steel, stone and concrete share a cool tone, and the curtains and lanterns supply the warmth. The kitchen reads as part of the structure rather than as fitted furniture, which suits a family space that has to absorb a lot of daily use.

Passages That Feel Like Places

Circulation here is not left over. A concrete hallway holds a stove flue, a large rose painting and a folded paper lantern at its far end. Elsewhere a curved board-marked wall carries a carved wooden figure on a plinth, lit by a single blade of sunlight across the floor. The slight curvature of the walls, which you barely register from outside, becomes legible in these corridors, where light grazes the surface and picks out every board line.

Tatami, Bunks and Bathing

The sleeping spaces show most clearly how the brief accommodates several generations. There are conventional bedrooms, but also a tatami room with shoji screens and a low red table, and a bunkroom lined in vertical timber boards with built-in beds and a leaning ladder. Each suggests a different way of sleeping over, from the formal guest to the grandchild who wants a top bunk.

Timber dominates in these rooms, and that is the right call. It wraps the most intimate spaces while the concrete ceiling stays visible above, so you never lose the sense of the larger structure. The bathrooms continue the tone with marble tile, round mirrors, wall-mounted basins and a mushroom-shaped stone stool, all approached through timber-clad passages.

Plans and Drawings

The site plan shows how the scheme is put together. A long central spine links separate rectangular pavilions, with a triangular garage and a pool loosely placed among the existing trees. Read alongside the view of a pavilion beneath the eucalypts, the drawing makes it clear that the trees set the gaps and the buildings were arranged around them.

Why This Project Matters

Coastal houses in Australia often swing between two poles: the nostalgic lightweight shack and the glazed luxury box. Mori House takes a third route. It keeps the shack's sociability, its outdoor rooms, its bunkroom and its makeshift shade, and gives them a structure meant to last much longer than a summer house usually does. For a multigenerational family, that permanence is a functional decision, and the architecture treats it that way.

The cross-cultural layering is the riskier part, and it does not always resist styling. Still, the discipline of the plan, four parts separated by voids under a canopy of trees, gives the Japanese and Portuguese references something solid to sit on. The lesson for anyone designing in a landscape like this is that the gaps deserve as much attention as the rooms.

Mori House by Aires Mateus and MA+Co, Mount Martha, Victoria, Australia. Area: 365 m². Completed: 2023. Photography: Brook James.

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