Cost to build a wooden deck in Luxembourg (2026)

A €5 500 HT quote at TVA 17 % invoices at €6 435 TTC; on a primary-residence project qualifying for 3 %, the all-in figure drops to €5 665 TTC — a €770 saving on the same scope.

Format drivers:

• Species choice — Douglas is cheapest and requires annual oiling; Ipé is the most durable (25–40 year service life) but heaviest and three times the material cost
• Substructure — concrete plots on an existing paved slab cost €15–€25/m²; screw piles into raw soil cost €35–€55/m² but avoid civil-engineering work
• Board orientation — diagonal or mixed patterns add €10–€20/m² in cut waste and labour
• Surface finish — factory-grooved anti-slip boards add €8–€15/m² over smooth boards

The near-fourfold spread reflects six concrete cost lines, not installer margin.

The six drivers that matter:

• Surface area. Every extra m² costs €140–€320 in material plus labour. Doubling from 20 m² to 40 m² does not quite double the price because the substructure has economies of scale, but it comes close.
• Timber species. Douglas at €45/m² in material; Siberian larch at €75/m²; Ipé at €160/m². The species alone can double the quote on the same square metres.
• Substructure and slope. A 0–2 % slope on existing paving needs only concrete plots. A 10–15 % slope demands screw piles, a graded membrane and drainage — adds €1 200–€2 800 on a 30 m² terrace.
• Edge detailing. A single clean edge on three sides is standard. Mitred corners, integrated step-downs, planter integration and aluminium edge profiles add €600–€2 400.
• Access and logistics. A front-garden terrace with lorry access is cheap. A rear-garden terrace reached via a 4 m-wide side passage adds €350–€900 in hand-carry time. Crane-truck delivery for Ipé bundles in urban Luxembourg-Ville costs €300–€550.
• TVA stance. 17 % standard versus 3 % super-reduced on a primary residence is a 14-point gap, worth €780 on a €6 500 net quote.

Scope creep on a terrace project is the main cause of budget overruns.

Included in a typical €6 500 quote for a 30 m² larch deck:

• Ground preparation and geotextile membrane against weed regrowth
• Screw piles or concrete plots as substructure, sized for LU frost depth (0,8 m)
• Pressure-treated softwood joists on 400 mm centres
• Siberian larch decking boards 27 mm, screwed with stainless A4 inox
• Perimeter edge profile and ventilated under-deck
• Removal and disposal of site spoil
• Commune notification where applicable
• Ten-year décennale cover

Usually not included — expect a separate line:

• Demolition of an existing terrace — €15–€35/m²
• Drainage to the sewer or rainwater tank — €350–€900
• Railings or balustrade — €90–€180/linear metre
• Integrated LED lighting — €45–€75/metre strip, plus €350–€650 electrician's declared drop
• Aluminium pergola over the deck — €1 600–€5 800 on a separate contract
• Annual maintenance oiling — €8–€14/m² per visit, normally every 12 to 18 months

Red flags:

• No mention of frost depth — plots set above 0,8 m lift in the first hard winter
• Galvanised steel screws instead of stainless A4 — they stain the timber within 18 months
• Quote silent on substructure ventilation — no air gap causes rot within 5 years
• A 5-year warranty instead of the 10-year décennale — only unregistered workers offer 5-year

A wooden terrace attached to the owner's primary residence qualifies for the 3 % super-reduced TVA rate via logement.lu when it replaces an existing surface or extends a living space that already existed. New detached garden decks are less clear-cut — the Administration de l'Enregistrement reviews case by case.

Rate in practice:

• Deck replacing a worn existing terrace on a primary residence older than 2 years: 3 % accessible, saving ~14 points
• New deck on a detached garden on a primary residence: 3 % usually accessible as an extension of the living area, subject to the certificate
• Deck on a second home or rental property: 17 % standard
• Deck on a new-build property under 2 years old: 17 % standard — the super-reduced rate kicks in at year 2

What a compliant invoice shows:

• Net amount per line (ground prep, substructure, timber, labour, finishing)
• TVA line at 3 % with logement.lu certificate number, or 17 % otherwise
• Timber origin certificate (PEFC or FSC) for tropical species
• Décennale policy number and Autorisation d'établissement reference
• ITM registration for the installation crew

Rate comparison on a €6 500 net project:

Always file the 3 % application on MyGuichet.lu before works start — the rate is not retrofittable once invoicing begins.

Terrace quotes diverge because scope is rarely stated the same way by two firms. A shared brief pulls the spread into a usable band.

The six checks that matter:

• Timber grade and origin. Douglas, larch, thermo-ash, Ipé, composite — each at a specific grade. Ask for the supplier name (Silvadec, Accoya, Eurowood) and the origin certificate.
• Substructure specification. Screw piles versus concrete plots, and the frost-depth number. A couvreur who cannot name 0,8 m as the LU frost depth is not thinking about the first winter.
• Fastening quality. A4 stainless screws or nothing. Galvanised fails within two winters on oak and Ipé.
• Drainage and ventilation. The gap under the boards must be at least 50 mm and ventilated at both long edges; drainage of the ground underneath must be stated.
• Warranty depth. Ten-year décennale on the structure, two-year workmanship on the boards. Timber warranties are manufacturer-only; insist on the brochure copy.
• TVA stance. 3 % or 17 %? Will the contractor apply the 3 % directly on the invoice with the logement.lu certificate, or does the client reclaim separately? Direct application is the only correct route.

A clean briefing pack:

• Measured plan with target surface, access width and slope
• Current surface (lawn, pavers, old terrace) with photos
• Preferred timber species and substructure
• Lighting and pergola intentions
• TVA position (primary residence, secondary, new-build)
• Delivery window (avoid November to March for installation)

Quotes on the same pack land within ±15 % of each other on price. A wider spread flags a scope misread.