Price by construction method and floor area
| Construction method | 120 m² house | 150 m² house | 180 m² house | Per m² |
|---|---|---|---|---|
| Masonry — block walls, concrete floors, timber roof | €95 000–€118 000 | €118 000–€148 000 | €142 000–€176 000 | €650–€980 |
| Masonry — cellular-concrete walls + reinforced concrete | €102 000–€125 000 | €128 000–€158 000 | €152 000–€188 000 | €700–€1 050 |
| Timber frame — open panel (site-built) | €108 000–€132 000 | €135 000–€165 000 | €162 000–€198 000 | €750–€1 100 |
| Timber frame — closed panel (prefab, passive-house ready) | €125 000–€155 000 | €156 000–€195 000 | €185 000–€232 000 | €870–€1 290 |
| Hybrid — masonry ground + timber upper | €112 000–€138 000 | €140 000–€172 000 | €168 000–€206 000 | €780–€1 145 |
Key cost lines inside the gros-œuvre scope:
- Earthworks + foundation — €18 000–€35 000 depending on soil, plot slope and whether a basement is built
- Slab + waterproofing — €85–€140 per m²
- Load-bearing walls (masonry) — €220–€340 per m² of wall
- Timber-frame walls (closed panel) — €280–€420 per m² of wall
- Intermediate floors (reinforced concrete slab) — €140–€210 per m² of floor
- Timber-frame floors — €110–€170 per m²
- Roof structure + under-roof membrane — €180–€260 per m² of roof
- Scaffolding (15–20 weeks) — €3 500–€6 500
Pre-VAT quotes. At TVA 17 % standard, a €130 000 net shell costs €152 100 all-in; at TVA 3 % (primary residence, logement.lu approved) it costs €133 900 — a delta of €18 200.
What the gros-œuvre contract covers
In Luxembourg, the term gros œuvre (Rohbau) refers to the load-bearing structure and weather-tight envelope. It is one of three contract packages on a typical build: gros œuvre, second œuvre (interior finishes), and corps d'état techniques (HVAC, electrical, plumbing). Confusion at the contract boundary is the single largest source of overrun.
Typically included in gros œuvre:
- Earthworks, backfill and foundation drainage
- Reinforced-concrete footings and slab
- Load-bearing external and internal walls
- Intermediate floors (beam, slab or composite)
- Stairwell voids and elevator shaft structure
- Roof structure (timber or concrete) plus under-roof membrane and roof covering to weather-tight state
- External wall render first coat (or bare block, depending on contract)
- Chimneys and flue structures if drawn on plan
- Scaffolding for the shell duration
- Site protection, access, waste removal
Typically NOT included in gros œuvre — separate contracts:
- External cladding or final render finish
- Windows, external doors and glazing
- Internal partitions (drywall or block)
- Insulation (floor, wall, roof) — often subcontracted by gros œuvre but separate line
- Screed for underfloor heating
- Electrical, plumbing, HVAC (corps techniques)
- Interior doors, stairs finish, flooring
- Kitchen, bathroom, painting
- Landscaping and external paving
Grey-zone items — confirm in writing:
- Roof insulation
- Window lintels and openings formwork
- Bathroom waterproofing slab
- Balcony structure and waterproofing
A good practice: line up the gros œuvre and second œuvre tenders in parallel, with the architect sitting on both sides. A single general contractor (entreprise générale) coordinates but charges a 6–12 % coordination margin.
Masonry vs timber frame — the 2026 trade-offs
The choice between masonry and timber frame drives roughly 15–25 % of the structural cost and shapes the rest of the build.
Masonry (block or cellular concrete):
- Structural cost: lower baseline (€650–€1 050 per m²)
- Site time: slower — 14 to 20 weeks for the shell, weather-sensitive
- Thermal inertia: high — buffers summer heat in LU climate, reduces peak cooling demand
- Acoustic performance: strong, especially at room-to-room and floor-to-floor
- Finishing adaptability: most finishes possible (render, cladding, natural-stone facing)
- Energy-class A/AA compliance: achievable with external-wall insulation (ETICS) at 16–22 cm
- Resale value: well-understood by LU buyers and banks
Timber frame (closed panel, prefab):
- Structural cost: higher baseline (€870–€1 290 per m²)
- Site time: faster — 6 to 10 weeks on site (panels arrive factory-built)
- Thermal inertia: lower — requires integrated heavy layer (screed, internal masonry wall) to meet summer-comfort criteria
- Insulation: insulation sits inside the frame, reducing wall thickness vs ETICS
- Carbon footprint: 30–40 % lower embodied-carbon profile — increasingly favoured under Klimabank scoring
- Acoustic performance: requires dedicated acoustic layer between floors; baseline lower than masonry
- Energy-class A/AA compliance: reached natively with 28–32 cm integrated insulation
- Resale value: rising in LU, though valuation volatility remains higher than masonry
When timber wins:
- Steep plots where prefab minimises site disruption
- Tight build schedules
- Projects targeting passive-house certification
When masonry wins:
- Heritage-zone builds where municipal aesthetics prefer rendered masonry
- Projects where acoustic separation between rooms is critical
- Plots with easy crane and truck access where site time is secondary
A 2026 trend: hybrid builds (masonry ground floor, timber frame upper) combine masonry mass where it helps (acoustic, fire) with timber speed where it wins (roof, upper floor). Typical hybrid premium: 5–10 % over masonry-only.
TVA 3 % logement.lu — the mechanism
The 3 % super-reduced rate on a new single-family house construction in Luxembourg is the largest TVA saving available to homeowners — worth €15 000 to €30 000 on a typical build. It is not automatic.
Eligibility:
- The building must be constructed as the owner's principal residence
- The owner must be a natural person (not a corporate vehicle)
- The total VAT advantage is capped — currently €50 000 net per dwelling across its lifetime
- The mechanism covers gros œuvre, second œuvre and corps techniques for the habitable portion; it does not cover furniture, landscaping or commercial annexes
Application steps:
- Architect or notary provides the logement.lu application form
- Owner signs the principal-residence declaration
- Application filed via MyGuichet.lu BEFORE the first invoice is issued by any contractor
- AED (Administration de l'Enregistrement) reviews and issues the authorisation, typically 2 to 6 weeks
- Each contractor's invoice references the authorisation number and applies 3 %
- Running total of VAT advantage tracked in case it approaches the lifetime cap
Common pitfalls:
- Missing the pre-invoice deadline — even one invoice at 17 % before authorisation can disqualify the project
- Use of the property as rental within the first 10 years — triggers retroactive VAT reclaim by AED
- Expanding the dwelling beyond the plan submitted — additional works often require a supplementary application
- Mixed use (home office beyond a certain proportion) — partial VAT recapture possible
Savings worked example on a €260 000 gross project:
| Rate | Structure + all trades net | TVA | Delivered cost |
|---|---|---|---|
| TVA 17 % standard | €260 000 | €44 200 | €304 200 |
| TVA 3 % primary residence, approved | €260 000 | €7 800 | €267 800 |
The €36 400 delta is the reason most LU owners file the application early. Keep the authorisation number on every invoice and retain all files for 10 years — AED can audit retrospectively.
Construction calendar and timing levers
The Luxembourg framing calendar is driven by weather, concrete curing, subcontractor availability and permit timing. The full gros-œuvre phase runs 14 to 22 weeks from first excavation to weather-tight shell.
Typical shell timeline (150 m² masonry):
- Weeks 1–2: Earthworks, foundation drainage, footings
- Weeks 3–4: Slab pour and cure
- Weeks 5–10: Load-bearing walls (ground floor and upper floor)
- Weeks 11–12: Intermediate floor slabs
- Weeks 13–16: Roof structure and under-roof membrane
- Weeks 17–20: Roof covering, chimneys, external render first coat
- Weeks 21–22: Clean-up, scaffolding down, weather-tight handover
Timber-frame shells run 8 to 12 weeks total once panels are factory-built (panel manufacture: 6–10 weeks).
The seasonal levers:
- March to May start — best weather for slab and walls; shell typically weather-tight by autumn
- June to August start — strong progress but summer vacations of subcontractors can introduce 2–3 week gaps
- September start — risky for masonry (slab cure extends past frost window); viable for prefab timber
- November to February start — slab and block pours typically halted below 3 °C night temperatures; winter construction premium 5–10 %
Cost levers from timing:
- Book the gros-œuvre contract in autumn for a spring start — contractors offer 3–6 % early-commitment discount
- Align permit submission so authorisation lands in February or March — avoids paying scaffolding for months before start
- Lock in material prices — steel, concrete, timber and insulation prices can move 4–8 % year-over-year; some contracts include cost-escalation clauses that need careful reading
The three timing risks in 2026:
- Labour shortages in skilled trades can extend the shell by 3–6 weeks versus plan
- Prefab timber-panel lead times can stretch from 8 to 14 weeks in peak
- Commune permit delays in heritage zones or Commission-des-Sites cases — build a 4-week buffer between permit filing and contractor booking
How to compare three gros-œuvre tenders
Three gros-œuvre tenders in Luxembourg for the same architect file commonly diverge by 12–25 % — smaller than general-contractor spreads because the scope is more standardised, but still material.
The six checks that matter:
- Bid document parity. Each bidder must have received the same architect file (plans, sections, section-by-section material specification). A tender brief that lists "wall thickness per plan" is not enough — name the block model, mortar type and floor-slab thickness.
- Structural basis. Quote based on a signed structural engineer's calculation, not the contractor's assumption. Without a shared structural note, bidders take different safety margins and bids cannot be compared line for line.
- Contract structure. Forfait (fixed price) vs regie (cost-plus) vs mixed. Residential gros œuvre is almost always forfait; regie clauses inside a forfait contract are red flags.
- Payment schedule. 20 % on excavation start, 20 % on slab complete, 20 % on ground-floor walls complete, 20 % on roof structure complete, 15 % on weather-tight handover, 5 % withheld for 12 months as décennale trigger.
- Subcontractor disclosure. Some gros-œuvre packages include scaffolding and roofing subcontractors. Bidders should name these, with each subcontractor's Autorisation d'établissement reference.
- Cost-escalation clause. Material-price escalation over a 14-week construction is real — a cap or index clause protects both sides. Uncapped escalation clauses favour the contractor.
A clean briefing pack for three bidders:
- Architect-signed plans and elevations
- Structural engineer's calculation signed
- Material schedule — block type, concrete grade, steel grade, insulation
- Plot survey and access plan
- Target excavation start and weather-tight milestone
- TVA treatment (3 % or 17 %) and logement.lu authorisation status
- Payment schedule and withholding terms
- Required décennale cover proof
Three declared firms briefed on the same pack land within ±10 %. Spreads above 15 % usually trace to: (1) different material spec interpretation, (2) different assumed productivity, or (3) a bidder loading margin for an unclear scope. Call the cheapest to ask what they cut before picking them.
Framing a new single-family house in Luxembourg costs €95 000 to €210 000 for the structural shell, or €650 to €1 250 per m². The three rules that change the outcome most: (1) file the TVA 3 % logement.lu application before the first invoice to capture €15 000 to €30 000 in savings, (2) commission a structural engineer's calculation before the tender so three bidders price the same structural basis, and (3) choose construction method (masonry vs timber vs hybrid) against the site, schedule and post-completion performance targets rather than headline cost. Fynd.lu lists declared gros-œuvre contractors with Autorisation d'établissement, 10-year décennale cover and structural engineering partners — request three quotes on a fully-specified brief before signing any construction contract.
