Atelier 9.81 Threads a Fully Reversible Timber Campus into Lille's 1878 Palais Rameau

A building designed for flower shows, repurposed as a car salon, borrowed for circus acts, and once commandeered for the Miss France election does not lack for charisma. Palais Rameau, erected in 1878 on boulevard Vauban in Lille through the bequest of horticultural society president Charles Rameau, was classified as a Historic Monument in 2002, but classification alone does not guarantee a future. The question was whether anyone could insert a rigorous contemporary program into its ornate greenhouse shell without scarring it. Atelier 9.81 answered with something more radical than a careful restoration: a completely independent timber structure that can, in theory, be unbolted and lifted out, returning the palace to its 19th-century emptiness.

What makes the Palais Rameau project genuinely instructive, rather than merely respectful, is that reversibility is not a gesture here. It is the structural logic. The entire interior insertion, a two-level post-and-beam framework of glue-laminated poplar from forests within 120 km of the site, rests on a micropile grid beneath a 60 cm false floor. No anchor touches the historic envelope. Demountable CLT panels form floors and partitions. The result is a 3,950 m² campus for JUNIA engineering school organized around food systems research, from vertical farming labs to pedagogical kitchens, all housed inside a building whose domes and cast-iron trusses remain visually and structurally untouched.

A Greenhouse Reborn as a Village Square

Auguste Mourcou and Henri Contamine's original design married the industrial logic of a greenhouse with ornamental flourishes drawn from both regional brick vernacular and orientalist fantasy. The twin domed towers, the striped stone facade, and the vast clerestory nave all spoke to a late 19th-century faith in horticulture as civic spectacle. In the 146 years since, the building's flamboyance aged better than its utility. Its enormous, uninsulated volumes were expensive to heat and difficult to program.

Atelier 9.81's intervention treats the palace as a found envelope, not a monument to be frozen. JUNIA's 25-year emphyteutic lease from the City of Lille explicitly frames the transformation as temporary stewardship. The school occupies classrooms, workshops, labs, and a food-systems incubator while the rotunda at the rear returns to its greenhouse origins, replanted as a biodiversity refuge. The conceptual framework, described by the studio as "fork to fork," integrates agricultural production, food transformation, and consumption into a single campus loop.

The Independent Skeleton

Walk through the interior and you read two distinct structural languages at once. The original cast-iron columns and arched trusses, painted a muted sage green, hold up the roof and walls. Inside that cage, a warm poplar framework carries its own floors, stairs, and partitions without leaning on the historic fabric. The gap between old and new is legible everywhere: at the mezzanine edge where timber balusters stop short of iron columns, in the corridors where clerestory light spills over both systems simultaneously.

The 60 cm raised floor is the unsung hero. By floating the ground plane on micropiles, the architects buried mechanical, electrical, and plumbing networks below a timber deck without trenching into the original stone floor. It is a strategy more common in data centers than in heritage buildings, and it solves the single hardest problem in adaptive reuse: how to deliver contemporary comfort without surgical damage to the host.

Poplar from 120 Kilometers Away

The material palette is almost aggressively local. Poplar, a fast-growing hardwood abundant in the Hauts-de-France region, was sourced within a 120 km radius and processed at the Alglave sawmill roughly 50 km from the site. Glue-laminated into posts and beams, it provides the primary structure. Spruce CLT panels, drawn from sustainably managed forests, form the floor plates. Partition walls use poplar timber framing insulated with wood fiber and wood wool, finished in Fermacell boards. Nothing exotic, nothing imported from a continent away.

Over 2,400 hours of prefabrication in workshop preceded on-site assembly, a strategy that compressed the construction timeline and slashed waste. The Cradle-to-Cradle framing is not marketing language here; every connection is designed for disassembly, every panel sized for reuse. When the lease expires, the timber could be re-milled, relocated, or composted. The 15.2 million euro budget (excluding tax) bought not just a building but a material bank.

Light, Thermal Constraints, and Honest Compromise

Heritage designation comes with friction. Double glazing, which would have dramatically improved thermal performance, was prohibited by conservation authorities. The architects responded by partially veiling the ceiling to reduce solar gain and thermal loss through the original single-pane glazing. It is an honest compromise, visible in the images where clerestory light washes in from above with a softness that suggests diffusion rather than full exposure.

The result is a building that performs well enough to function as a year-round campus but refuses to pretend it is a sealed box. Passive strategies, natural ventilation through the greenhouse geometry, and the thermal mass of the original brick and stone walls do much of the heavy lifting. The project accepts that a 19th-century greenhouse will never hit Passivhaus numbers and focuses its energy budget where it counts: on the new timber volumes that can be insulated properly.

A Permaculture Park as Infrastructure

The 6,053 m² park surrounding the palace is not decorative green space. Organized around permaculture ethics, it integrates low-tech urban agriculture with a local plant palette of fruit trees, berry shrubs, and aromatic herbs selected for minimal irrigation and maintenance. Experimental plots test vertical farming, aquaponics, hydroponics, and geothermal energy. For an engineering school focused on food systems, the landscape is as much a teaching tool as any classroom inside.

The restored rotunda greenhouse, now stripped of programmatic pressure and returned to plants alone, anchors one end of this ecological loop. It functions as a biodiversity refuge: a deliberate inversion of the original building's purpose, where plants were once exhibited for human pleasure and now inhabit the space on their own terms.

Plans and Drawings

The drawings tell the story of separation. The section cuts reveal the new timber frame floating inside the historic shell, daylight entering through the original clerestory and filtering down through the double-height nave. The axonometric exploded views make the modular logic explicit: a concrete micropile base, a post-and-beam poplar skeleton, CLT floor plates, and demountable partitions stacking into a legible kit of parts. The site plan shows the two circular corner volumes intact, the park wrapping the building in productive landscape. The detail drawing of the laminated timber post assembly, with its modular beam connections, is the project's clearest statement of intent: every joint designed for eventual undoing.

Why This Project Matters

Adaptive reuse projects often congratulate themselves for saving old buildings while quietly gutting them. Palais Rameau takes the opposite approach and follows it to a logical extreme. The new interior is structurally, materially, and conceptually detachable. It treats the historic monument not as a container to be colonized but as a host organism that might one day need its space back. That discipline, maintained across 3,950 m² of program and a 15.2 million euro budget, is rare enough to qualify as a contribution to the field.

The project also makes a quiet argument about supply chains. Poplar sourced within 120 km, processed 50 km away, prefabricated in a workshop, and lifted into place is not a radical proposition. It is simply what responsible construction looks like when an architect commits to it. Atelier 9.81 has delivered a building that functions well, respects its context without genuflecting, and could, if the world changes, disappear without a trace. That combination of ambition and humility is worth studying.

Palais Rameau by Atelier 9.81. Lille, France. 3,950 m² (palace) plus 140 m² (guardian's house) and 6,000 m² park. Completed 2024. Photography by Nicolas da Silva Lucas.

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