Is Paris’s Wood Up a template for future timber housing projects?

Is timber a functional proposition for housing in Europe’s densest city? This question was posed in a competition held by the City of Paris seven years ago, hoping for an intelligent solution, and a potential template for future projects.

With their proposal for a 16-storey tower on the banks of the Seine, competition winners LAN Architecture (a 20-year-old practice with significant experience in social and student housing) and REI Habitat (a youngish developer with a commitment to French timber and reforestation) undertook to achieve the necessary density while also meeting strict Association Pour le Développement du Bâtiment Bas Carbone (BBCA) standards (with ensuant financial benefits).

In parallel, the project was required to rehabilitate its surroundings at the edge of Paris Rive Gauche in the 13th arrondissement, gradually revitalised by the arrival of the Bibliothèque National in 1996; the transfer of the Université Paris Cité campus a decade later; and, more recently, by Snøhetta’s headquarters for Le Monde. All have brought culture, energy and an abundance of international eateries, creating a determinedly post-industrial neighbourhood.

Wood Up sits at its easternmost edge, abutting the still-industrial hinterlands of Ivry sur Seine, considered ‘elsewhere’ by most Parisians, and separated only by the roaring 1960s concrete of the Boulevard périphérique. At 50m high (the most currently allowed for residential buildings in Paris), it’s a riverside landmark – the tallest wooden building in France and, depending on definitions, the second tallest in Europe. Its creation is labelled ‘an unprecedented typological exploration’ on the practice’s website. Eschewing such jargon, LAN’s co-founder Umberto Napolitano bluntly calls its genesis ‘a nightmare – this idea of using wood for the first time, there was no regulation that clearly made a statement about what you should or shouldn’t do’.

As such, Wood Up served as an experimental research project for both practice and city, with many of its elements requiring laboratory testing from scratch (‘nothing is standard in this building’, says Napolitano). Consequently, a significant chunk of the current regulatory framework is a byproduct of its development.

The Notre-Dame fire in 2019 further complicated matters, with the newly evolved regulations changing ‘day by day’ just as final drawings were prepared. In addition, construction was slowed by the Olympic Village’s rapacious and competing appetite for timber. As a result, the economy and speed – ‘which is also, in the end, money’ – often ascribed to prefabricated timber proved elusive. Even so, the overall cost per square metre has still ended up little more than that of conventional equivalents: €2,700 instead of approximately €2,500 for concrete.

Wood Up is a hybrid structure, with a three-storey concrete base tackling the complexity of the site’s 7m drop to the Seine and creating new connections between river and neigbourhood. There are entrances on each of these storeys – one to the riverbank; another to an intermediate (if still incipient) piazza; and the main entrance at the top, giving access to a transecting public walkway and a shared space with communal seating. The base also contains two commercial units – a café and a climbing wall – along with bike and car parking.

The glulam timber structure above is braced by the concrete of circulation areas, while floors are fabricated with a wood-concrete composite. But the principal material is beech. Wood Up is the first building constructed from France’s most plentiful timber, transported to the site by barge from Normandy. Two deep rings of columns rise up the tower on a 3.9m grid. The inner ring skirts the apartments, employing beech’s compressive strength to meet the structural demands. Fabricated from moisture-resistant Douglas fir, the outer columns stabilise the building and are clad in plywood to accommodate services. Each of the latter columns stretches two storeys up the facade, halving the apparent number of floors when viewed from afar, creating a powerful geometric effect.

Within, the storeys act in pairs, their modular construction allows for a range of layouts to accommodate different lifestyles, and facilitates vertical and horizontal alterations over time. Larger family-oriented flats (including corner duplexes) are on the lower storey, with smaller ones (some of them studios) above. The former have access to an encircling precast concrete balcony that acts as both a fire break and a ‘common micro-space’. Inside, both columns and beams are highly visible (and fragrant) – the latter were manufactured from pine as it possesses the necessary bending strength. Retaining the exposed timber despite official concern required persistence, but the result is that ‘you are living in wood’, as Napolitano puts it, adding: ‘We wanted to reveal the very nature of the building in daily lives.’

Alongside this timber framework, floor-to-ceiling windows dominate the interiors. ‘At the end of the day,’ says Napolitano, ‘this is literally a glass building with a structure in wood that acts as a system of columns and beams to keep the glass in place.’ Achieving a level plane for the aluminium-framed windows, many sliding, was a technical challenge, especially given the different rates at which timber and concrete settle and shift over the years.

Another priority was limiting heat gain but, Napolitano says, ‘the glass is protected by the morphology of the building itself’ thanks to the double ring of deep columns, the encircling balconies, and the small ledges on alternate floors added for privacy and fire resistance. Also helping are solar-control film in windows and aluminium-backed thermal curtains.

The effect of the windows is ‘to bring the city into the flat, embracing the geography of the site and its views – from the tower, two conditions and two worlds are visible’. Each apartment benefits from wonderful prospects – some in multiple directions – of romantic sunsets over the Pantheon, Notre-Dame and the Île de France; to the wonky new Tours Duo by Jean Nouvel and the 1970s towers of the Quarter Asiatique; or to the smoke rising from the ageing if still mighty Syctom waste-incineration plant in Ivry, just beyond the Boulevard péripherique. The noise from the latter initially caused the architects to doubt the site’s viability but rigorous acoustic measures and the recent introduction of a 30kph speed limit have transformed the ring road into little more than a hypnotic perpetual-motion machine.

LAN’s final ambition, says Napolitano, was to undertake ‘an exploration of what it means to build collective housing today. Putting together 132 flats means creating a community that needs common space.’ Of Wood Up’s 8,900m², roughly 2,000m² is allocated to shared space. Most notable are the roof garden – with its photovoltaic panels, planters and individual plots for each apartment – and the striking two-storey void that punctures the building on the eighth floor (aided by a rare steel beam), providing the building with its visual signature. This 300m² terrace is open to all residents, whether for exercise classes and social gatherings or for just viewing the sun setting over the city. Bookable via the building’s on-site concierge, it is to be scattered with furniture made from offcuts and will be monitored on an ongoing basis by a team including the architects.

‘It’s great to provide this space, but the difficult part is how to regulate it,’ says Napolitano, ‘how, in collective housing, you can be sure that at three in the morning, there isn’t a party going on; how people can use it at a specific time; how you can encourage encounters between residents. It’s a gamble, and we’ll be really interested to see how it works and if it can be reproduced elsewhere.’

There is another metric of success for Wood Up: popular reaction. ‘The street,’ Napolitano says, ‘likes it – everyone likes it.’ This reaction produces a certain uneasiness. ‘I worry about populist approaches to these complex questions,’ he adds. ‘There isn’t a single answer but wood currently has a sustainable image that doesn’t allow for debate, despite sometimes being just a marketing argument. It’s too easy to say that, because it’s wood, it’s sustainable. That’s the case here, but I can give you 10 examples where using wood is not the best approach … We have to challenge ourselves to use wood in a precise way, in a more responsible way, compensating with other approaches: rammed earth, bio-materials, retrofitting, recycling existing materials. Everything is related, so solutions should not be dogmatic … once you radicalise one answer, it is not the right answer.’

Reinforcing this message, current LAN projects include the Grande MAXXI project in Rome, which uses recycled brick from across Lazio and Tuscany; a new rammed-earth project in the Hébert district of northern Paris; and the ‘climatic transformation’ of the 1970s Rives de Seine tower across the river from Wood Up, involving the dramatic reconfiguration of its facade to reorient its 16 glass-and-concrete storeys.

Despite the expertise gained, LAN is not currently working on another such lofty timber tower. ‘We are doing five or seven-storey projects,’ says Napolitano. ‘You need to have a strong motivation to undertake vertical towers – from a city or from ecological labels – or you need a strong commercial aspect.’ Wood Up is a significant and successful project that delivers environmentally and economically and as a piece of city. But it has also confirmed Napolitano in his pragmatic belief that flexibility will be key to achieving a sustainable future.

In numbers

Apartments 132
Budget €25.1 million
GIFA 8,949m²
Roof 700m²
Void 300m²