Adding a storey to a house in Chambéry.

In Chambéry, nestled between the Bauges and Chartreuse massifs, land is scarce and expensive, and plots in the centre are often narrow and semi-detached. When the family grows or remote working calls for an extra room, pushing the walls out at ground level quickly becomes impossible: there is no garden left to sacrifice and not enough setback from the boundaries. Adding a storey solves exactly this problem — it adds a floor upwards and creates up to a whole level of living space without touching the footprint.

On older town houses in the centre, detached houses from the 1960s to 1980s and villas in neighbouring towns, adding a storey lets you gain bedrooms, a study, a master suite or a panoramic living room facing the peaks. It is also an excellent way to build property value: on an already built, well-located plot, the cost of the space created by adding a storey is often lower than the price of equivalent land, and the value of the house rises significantly after the work.

Finally, adding a storey is an opportunity to upgrade the thermal envelope of the building: when the roof is removed to build upwards, the new structure is insulated to current standards and the insulation of the existing floors is often improved too. In the cold winters of the Chambéry valley, the gain in comfort is immediate. To go further, discover our approach to energy renovation in Chambéry.

A successful storey addition depends above all on the feasibility study. The first question is always the same: can the house carry an extra floor? We have an engineering office check the load-bearing capacity of the foundations, load-bearing walls and existing top floor. On older town houses with stone or rammed-earth walls, this check is essential; if capacity is limited, we favour a lightweight timber-frame structure or plan appropriate strengthening.

Next comes the regulatory side. In Chambéry, the Grand Chambéry local plan (PLU) strictly governs maximum height, building envelope, overlooking and siting. In the conservation area of the old town and around historic monuments, the binding opinion of the ABF heritage architect (Architecte des Bâtiments de France) is required on height, massing, materials and the appearance of roofs. As project manager and architect, we design a compliant scheme, submit the building permit and follow its processing through to the decision.

The work itself is quick, especially with timber frame prefabricated in the workshop: once the old roof has been removed, the new structure is erected and the building made weathertight in a few days to protect the interior. On the narrow plots in the centre, where access, the crane and removal of rubble are restricted by the street, we organise logistics to limit disruption and coordinate all the trades (roof structure, roofing, windows, insulation, finishing trades) through to handover. This well-controlled approach to the site is also the one we apply to renovation and construction in Chambéry.

Timber-frame storey addition — the leading technique for raising an existing house. Three to four times lighter than masonry, timber frame limits the load on the foundations, is prefabricated in the workshop and goes up very quickly on site. It is ideal on the narrow plots of central Chambéry and on older town houses whose old structure could not carry a concrete-block floor. With strong thermal performance, it suits traditional roofs just as well as contemporary architecture.

Roof raising — when the existing loft is too low to be converted, we carry out a roof raising: the roof structure and roofing are lifted by a few tens of centimetres to a metre to create a genuinely habitable ceiling height. It is an intermediate solution, lighter than a full floor, that turns an unusable attic into living rooms — subject to the building envelope permitted by the PLU.

Masonry storey addition — on houses whose foundations and load-bearing walls allow it, adding a masonry floor (brick, concrete block, aerated concrete) extends the existing building in keeping with the original materials. Heavier, it requires a thorough structural study, but offers perfectly consistent appearance, valued in protected areas where the ABF ensures the coherence of the built environment.

New roof and roof structure — every storey addition comes with a new roof structure and a new roof: an opportunity to install watertight, durable roofing with a high-performance underlay and carefully finished zinc flashings, respecting the colour and type of tiles required by the look of the old roofs in the Sardinian centre.

Insulation and windows — the space created is insulated to current standards and fitted with new windows. Thermal bridges are eliminated, light is brought in through wide openings or roof windows, and solar gain is optimised towards the surrounding mountains.

There are three main ways to gain space, and the right choice depends on your plot, your budget and the PLU. Adding a storey adds a whole level upwards without reducing the garden: it is the best solution when land is lacking, which is common in central Chambéry. It creates the most floor area, but requires a structure capable of carrying the extra floor and a building permit.

An extension at ground level is ideal if you have land: it creates single-storey space, often easier to live in, but reduces the open part of the plot — a delicate trade-off on narrow sites. To compare the approaches, see our page on house extensions in Chambéry.

Finally, a loft conversion uses an existing volume under the roof: it is the quickest and most economical solution, but it is limited by the available ceiling height. If your loft is too low, roof raising or adding a storey takes over. Find out more on our loft conversions in Chambéry page. Whichever route you choose, we help you decide and manage the whole project; see also all our services.