Price of a
timber deck.

A timber deck is made up of two works that are priced together: a frame (posts, beams and joists, or bearers laid on pedestals) and a decking, that is, the boards you walk on. The price per m² depends first on the former, far more than on the species of the boards.

A deck laid on a slab or already stable ground needs only bearers wedged on adjustable pedestals. A raised deck, at the level of an upper-floor living room or above sloping ground, calls for a real frame: posts founded on concrete pads, beams, a wall plate fixed against the façade. This is the most frequent case in our quotes, and the most expensive.

The very low prices per m² often read online correspond to boards laid on a support that is already ready. Our only line of this type, a decking redone on the existing structure of a balcony, comes to around €100 excl. VAT per m²: this is the order of magnitude of the decking alone, not of a complete deck.

Ranges taken from our 2024-2026 quotes in Savoie and Haute-Savoie, supply and installation by our teams, rounded. The amounts including VAT apply the VAT rate of each case, explained below.

These figures come from four projects: a modest base, which we prefer to show as it is rather than widen it with prices we have not charged. A line reads "estimate" when the quote itself presents it as a budget to be confirmed with the board supplier. We have no quote for a deck in composite boards: we therefore do not publish a price for this material.

One of our 2026 quotes concerns a 35 m² raised deck, 10 m long, widening from 1.20 m to 3.50 m along the house. It is made up of three lines:

The balustrade weighs almost as much as the deck itself. Per m², the complete work comes close to €860 excl. VAT, more than double the price of the structure and boards. This is why we price each item on its own line: two offers can then be genuinely compared.

The height. Beyond one metre high on a load-bearing structure, the deck falls under the rules of timber framing (NF DTU 31.1) and no longer under the decking DTU alone. Timber sections, bracing, foundations: everything grows with the height.

The support. A sound slab allows bearers and adjustable pedestals to be laid directly. On earth, concrete pads are needed under each post: around €600 excl. VAT each in our quotes, excavation and reinforcement included.

The boards. Within a single quote, going from pressure-treated pine to a modified wood guaranteed for 30 years raises the m² from €430 to €750 excl. VAT, with an identical structure.

The terrain. On the hillsides of Lac du Bourget or Lac d'Annecy, a deck often makes up several metres of level difference on the downhill side: longer posts, difficult access for materials. Our project Les Tourelles, on the heights of Aix-les-Bains, thus carries a terrace suspended above the void.

What goes with it. Balustrade, stairs, lighting, a French window to get onto it: so many items added to the price per m².

The detail of balustrade models and prices is in our guide to the price of a balustrade. If you are hesitating between timber and concrete, our guide to the price of a concrete slab prices the poured terrace; for comparison, our quotes for porcelain stoneware slabs on adjustable pedestals range from €120 to €170 excl. VAT per m², on five projects.

Timber decks fall under NF DTU 51.4, "Outdoor timber decking" (Platelages extérieurs en bois). It distinguishes decking for private use, attached to or near a dwelling (type 1), from all the others: offices, public-access buildings, urban developments (type 2). The loads, and therefore the sections of boards and bearers and their spacing, change from one to the other.

According to the Platelage bois (timber decking) sheet of the French National Timber Federation (Fédération nationale du bois), most decks fall under use class 4, the most exposed to moisture. Boards can drop to class 3.2 if the design limits standing water, and to class 3.1 under cover. A board must be at least 19 mm thick, at 18% moisture content (standard NF B 54-040). Our quotes provide for 27 mm boards and class 4 bearers.

The same sheet insists on service life: keep the bearers away from the ground, let air circulate under and at the sides of the boards, screw with stainless steel without driving the screws in too far, give a slight slope for drainage if possible, and brush a preservative onto the cut ends of treated timber. For maintenance, it advises cleaning twice a year with a brush and water, and advises against the pressure washer, which damages the surface of the wood.

Boards, cladding, stairs: the same use-class questions arise for all exterior timber, as our guide to the price of timber cladding shows.

As soon as a fall of more than one metre is possible, standard NF P01-012 requires a protective element. The Construction and Housing Code (article R134-59) sets the minimum height of a balcony or terrace balustrade at 1 m, which may be lowered to 0.80 m when the balustrade is more than 50 cm thick. For a raised deck, the balustrade is therefore almost always part of the project, and of its budget.

The stairs down to the garden follow the same logic: in one of our quotes, a straight staircase with metal stringers and solid timber treads, code-compliant handrail included, cost €1,800 to €2,440 excl. VAT depending on the version.

Permission. According to the official service-public.fr sheet, a ground-level deck is exempt from planning permission, except in a protected area, where a prior declaration (déclaration préalable) is required whatever the area. A raised deck creates ground footprint (emprise au sol), that is, the vertical projection of the structure, overhangs included. In an urban zone of a local plan (PLU), a prior declaration is enough up to 40 m² of ground footprint; beyond that, a building permit is needed. Outside an urban zone, the threshold falls to 20 m². The town hall alone judges what is "ground level": it is better to consult it before drawing. Our guide to the prior declaration details the file.

VAT. Building a deck falls under the standard rate of 20%, whatever its area: this is the position of the tax authority, restated in a ministerial answer published in the Journal officiel on 14 July 2015. A deck is neither enclosed nor covered, so it does not count towards floor area. On the other hand, resurfacing an existing balcony or terrace, in a dwelling completed more than two years ago, remains at 10%, as does installing a protective low wall. Our guide to VAT on building work explains the other cases.

At NovAlp, our salaried carpenters and joiners cut and assemble the structure, then lay the boards; our masons pour the pads and, if needed, open the façade for the French window. The balustrade, stairs and lighting appear in the same quote, each on its own line, under a single contract.

For a raised deck, we start with a survey: fall height, nature of the ground, possible bearing points against the house, local plan (PLU) rules. It is this survey that sets the type of structure, and therefore the price, well before the choice of boards.