A saturated market, betting on independence

GL: We founded our practice out of a growing desire to develop an architectural approach of our own. After several years working as salaried architects in Switzerland, we wanted to bring back to France the convictions and principles we had developed there. We started out in Switzerland, where family connections helped us land our first commissions, whilst keeping our salaried jobs.

MB: Looking back, we also recognise how much the economic context shaped our decision. Finding salaried work in France has become increasingly difficult — practices lack the financial visibility to plan ahead, and the situation gets harder every year. Setting up on your own practice is one way to respond to that. It opens up real personal and professional possibilities, though we are aware that more new practices also means more competition and a more saturated market.

GL: Setting up our own office offers the promise of freedom, mobility, and independence. Many salaried architects go it alone after feeling their prospects for growth within a practice have stalled. The security of a salary loses its appeal when the constraints mount up. After about ten years of practice, there tends to be a moment of reckoning — a point at which confidence and fulfillment push people towards independence and the risks that come with it. That shift is never purely professional. It also coincides with stronger personal and family priorities that our generation, unlike those before us, is willing to talk about openly. Work-life balance is something we actively defend, and entrepreneurship — for all its sacrifices — feels like one answer to that. We belong to a generation that is increasingly committed to defending its own rights and those of future generations, whether environmental, social or political.

MB: These concerns lie at the heart of our work. We try to work as collaboratively and inclusively as possible, bringing together architects, urban planners, landscape architects, artists, academics, craftspeople and others. Where some see a fragmented profession, we see the formation of collectives, professional groups, and associations within which ideas evolve, take shape, and become concrete.

From Lausanne to Rennes, via a prize and a reckoning

GL: We met at the École Nationale Supérieure d'Architecture de Bretagne, a school with a strong focus on situated architecture, on buildings that respond to their specific context. That was a language we both wanted to develop further, which is part of what drew us to Switzerland. Marine went on to do her master's at the École Polytechnique Fédérale de Lausanne in 2011, after a year working in a practice, while I went straight into practice after graduating. The next ten years were formative. I spent eight of them taking on growing responsibility in a small practice, then two more in a larger office working on bigger projects.

MB: My path was different, though equally formative. After a difficult early experience, particularly in terms of working conditions, I stepped back to question the direction I wanted to take, moving into an academic role as a teaching assistant at the EPFL alongside a job in an acoustics consultancy. The decision to return to France, and specifically to Brittany, began to take shape in 2018, for personal reasons. Rennes felt like the right choice,  a return to familiar territory, with an architectural scene that at the time felt open. We raced to build the identity of our own practice whilst still in our salaried jobs.

GL: Our strategy was to use the renovation of our own newly purchased house as a demonstration of what we could do, a project where we had complete freedom. The main goal was to develop a network of professionals and clients in the Rennes area.  That house gave us visibility quickly, winning the Prix d'Architecture de Bretagne in the "Transformer pour habiter" category in 2022. But we also ran into real difficulties with contractors and clients. Our way of working — shaped by Switzerland, by its distinct construction culture and economic context — did not always translate easily into the Rennes context.

MB: Finding our footing took time and required a lot of adjustment. That period of questioning coincided with the early steps of Guillaume Lesage Architecte, the name the practice first operated under, with me in an informal associate role. At the same time I was directing the Team Solar Bretagne association, chaired by the architect Philippe Madec, founder of the Mouvement de la Frugalité Heureuse. That connection, to a set of environmental and social values, came at exactly the moment we were defining what the practice stood for, and it pointed us clearly in that direction. After ten years of practice, and through a series of encounters both planned and fortuitous, we are finally working on projects that reflect our values.

Shared narrative, physical model, material sample

MB: On most of our projects, we face the same tension many architects do: an ambitious brief and a tight budget. Rather than letting that become a confrontation, we try to bring our clients around to a different way of thinking, one that opens up architectural possibilities they had not considered.

GL: We also work almost entirely on existing buildings, which brings its own challenges, and where climate questions quickly become central to the brief. We start by building a shared narrative with our clients  that gives us room to explore different possibilities before settling on a direction. We are naturally curious, so we draw on a wide range of carefully chosen architectural references. They help us understand where our clients are coming from, challenge the brief, and guide the project in a direction that feels right. We rarely produce renderings. Instead, we combine our technical drawings and preliminary cost estimates with a selection of reference images built up throughout the design process — not as models to copy, but as a way of understanding what makes a project work and finding our own response. Physical models and our materials library, which we have been building up over the years, are the other constant tools we use to bring clients and collaborators along with us.

MB: The model is a tool everyone can understand, and it opens up the conversation at every scale: at 1:100, to discuss a proposal with the Architecte des Bâtiments de France; at 1:50, to help a client picture a loft conversion; at 1:20, to work through a fit-out with medical and administrative teams. We pair that with a hands-on engagement with materials — bringing in a curated selection of samples to work through colour, texture, and finish together. These tools stay in dialogue throughout the project, with one aim: making sure everyone involved shares a clear understanding of what we’re trying to achieve.

Constraints, colour, and the existing

GL: Tight budgets and ambitious programmes are the norm for us. Rather than pushing back, we have developed a genuine appetite for repurposing — learning to turn constraints into opportunities, as in judo, where you use your opponent's force rather than resist it. Almost every project requires steering clients away from what they initially had in mind, sometimes towards the opposite of their first instinct.

MB: On the renovation of a 1970s architect-designed house, for example, we persuaded our clients to convert the roof space rather than fit out the basement. That decision improved the building's thermal performance and opened up new views of the surrounding landscape. Atmosphere and comfort are always central to how we make the architectural argument, and they help clients understand our approach. We guide our clients through questions of use — working carefully on thresholds and boundaries, on their depth and how they are lit — whilst keeping structural questions firmly in view.

GL: Reuse runs through the design process from the very beginning, not as an afterthought. Colour matters just as much. Our thinking on colour was shaped by time spent working alongside the artist and architect François Seigneur and the Lausanne practice NB.ARCH. When we arrived in Switzerland, we wanted to design in immaculate white, drawn to its modernity. Today we do the opposite, looking for luminous, coloured atmospheres in every project. We research colour constantly and bring that research into the shared narrative we build with clients, so that nothing is left to chance or arbitrary preference.

Built work

MB: One of our most significant projects — though it contains very little architecture in the conventional sense — is the fit-out of the Centre de Santé du Blosne, completed in 2025. We are patients there ourselves. The centre does remarkable work in our neighbourhood in Rennes, and it was under real threat when government subsidies were withdrawn. The project involved relocating into a new building under construction next door. Community health means something specific: a local, participatory approach to health problems, where everyone is involved in managing their own care. The team wanted that same spirit to run through the fit-out. In early conversations during the consultation, we started looking at the move through the lens of reuse, and proposed building the project collectively — using a large-scale 1:20 model as the main working tool, developed progressively across meetings with both staff and patient groups.

GL: We listened to how they wanted to practise medicine and welcome patients differently, and those conversations led to real architectural questions: how do you design a consulting room built around a table or a bench rather than a desk? How do you plan a layout flexible enough to accommodate other practices? The budget was very tight, so we began with a full inventory of their existing furniture and worked out how to redistribute it in the new space. The whole project was built around what was already there. We also helped them find subsidies and set up a professional integration programme, bringing in youth construction associations to handle some of the bespoke joinery, furniture, and assembly work. There were two or three intense days on site with the whole team and all partners working flat out. Everyone agrees that doing it that way — together — helped the staff and users genuinely take ownership of the new space.

MB: We are currently working on another project we find equally exciting: five households from the same family moving into a former agricultural hamlet built in stone and earth, on the outskirts of Rennes. The project is genuinely complex, several structures ranging from habitable to barely so, a programme that has to work for the group as a whole and for each individual household, and a substantial sanitary and energy upgrade running alongside everything else. It is an intergenerational communal living project, and we are very glad to be part of it. The physical model has proved, once again, to be the most effective tool for keeping everyone aligned — on the layout, the phasing, and the ongoing conversation between households as the project develops.

Maintenance, solidarity, and reuse

MB: Three concerns run through everything we do, and they often come together in the projects that matter most to us. We believe buildings should be cared for over time — repaired, adapted, and improved rather than replaced. Housing renovation has become an increasingly central part of our practice, and we are committed to good-quality, dignified, affordable housing for everyone.

GL: Over the years our projects have grown in scale, and we are starting to work with other practices on much larger schemes,  something we did in Lausanne too. That combination of Swiss experience and a growing understanding of our local context makes those collaborations genuinely stimulating, and we are working on a range of  commissions, notably in the historic centre of Rennes. We are also committed to working with social and community organisations, whatever the scale, alongside partners who share our values of solidarity and mutual support — and we hope to do more projects like the Centre de Santé Communautaire du Blosne, which occupies an important place in our work. Reuse, meanwhile, is embedded in everything we do. We want to push it further, to larger scales and eventually to structural matters too. The more we do so, the easier it becomes to show clients and collaborators what it can actually achieve.