Flag the measurement error and you pocket the price advantage — stay silent and lose by €892: why the quiet bidder comes off worst
The Council of State rejects the extreme-urgency action against the award of the new Ter Caele care home in Evergem: the winning bidder was the only one to flag an inflated quantity in the summary bill of quantities (100 instead of 45 units), rightly received the downward price advantage that article 86 of the Procurement Placement Decree reserves for the flagging bidder, and thereby won by a mere €892 — while the losing bidder argued in vain that this was a 'purely material error' that should have been corrected equally for everyone.
What happened?
The Meetjesland Care Company launched, via an open procedure, a works contract for the new 'Ter Caele' care home at Hoeksken in Evergem (shell, finishing and technical works), with price as the sole award criterion. Ten bidders submitted regular bids. The opening report showed the two lowest amounts from the winning bidder (nv W., €15,080,433.29) and the applicant (nv A., €15,185,486.80) — a gap of over €105,000. In the arithmetic check of 16 March 2026, the appointed architectural firm made one decisive observation: only the winning bidder had signalled that item 54.08.11.01 ('fire-door magnet — surface-mounted wall') showed a lump-sum quantity of 100 units in the summary bill, whereas the plans and the detailed measurement only required 45. The winning bidder proposed 46 units with a justification note and its own calculations; after checking, the architect accepted 45. Under article 86, § 4, second paragraph of the Placement Decree, such a downward correction is credited solely in favour of the bidder who flagged it. As a result the gap between the two bids shrank to a mere €892.03, and the contract went to the winning bidder on 24 March 2026 (ranking amount €15,105,153.68 excl. VAT). The applicant went to the Council of State under extreme urgency with a single ground in three parts. The core of its case: because the detailed measurement already stated the correct 45 units, the error in the summary bill was not a 'quantity correction' under articles 79 and 86 (which benefits only the flagging bidder), but a 'purely material error' under article 34, § 1, which the authority should have corrected equally in all bids — so that the ranking advantage should not have gone to the winner. In the alternative, it considered the specification clause linking the correction to the detailed measurement unlawful, and, more subsidiarily, alleged a breach of the duties of care and equal treatment. The Council follows none of the three parts. The purpose of articles 79 and 86 — as the report to the King shows — is precisely to encourage bidders to flag reductions in quantities: whoever does so also bears alone the execution risk of that reduction at a lump-sum price. The starting point for the check, under article 79, § 1, is the summary bill of quantities, which the bidder fills in and which determines the bid price; the fact that the specifications refer to the detailed measurement for the justification note does not turn this into an absolute condition that the error also had to appear in the detailed measurement. The winning bidder did exactly what article 79 and the specifications required. That the authority then chose the route of articles 79 and 86 rather than article 34 falls within its discretionary margin; article 80 of the Placement Decree, moreover, expressly recognises that a discrepancy between contract documents (with plans prevailing over the specifications and the specifications over the summary bill) may justify a correction. The specification clause making the detailed bill binding in the execution phase belongs to the 'Provisions under the Execution Decree' and governs execution, not placement. There was no carelessness or unequal treatment either: correcting errors is precisely what the rules allow and pursue, and the applicant could just as well have checked and flagged the quantity itself. The difference in treatment flowed directly from the specifications and articles 79 and 86. The single ground was found not serious and the action rejected. The applicant was ordered to pay costs (court fee €200, contribution €26, procedural indemnity €770), the intervening party a court fee of €150.
Why does this matter?
For contractors and bid managers on works contracts with a bill of quantities, this arrest is a costly reminder: checking quantities is not a formality, it is money. A bidder who spots an inflated lump-sum quantity and flags it downward by the rules (article 79, with a justification note) receives, under article 86, § 4, the sole ranking advantage — an advantage that can decide between winning and losing. A bidder who stays silent, assuming such a discrepancy is a 'purely material error' the authority will correct for everyone alike, bets wrong: the Council confirms that the authority may opt for the article 79/86 route, and that the summary bill is the benchmark — not the detailed measurement. The loser here trailed by €892, precisely because the competitor flagged it and it did not.
The lesson
Treat the summary bill of quantities as the document on which you win or lose money. Recompute every lump-sum quantity against the plans and the detailed measurement. If you find a quantity that is too high, flag it before submission with a justification note under article 79 — reproduce the detailed measurement and point line by line to where the error lies. Do not rely on a 'material error' that the authority will spontaneously correct for all bidders: for a reduction, the advantage under article 86, § 4 plays only for the one who flagged it. And do not forget the flip side: whoever flags a reduction then performs that item at a lump-sum price and bears the risk of an underestimate.
Ask yourself
Take your last bid for a works contract with a bill of quantities. Did you recompute every lump-sum item against the plans and the detailed measurement? Is there an item where the stated quantity is clearly too high? If so: did you flag that reduction with a justification note reproducing the detailed measurement and pointing line by line to the error — or did you assume the authority would correct it? In the second case you leave on the table a ranking advantage that a competitor will claim.
About this database
The Council of State (Raad van State / Conseil d'État) is Belgium's supreme administrative court. In disputes over public procurement — from contract awards to tenderer exclusions — the Council of State is the final arbiter. The rulings in this database are summarised by TenderWolf in plain language, with practical lessons for tenderers and contracting authorities. View all rulings →