Loi Littoral:
building by the lake.

Many owners discover the Loi Littoral when they are refused a permit. Yet the mechanism is automatic: article L121-1 of the Planning Code refers to article L321-2 of the Environment Code, which classes as coastal communes those on the shores of inland bodies of water of more than 1,000 hectares.

Lac du Bourget far exceeds this threshold. Being subject to the law is therefore not the result of any local decision or discretionary list: it follows solely from lying on the shore. No commune can opt out, and no elected official can exempt you.

In Chautagne, the three communes on the lakeshore are Chindrieux, Conjux and Saint-Pierre-de-Curtille. The other five — Serrières-en-Chautagne, Ruffieux, Chanaz, Motz and Vions — are not subject to this regime, which does not mean they are free of constraints: the flood risk prevention plan (PPRi) and environmental zoning apply there.

The Chautagne PLUi regulations incorporate article L121-16 of the Planning Code: outside built-up areas, buildings or installations are prohibited within a 100-metre lakeshore strip. The only exemptions are buildings needed for public services or for economic activities requiring immediate proximity to the water.

But the regulations provide for an exception that changes everything for an owner: existing dwellings with a floor area of 50 m² or more may be repaired, rehabilitated and refurbished — without any change in volume. The rehabilitation of existing outbuildings is also permitted, under the same conditions.

The consequence deserves to be stated plainly: on a large part of the lakeshore of these three communes, renovating the existing building is the only legal option. That is not a bad thing. A property located in a strip where nobody will ever build again, properly rehabilitated, retains a value that nothing will compete with.

Beyond the 100-metre strip, the Loi Littoral defines a second perimeter: areas close to the shore. The PLUi regulations refer here to article L121-13 of the Planning Code: refurbishing existing buildings remains permitted provided it does not constitute an extension of urban development.

Above all: outside built-up zones, new buildings are only allowed there in continuity with existing towns and villages, after consultation of the departmental commission for nature, landscapes and sites (CDNPS). An isolated house in the middle of a meadow, even outside the 100 metres, therefore comes up against this continuity principle.

It is this second perimeter that most often comes as a surprise, because it is less well known than the 100-metre strip and its boundaries cannot be guessed from the road.

Let us be clear, because this is the point on which we refuse to bluff: nobody can tell you from memory whether your plot lies within the 100-metre strip or in the areas close to the shore. These perimeters are identified on the PLUi zoning plan and defined in the explanatory report. They are read, not estimated.

Be wary of anyone — estate agent, company, neighbour — who tells you otherwise without having opened the plan. A project designed and then rejected costs infinitely more than a check carried out at the right time.

It is the first thing we do, free of charge, before committing you to a study: consulting the zoning, the applicable regulations and the easements. Only then do we talk about the project — and we tell you frankly whether what you have in mind is possible, or whether it needs to be redirected towards rehabilitation.