House extensions in Annecy.

In Annecy, the picture is clear: land is scarce and the property market is among the most expensive in France. Finding a bigger, well-located house at the right price is often an uphill battle — and the cost of moving, including notary and agency fees, quickly adds up. In this context, extending your existing house becomes the most rational solution: you gain living space without leaving your neighbourhood, your schools or your lakeside lifestyle.

The needs are many: an extra bedroom when a child arrives, a home office for remote working, a master suite, a large bright living space, a garage or a veranda. Rather than turning everything upside down, an extension lets you add exactly the space you need, in harmony with the existing house. The result: renewed comfort and a real increase in property value — in Annecy's tight market, every well-designed extra square metre adds lasting value to your home.

You still have to deal with the constraints specific to the Annecy area: a strict local plan (PLU), often sloping plots, a footprint sometimes already largely used, and — for lakeside towns such as Veyrier-du-Lac, Menthon-Saint-Bernard or Sevrier — the requirements of the Loi Littoral (coastal and lakeshore protection law). This is exactly where our role as project manager comes into its own: designing a project that is realistic, compliant and harmonious. To see extensions in the context of all our work, discover our projects in Annecy and Haute-Savoie.

Extending a house is not just about “pushing the walls out”. There are three main routes, and the right choice depends on your plot, your local plan (PLU) and your needs. A ground-level extension is the most common solution: a single-storey room or a volume attached to the house is added. It requires the plot to still have buildable footprint and the local plan to allow this layout — which is not always the case on Annecy's small plots.

When the plot is fully built up, adding a storey to the house becomes the best option: a floor is added on top of the existing building, gaining significant space without touching the garden or the footprint. It is a particularly well-suited answer in Annecy, where land is short. We explain this solution in detail on our dedicated page on adding a storey to a house in Annecy.

Finally, when the roof space already exists, a loft conversion is by far the most economical way to create a bedroom or an office: no foundations, no increase in footprint, simply making the most of wasted space. To find out more, see our page on loft conversions in Annecy. During our first visit, we study all three options and steer you towards the one that offers the best balance of space gained, cost and planning constraints.

Once the principle of an extension is agreed, the construction method still has to be chosen. A timber frame extension is winning over more and more Annecy homeowners, and for good reasons: it is light — a decisive advantage on sloping plots or soils with low bearing capacity around the lake — quick to build thanks to prefabricated panels, and naturally very thermally efficient, which makes RE2020 compliance easier. Timber also fits perfectly with Alpine architecture and allows large glazed openings towards the lake or the mountains.

A traditional masonry extension (concrete block, brick, concrete) remains entirely relevant: it offers great durability, excellent thermal mass that is welcome in midsummer as in winter, and a consistent look that is ideal when the existing house is itself solidly built. On the other hand, it requires more substantial foundations and a slightly longer build.

There is no universal answer: the right choice depends on the ground, the local plan, the budget and the harmony you want with the existing building. As project managers, we advise you impartially — we do not sell a material, we design the best extension for your house. And we build in both timber and masonry, which guarantees objective advice. Discover all our expertise on our services page.

Before any extension project, three notions are worth understanding. The footprint is the ground area your building occupies: Annecy's local plan (PLU) sets a maximum ratio per plot, as well as rules on distances from boundaries and from the road. On Annecy's often small plots, this footprint is sometimes almost used up already — hence the frequent appeal of adding a storey, which uses no additional footprint.

Annecy's local plan (PLU, Plan Local d'Urbanisme) is strict: it governs heights, roof pitches, materials, colours and siting. Certain areas — around the old town, protected zones, areas subject to the Loi Littoral in lakeside towns — impose stricter requirements, sometimes subject to the opinion of the ABF heritage architect (Architecte des Bâtiments de France). Checking the rules that apply to your plot is the very first step, and we always take care of it.

Finally, once it exceeds a certain area threshold, the extension is subject to the RE2020 environmental regulations, which require a high level of insulation and energy performance. Far from being a constraint, this is an asset in the Alpine climate of Haute-Savoie: a well-insulated extension means guaranteed winter comfort and controlled bills. Timber frame makes these requirements much easier to meet. To find out more about energy performance, see our page on energy renovation in Annecy.

The planning formalities depend on the area created. Below 20 m² of floor area or footprint, a prior declaration (déclaration préalable) is sufficient. Above that, a building permit is mandatory. And once the extension takes the total floor area of the house above 150 m², using an architect also becomes mandatory — a requirement we meet, as our managing partner is an architect.

That is the whole point of entrusting your extension to a project manager. Our role: study the local plan, design the project, draw up the plans, prepare and file the permit or declaration with the town hall, then coordinate all the trades — earthworks, structural work, roof framing, roofing, joinery, insulation, electrics, plumbing, finishes. You have a single point of contact, a single overall quote, a single well-managed schedule.

This turnkey approach spares you the headache of coordination and unpleasant budget surprises. We plan every stage, supervise the works, check quality and meet deadlines. As an RGE-certified company, we design efficient extensions that comply with the latest regulations. To estimate timescales and formalities in more detail, see our guide house extensions: prices, permits and timescales.