What the architect owes the budget
In Luxembourg, the budget is not merely the client's wish: it is a limit set by the rules of professional conduct. The Grand-Ducal Regulation of 17 June 1992 laying down the code of conduct for architects and consulting engineers (règlement grand-ducal déterminant la déontologie des architectes et des ingénieurs-conseils) requires a written agreement signed by both parties, at the latest once the assignment has been defined (art. 8). Its article 9 states that the architect and the consulting engineer "shall take care to submit designs that remain within the limits of the brief set in the assignment and of the budget arising from it, in accordance with the agreement concluded between the parties" (unofficial translation).
The same article organises change. Any significant change to the brief, during design or construction, "must be the subject of an additional agreement stating its financial impact". Article 13 adds that the architect assists the maître de l'ouvrage (the client, in the wording of the regulation) in choosing the parties involved "with a view to carrying out the project on the best terms of price and quality".
The practical consequence: each estimate is read against two written references, the budget in the agreement and the latest additional agreement. Without these documents, there is nothing to compare the estimate with.
Independent does not mean accurate
The architect has no interest in the price of the works. Articles 4 and 5 of the 1992 regulation make independent practice "always incompatible with the profession of contractor for any construction works", directly or through an intermediary. That guarantees independence.
It is not a guarantee of accuracy. An estimate rests on quantities measured from drawings that are still incomplete and on assumed prices. The person who designs the project is also the person who prices it: optimism bias is possible without any bad faith. The client's check is therefore not a sign of mistrust; it is a method.
Three checks at each phase
A useful check does not look at every unit rate, but at comparability. Three questions are enough to catch most drift.
| Check | Question to ask | Warning sign |
|---|---|---|
| Same basis | does the estimate cover the same scope as the budget (works only or total cost, excluding VAT or including VAT)? | a total "going down" that has lost the external works, the fees or the VAT |
| Same price date | at what date are the prices expressed? | two estimates with no date, or a date still left at the sketch design stage |
| Same items | does every item in the previous estimate reappear, at the same level of detail? | an item that has vanished without explanation, a contingency absorbed into the prices |
Reading an estimate item by item means knowing how it is built: the method is described in the article on building an item-by-item estimate. Just before tendering, the check moves to the priced schedule, as set out in the article on checking a schedule before tendering.
When the estimate becomes the devis
In a public contract, the last estimate changes status. Here the devis means the estimate drawn up by the contracting authority (pouvoir adjudicateur), not a contractor's tender: the Law of 8 April 2018 on public procurement refers to it when choosing the procedure (art. 19) and for the final account (art. 47), and the implementing Grand-Ducal Regulation prohibits disclosing it to tenderers (art. 45 (5)).
An estimating error at this stage therefore has three effects: it can point towards an unsuitable procedure, it distorts the reading of the tenders, and it will remain the reference for the final account. The subject is covered in the article on the contracting authority's estimate.
What remains with the client
Checking also means leaving a record. At each phase, a written response to the estimate (accepted, accepted with reservations, rejected) sets the reference for the next phase. If the gap stems from a change the client requested, the article 9 additional agreement must cost it; if it stems from the design, the architect proposes how to return within budget.
The articles in this branch
- The article on the architect exceeding the budget covers what the client can do when the design exceeds the budget in the agreement, and the evidence that helps.
- The article on an estimate that exceeds the budget before tendering covers the levers to pull while the tenders are not yet open; it is supplemented by a method for preparing the trade-off note.
- The article on the independent counter-estimate covers when a second estimate is justified, what is compared and its limits.
- The article on the contracting authority's estimate in a public contract covers the estimated value, the procedure thresholds it determines and its confidentiality.
This article sets out the rules as they stood on the date of verification and is intended as professional guidance. It does not replace legal advice or an examination of the specific case.