PHD Architectes Lifts 47 Apartments Above the Oaks in Saint-Herblain's Bagatelle Park

Saint-Herblain sits just west of Nantes, and for decades its northern districts were defined by Le Sillon, a monolithic 900-unit housing block dating to the 1960s. Renewal operations around that complex triggered a larger ambition: Bagatelle Park, a 20-hectare zone planned for 1,100 new dwellings intended to stitch the isolated quarter back into the city. The Bash Residence by PHD Architectes occupies Lot E of that plan, a 4,100-square-metre parcel wedged between a school and a primary road, and it treats the site's existing oak canopy not as an obstacle to density but as the organizing principle for it.

What makes the project worth studying is the discipline of that single move. Three compact volumes are raised on a semi-buried parking plinth so their footprints dodge the root zones of mature trees. The result is a ground plane that reads as continuous landscape rather than leftover space between buildings. Concrete balcony slabs and perforated metal screens give the facades a taut, layered quality that shifts register depending on whether you read them through foliage or from the street. It is housing that earns its place by ceding territory to the site.

Three Volumes, One Canopy

Forty-seven units are split across three freestanding structures that read as fragments of a single composition. The buildings are oriented and spaced to preserve the tallest oaks on the parcel, so the canopy, rather than the architecture, dominates first impressions. Gray-tinted concrete cladding recedes against the trunk tones while allowing the perforated metal balustrades to catch light through the leaves. The architects have calibrated material warmth against visual restraint: neutral enough to disappear into the green, specific enough to hold your eye when the trees are bare.

The Balcony as Mediating Device

The most assertive detail across all three buildings is the balcony system. Cantilevered concrete slabs project from the facade, their edges lined with perforated metal screens and, in places, white tension cables that act as diagonal bracing. The screens serve a triple purpose: solar shading, privacy filtration, and visual continuity. Because the perforation pattern is consistent from unit to unit, the facades read as a single woven surface rather than a patchwork of individual terraces.

Tension cables add structural stiffness to the cantilevers while introducing a slender, almost nautical line to an otherwise heavy concrete palette. That contrast between mass and filament keeps the elevations from feeling monotonous. When afternoon sun passes through the perforated panels, the pattern throws dappled shadows across the slab edges, doubling the effect of the tree canopy just beyond.

Interior Threshold

From inside the apartments, the perforated screens register differently. Sliding glass doors open flush onto the balconies, and the metal panels filter daylight into a soft, even wash that keeps interiors from overheating while maintaining views of the surrounding trees. The transition from living room to balcony to canopy is almost seamless: three layers of filtered light that compress the boundary between domestic space and landscape.

The photographs of the corner units are telling. Morning light enters on two sides, and the perforated railing casts a fine grid of shadow across the floor slab. There is nothing elaborate about the finishes, no signature material palette beyond white walls and concrete thresholds. The luxury, such as it is, comes from proximity to the oaks and from the calibrated depth of the balcony zone, deep enough to furnish, shallow enough to stay bright.

Ground Strategy: Lifting and Burying

Parking is the unglamorous problem that derails most mid-density housing projects. Here, the cars are tucked into a semi-buried plinth enclosed by a light metal mesh that allows natural ventilation and eliminates the dead wall effect of a conventional garage podium. A green roof caps the plinth, extending the landscape plane and giving ground-floor residents something to look at other than asphalt. Because the residential volumes sit on top of this plinth, their ground floors are elevated just enough to grant a sense of separation from the public path network without requiring an imposing stair or ramp.

The decision to bury rather than surface the parking also freed up plan area at grade for planting. In a district designed around 1,100 new units, that recovered green space compounds across lots. If every parcel followed the same logic, Bagatelle Park could mature into something closer to an inhabited forest than a conventional housing estate.

Plans and Drawings

The aerial site plan confirms what the photographs suggest: the three buildings are not rectilinear bars but slightly undulating forms that follow the irregular spacing of the trees. Their roof outlines curve gently, opening gaps where the largest oaks stand and pinching closer where the canopy thins. The drawing also shows how the parcel's western edge runs along a street while its eastern boundary merges into the deeper woodland of Bagatelle Park, a gradient from urban frontage to forest that the architecture mirrors in its decreasing formality from entrance side to garden side.

Why This Project Matters

Mid-density housing in French renewal zones often defaults to one of two modes: nostalgic contextualism that mimics surrounding fabric, or glossy signature blocks that ignore it. The Bash Residence charts a third path by treating the landscape itself as context. PHD Architectes accepted the constraints of existing trees, a semi-buried parking mandate, and a tight parcel boundary, and turned those constraints into an organizational system. The result is housing that feels inevitable on its site rather than imposed upon it.

For the broader Bagatelle Park masterplan, the project sets a useful precedent. It demonstrates that sustainable densification does not require heroic engineering or exotic materials. Concrete, steel, perforated metal, and a disciplined attitude toward what already grows on the ground can produce architecture that ages well, shades itself, and gives residents a reason to open their doors in the morning. That is a low bar, perhaps, but one that a surprising number of urban renewal projects fail to clear.

Bash Residence, designed by PHD Architectes. Saint-Herblain, France, 2023. 47 residential units across a 4,100 m² site within Bagatelle Park. Photography by Julien Hourcade.

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