Planning permission in Saint-Gervais: strict, slow and worth it

Rethinking the design

When we looked properly at the plans that came with the plot, the integrated garage looked like dead space. A big, cold room for a car, inside a chalet we were building for people.

In one respect we were lucky. Every chalet in France starts with a permis de construire (building permit), and ours was already granted. We could have started building straight away.

But why not put a garage on the side, and turn the old garage into another room? It seemed a modest change. In Saint-Gervais, “modest” and “planning” don’t really belong in the same sentence.

Changing a permit you’ve inherited

When you buy a plot that already has a permit, the permit comes with the land. What you can’t do is quietly build something different. Any change means going back to the mairie (town hall), either with a permis de construire modificatif for adjustments or a fresh application for bigger changes.

Ours needed formal approval. Turning a garage into a room changes the chalet’s living space. Moving the garage outside changes the footprint and how the chalet looks from the lane. Either one alone is enough to need permission.

Why we needed an architect anyway

In France, once a building reaches 150 m² of floor area, using a registered architect is a legal requirement. At around 170 m², Chalet Miage was always going to be over that line.

That turned out to be a blessing. Our architect was local and knew the planning rules, and the people at the mairie, inside out. We went back and forth with different designs. The planning team at the town hall were genuinely helpful too, telling us early what was and wasn’t likely to be accepted.

Strict by design

People who’ve built in Saint-Gervais tend to describe the planning regime as either wonderful or maddening. Both are true.

The mairie is exacting, and unapologetic about it, because the point is to keep the town looking like the town. The local plan (the PLU) and the landscape charter set out in real detail what you can build: the materials, the roof shapes and pitches, the heights, and how much you’re allowed to carve into the slope.

In practice, that meant:

• No walls of glass. Grand Designs with acres of glazing are very much forbidden. Where bigger windows are allowed, you’ll often see timber slats breaking them up.
• No buried garage. The rules limit how much you can reshape the natural ground, so the tucked-away underground garage we’d pictured was never going to happen.
• Traditional forms. Timber, a stone or concrete base, and the right roof.

Arrive with a glass-box design and a tight deadline, and it’ll feel like a wall. If you came here, as we did, because the place looks the way it does, the strictness starts to make sense.

And yes, it’s slow

On paper, a building permit for a house is assessed in about two months. A modificatif can take longer. In reality, the clock you live by includes requests for missing documents, revisions, and a careful back-and-forth with a planning office that reads everything closely.

After months of paperwork and redrawn plans, two days after Christmas 2024, our modified permit came through. The best present we got that year.

What we’d pass on

• Assume any change to a granted permit needs formal approval. Don’t improvise on site.
• Find a local architect who knows the PLU and has a working relationship with the mairie.
• Read the PLU and the landscape charter early, before you fall for a design that can’t be built.
• Work with the local style (timber, a solid base, the right roof, modest glazing) rather than against it.
• Allow months, not weeks. Everything after this depends on it.

Looking at the chalet now, the rules didn’t water the design down. They shaped it. Chalet Miage looks like it belongs in Saint-Gervais because the rules more or less insisted that it would.