Interior Architect Prices in Luxembourg in 2026: Rates, Billing Methods and Legal Framework
In Luxembourg, interior architect fees range from €80 to €150/hour (excluding VAT) for hourly billing, or from 8% to 15% of work costs for a complete mission with site supervision. For apartment interior renovation (80–120 m²), fee budgets range from €6,000 to €25,000 (excluding VAT) depending on mission scope. Three key points specific to Luxembourg: (1) interior architecture is a regulated profession — only professionals registered with OAI and holding an establishment authorisation can legally practise independently; (2) the profession is distinct from interior decoration, which is unregulated; (3) fees benefit from 3% VAT for renovation work on properties over 10 years old.
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Hourly rates for an interior architect in Luxembourg
Hourly billing is common for advisory missions, design-only assignments, or preliminary project phases. In Luxembourg, applied rates are substantially higher than neighbouring countries, due to salary levels and cabinet operating costs. The OAI reference rate for the public sector (architect with 5 years’ experience, June 2026) is €115.26/hour (excluding VAT); private cabinets are in a similar or higher range depending on positioning.
| Professional profile | Hourly rate (excl. VAT) LU 2026 | Typical assignment |
|---|---|---|
| Junior interior architect (< 5 years) | €70 – €90/h | Standard residential projects, small spaces |
| Experienced interior architect (5–10 years) | €90 – €130/h | Complete apartment/house renovation |
| Senior interior architect (> 10 years) | €130 – €180/h | Complex projects, prestige properties, bespoke layouts |
| Renowned studio / premium design | €180 – €250/h and above | Exceptional residences, hospitality, premium commercial spaces |
Ranges practised on Luxembourg market 2026. Reference OAI hourly rate (public sector): €115.26/h (excl. VAT) for Master’s architect + 5 years, published regularly by OAI/Guichet.public.lu.
Travel is generally invoiced separately: €0.40/km per the OAI reference scale for the public sector. For projects outside Luxembourg-City or in remote communes, travel costs can add €200 to €500 to a complete mission. Clarify this in the quote.
Fees as a percentage of work costs and per m²
For complete missions including site supervision, percentage-of-work-cost billing is most common. It aligns professional remuneration with actual project scope and incentivises budget control.
| Billing method | Range applied (LU) | Usage conditions |
|---|---|---|
| Percentage of work costs | 8 – 15% (excl. VAT) | Complete mission with site supervision; larger projects incur lower percentages |
| Site supervision only | 5 – 9% of work costs (excl. VAT) | When design was already completed elsewhere |
| Per m² of living space | €50 – €120/m² (excl. VAT) | Layout studies; lower range for large surfaces, higher for small surfaces or premium |
| Flat fee per room | €800 – €3,500/room (excl. VAT) | Design of an isolated room (bedroom, bathroom, kitchen) without work supervision |
| Ad-hoc advice / visit | €200 – €600 (excl. VAT) | Half-day consultation, project guidance, material shopping list |
Estimates from Luxembourg market 2026, consistent with OAI data and local cabinets.
A professional proposing significantly lower fees warrants verification: either they are an interior decorator (unregulated profession, without establishment authorisation or decennial liability), or an undeclared foreign provider. In Luxembourg, only an interior architect registered with OAI can legally practise independently and engage professional liability for works.
Budget fees by project type
Here are fee budget estimates (excluding work costs) for the most common Luxembourg projects, based on pricing ranges and typical building stock dimensions:
| Project type | Surface / context | Fees (excl. VAT) |
|---|---|---|
| Project guidance and orientation | Single visit, half-day | €200 – €600 |
| Layout study only (plans, furniture, materials) | Apartment 60 – 80 m² | €3,000 – €7,000 |
| Partial renovation (kitchen or bathroom) | 10 – 15 m², works €15,000 – €30,000 | €2,000 – €5,000 |
| Complete apartment renovation | 80 – 100 m², works €80,000 – €150,000 | €8,000 – €18,000 |
| Complete house renovation | 120 – 200 m², works €150,000 – €350,000 | €15,000 – €40,000 |
| Office / commercial space layout | 100 – 300 m² | €12,000 – €45,000 |
Estimates for Luxembourg market 2026. Fees vary depending on exact mission scope and cabinet profile.
Worked example: complete renovation of a 90 m² apartment in Kirchberg (Luxembourg-City), works estimated at €120,000 (excl. VAT). At 10% fee rate, the interior architect invoices €12,000 (excl. VAT). With 3% VAT (building over 10 years old), total including VAT is €12,360. At 17% VAT, the total would be €14,040 — a saving of €1,680 thanks to the super-reduced rate.
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Simulate my budget →Interior architecture in Luxembourg: a regulated profession
Luxembourg is one of Europe’s rare countries where interior architecture is a regulated liberal profession governed by law. This legal framework, established in the 2000s, protects the consumer but also imposes strict conditions on professionals.
Protected title by law — only OAI members may use it
In Luxembourg, only professionals registered with the Tableau of the Order of Architects and Consulting Engineers (OAI) and holding an establishment authorisation can use the title « interior architect » and practise independently (source: OAI, Law of 13 December 1989 as amended). A decorator or interior designer without OAI registration cannot legally present themselves as an interior architect in Luxembourg.
Level 6 diploma (Bac+3 minimum) mandatory
Entry to the profession requires a Level 6 diploma (bachelor’s or equivalent, minimum 3 years of higher education in interior architecture) recognised by Luxembourg authorities. Before obtaining their first establishment authorisation, interior architects must complete a 2-year professional apprenticeship under an established professional.
Decennial and biennial liability and mandatory insurance
The interior architect registered with OAI is subject to decennial and biennial liability for works they supervise, and must mandatorily contract professional liability insurance. In case of construction defect due to poor design, the professional engages liability up to 10 years after work handover.
Commercial independence obligatory by ethics code
The OAI ethics code (Grand-Ducal regulation of 17 June 1992) prohibits any commercial conflict of interest: the interior architect cannot receive commissions from suppliers or craftspeople they recommend. Their fees can only be those directly invoiced to the client.
In Luxembourg, interior decorator is unregulated: anyone can practise under this title without diploma, establishment authorisation, or mandatory decennial insurance. For a renovation project involving structural works, craftspeople coordination, or significant investment, an OAI interior architect provides legal protection and professional guarantee that a decorator cannot offer.
VAT at 3% on interior architect fees
Interior architect fees benefit from a super-reduced VAT rate of 3% (instead of normal 17%) when three conditions are met:
Residential property at least 10 years old
The property must be a residence completed at least 10 years ago (threshold lowered from 20 to 10 years as of 2026). Primary residences, secondary residences and rental properties are eligible if use is residential.
Services related to actual renovation works
Fees must relate to an actual renovation, transformation or improvement mission. A purely advisory or expert mission unrelated to real works does not automatically benefit from the reduced rate.
AED accreditation of the professional
The interior architect must be registered for VAT with the Tax and Customs Authority (AED) to invoice at the reduced 3% rate. Members of OAI practising independently are required to register. Without proper registration, 17% VAT applies.
Concrete savings: for €15,000 in fees (excl. VAT), 3% VAT represents €450, versus €2,550 at 17% — a saving of €2,100 on the fees invoice alone. For more, consult the complete 3% VAT renovation guide.
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Choosing an interior architect in Luxembourg: 4 criteria
Verify OAI registration and establishment authorisation
Consult the OAI Tableau on oai.lu to verify the professional is registered as an interior architect. Also ask to see their establishment authorisation issued by the Ministry of Economy. A cabinet without OAI registration practises illegally independently and cannot engage decennial liability.
Define mission scope precisely before any quote
Clarify from the start: is this a partial mission (design and plans only) or a complete mission (through site supervision and handover)? Site supervision typically represents 30% to 40% of total fees. Request a breakdown by phase.
Require written contract with indexed fees
Per OAI practices, fees are linked to the consumer price index / Luxembourg sliding wage scale. A well-drafted contract specifies the rate or flat amount at signature, indexing modalities, payment tranches and termination conditions (art. 23–24 OAI CTA Private).
Verify knowledge of local market: trusted craftspeople and materials
A well-anchored interior architect in Luxembourg knows reliable local craftspeople, real market timelines (including BTP collective holidays: summer 25 July–17 August 2025, winter 20 December–7 January 2026) and specific municipal administrative requirements. Ask for references of Luxembourg-executed projects.
FAQ — Frequently asked questions about interior architect prices in Luxembourg
What is the difference between interior architect and interior decorator in Luxembourg?
In Luxembourg, interior architect is a regulated profession: the title is legally protected, independent practice requires OAI registration and establishment authorisation, and the professional engages decennial liability. Interior decorator is an unregulated activity: no diploma or registration required, and liability for works is far more limited. For a project with works and craftspeople coordination, only an OAI interior architect provides complete professional guarantee.
How much does an interior architect cost to renovate an 80 m² apartment in Luxembourg?
For complete renovation of an 80 m² apartment (works estimated €70,000 to €120,000 excl. VAT), interior architect fees for a complete mission with site supervision typically represent 8% to 12% of work costs, or €5,600 to €14,400 (excl. VAT). The 3% VAT applies if the building is over 10 years old, limiting tax impact on fees.
Is an interior architect mandatory for renovation in Luxembourg?
No, interior architect is not legally mandatory for interior renovation not affecting building structure, roof or facade. Their use is strongly advised for any project exceeding €30,000 or involving multiple craftspeople. For works requiring a building permit and affecting load-bearing or external elements, it is an architect (not interior architect) who is legally required. Consult our permits and work declarations guide.
Can I engage a foreign interior architect for a Luxembourg project?
Yes, an interior architect legally established in an EU/EEA country or Switzerland may temporarily and occasionally provide services in Luxembourg without specific establishment authorisation — but remains subject to Luxembourg professional and ethics rules (source: guichet.public.lu). For recurring or long-term projects, the foreign professional must register with OAI and obtain Luxembourg establishment authorisation. Always verify professional liability insurance covers the Luxembourg market.
How are interior architect fees paid in Luxembourg?
Fees are generally paid in tranches linked to project progress: at contract signature (deposit), at preliminary project validation, at execution plan delivery, at works commencement, then during and at work end. Amounts are indexed to the consumer price index (Luxembourg sliding wage scale), per OAI practices.
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