Tender advantage on the CO₂ Performance Ladder: how gunningvoordeel works and what it is worth

What is gunningvoordeel?

In a public tender the CO₂ Performance Ladder (CO₂-Prestatieladder) acts as an award criterion, a gunningscriterium. The authority awards on best price quality ratio, treats your CO₂ ambition level as quality, and converts that quality into money or points. The Dutch term for the money version is fictieve korting, a notional discount.

All three share one property: the discount is notional. It exists only during evaluation. If you win, you are paid the price you tendered.

SKAO, the scheme owner, writes on its procurement page that the Ladder has been used in more than 5,000 tenders, and addresses more than 300 contracting authorities as users.

How is the advantage calculated?

The arithmetic is plain. The example below uses the Rijkswaterstaat method that has applied since 1 July 2026.

Bidder A was a million euros more expensive and still wins. And receives the full thirty million. That is the entire commercial logic of the instrument in one table.

Watch one detail in the tender documents. The spread across the steps does not have to be even. The Handreiking Aanbesteden 4.0, SKAO's procurement guidance, states that the distribution of those values need not be linear and that higher ambition levels, for example 2 and 3, may be given proportionally greater advantage.

How much advantage do you get per step?

There is no national tariff. SKAO publishes an illustrative model and says so explicitly: "Welk percentage, bedrag of puntenaantal u als gunningsvoordeel kiest, bepaalt u zelf." You decide the percentage, amount or number of points yourself.

Source: SKAO, procurement with version 4.0.

This is a worked example from SKAO's own publication. It is neither a standard nor a tariff. Rijkswaterstaat sits well below it at 2, 4 and 6 percent. Treat the SKAO table as the upper bound of what you might meet somewhere.

What changed at Rijkswaterstaat on 1 July 2026?

Rijkswaterstaat, the Dutch national roads and waterways authority, has applied Handbook 4.0 since 1 July 2026 in tenders for grond-, weg- en waterbouw (GWW): earthworks, roads and hydraulic works. ProRail, the national rail infrastructure manager, follows on 1 January 2027. No switching date has been announced for other categories of contract. That gap between civil engineering and everything else is exactly what suppliers of services, IT, healthcare and logistics run into, which we work out in the CO₂ Performance Ladder outside construction.

Rijkswaterstaat states the figures flat: "trede 1 leidt tot een fictieve verlaging van de inschrijfsom met 2 procent, trede 2 met 4 procent en trede 3 met 6 procent." Trade title Infrasite describes step 3 as a maximum of 6 percent. We follow the wording of the authority itself and flag the difference here, so you can check it against the tender documents.

Two points for your tender planning. Handbook 4.0 applies only to tenders published on TenderNed after 1 July 2026; earlier publications continue under 3.1, where a 4.0 certificate may be submitted and is assessed against the 3.1 levels. And after award, in Rijkswaterstaat's words, contractors have "maximaal 1 jaar de tijd om het certificaat voor de aangeboden trede aan te tonen", at most one year to evidence the certificate for the step they offered.

The percentage is lower than in the SKAO model while the bar is higher. Step 2 requires scope 3 plus a climate transition plan, considerably more work than the old Niveau 3, which was the de facto market baseline. See why there are now three steps, not five levels.

What does ProRail do, and why is there no percentage here?

ProRail has used the Ladder since 1 December 2010 and applies a notional discount on the bid price that rises with the ambition level offered: "Hoe hoger het ambitieniveau, hoe hoger de fictieve korting op de inschrijfprijs." From 1 January 2027 ProRail intends to use Handbook 4.0 in new tenders.

We publish no per level percentages for ProRail. Public sources contradict each other on the range and on the number of bands, and ProRail says so itself: its tender documents on TenderNed are what govern. Read the document for the live tender.

Watch the vocabulary in the tender documents too. If it says "niveau" (level), you are reading a 3.1 tender. If it says "trede" (step), it is 4.0. That determines which evidence you are allowed to submit. Practitioners describe auditors who react allergically when you use the wrong one of the two.

Which other contracting authorities use the Ladder?

Belgium has roughly 100 certificates covering more than 300 enterprises. The Flemish policy domain for Mobility and Public Works wrote: "Wij zullen vanaf 1 januari 2025 de Ladder meenemen in bestekken voor infrawerken vanaf vijf miljoen euro." It includes the Ladder in specifications for infrastructure works from five million euros. Within that same policy domain, OVAM, Agentschap Wegen en Verkeer and De Vlaamse Waterweg are among the authorities committed to the Ladder.

In Wallonia the government decided on 3 June 2026 that SPW Mobilité et Infrastructures and SOFICO will include CO₂ criteria from 1 January 2027, with a notional discount of 6 percent for échelon 1 and 10 percent for échelon 2, from 600,000 euros upward. Note the source conflict: SKAO's own article on Belgium is from 22 April 2024 and still reports that Wallonia has decided nothing. More in what Flanders has required since 2025.

The Ladder also works below the European threshold amounts. SKAO writes in its FAQ that you can use it as an award criterion below the threshold, and that in a multiple private procedure you can ask bidders for their CO₂ ambition level. The Handreiking itself is written around directives 2014/24/EU and 2014/25/EU.

Do you need to be certified to bid?

No. This is the most persistent misunderstanding in the market. The Handreiking is explicit: "De inschrijver hoeft bij inschrijving nog geen projectverklaring of CO₂-Prestatieladdercertificaat te overleggen." No project declaration and no certificate at the moment of tendering.

You declare which CO₂ ambition level you are bidding at, and that level is fixed contractually. Within one year of award you have to demonstrate that you reach it, then repeat that annually for the duration of the project. There are two forms of evidence:

• a CO₂-bewust certificaat, the CO₂ aware certificate, at the step you offered, valid three years with annual surveillance audits, usable across all your projects and clients;
• a projectverklaring, a project declaration for that one project, which per the Handreiking is "afgegeven is door een CI die geaccrediteerd is voor het certificeringsschema CO2-Prestatieladder", issued by a certification body accredited for the Ladder scheme.

Watch which legal entity the certificate names: it has to cover the entity that submits the bid. In a group the CO₂ data usually sits on business units that work for more than one legal entity. Any allocation key then falls back on revenue or cost, and that shifts every year. The full treatment is in organisational boundaries across multiple entities.

Can an authority make the certificate a selection requirement?

No. A certificate may not be a geschiktheidseis, a suitability or selection requirement.

SKAO's reasoning: "Als u een certificaat hanteert als geschiktheidseis of selectiecriterium, dan kunnen partijen zonder het gevraagde (niveau van het) certificaat niet meedoen." Parties without the requested certificate level cannot take part at all. That conflicts with non discrimination, with proportionality, and with the requirement that a criterion is linked to the subject matter of the contract. If you meet tender documents that impose it as a selection requirement, you have concrete grounds for a clarification question.

What happens if you do not reach the step you offered?

A contractual penalty follows. The Handreiking advises a penalty larger than the advantage enjoyed at tender: "Advies is een sanctie op te nemen die groter is dan het bij inschrijving genoten gunningsvoordeel." The recommended rule multiplies the difference by a factor, "bijvoorbeeld 1,5", for example 1.5.

The exact formula sits in your contract. Read it before you offer a step you do not yet hold.

Also count the calendar. You have a year, but that year contains a single audit moment: typically around three days, once a year, with little room to rehearse with the auditor beforehand. Win in June and plan to use the summer, and you run into the construction holiday; across the Benelux, preparation stalls between mid July and the end of August. Count your year back from the audit date the certification body gives you.

How does the advantage work in a consortium?

The weakest link decides. In the words of the Handreiking: "de organisatie met de laagste trede op de CO₂-Prestatieladder, van alle organisaties in de combinatie, bepaalt het CO2-Ambitieniveau." The organisation with the lowest step, across all organisations in the combination, sets the CO₂ ambition level.

Read that rule carefully. It is about steps. Since nobody has to produce a certificate at tender stage, an uncertified partner does not automatically pull the consortium to zero. What decides is the lowest step any participant can declare and evidence within the year after award.

That makes the offered ambition level a topic for partner selection. If a consortium bidding to Rijkswaterstaat drops from step 2 to step 1 on a thirty million euro work, that is €600,000 of notional discount gone, 4 percent against 2 percent. Take that into the conversation about how the work is shared.

Is a 3.1 certificate still valid in a 4.0 tender?

No. The other way round it is.

The transition arrangement puts it this way: "Handboek 4.0-Trede 1 wordt geaccepteerd als Handboek 3.1 Niveau 3" and "Handboek 4.0-Trede 2 wordt geaccepteerd als Handboek 3.1 Niveau 5".

SKAO's own pages word this differently, which matters because you fall back on it when reading tender documents. The FAQ places steps 2 and 3 alongside Niveaus 4 and 5. The procurement blog equates step 1 with Niveau 3 and step 2 or 3 with Niveau 5. For step 1 all three come to the same thing. The old Niveau 4 has no unambiguous successor: the transition arrangement does not mention it, while the FAQ folds it in under steps 2 and 3. If you hold Niveau 4, check per tender what the documents accept.

The commercial conclusion is narrower than it is usually stated. Migrating late does not exclude you from a 4.0 tender. You may bid and declare a step without holding a certificate. What you lack is valid evidence: a 3.1 certificate does not demonstrate that step. So you carry the risk of having to certify against 4.0 within the year after award, on an audit calendar you do not control. The last possible 3.1 audit is 14 January 2027. Migrating early costs you nothing in tender eligibility, because a 4.0 certificate also counts in a 3.1 tender. See what you can reuse and what you have to rewrite.

What is the advantage worth against the cost?

Per SKAO's own cost page the annual SKAO contribution runs from €190 (turnover under five million euros) to €6,000, with a group ceiling of €6,000. On top of that comes the certification body, roughly €3,000 to €4,000 initially and then €1,500 to €2,500 a year, plus 100 to 200 working hours of implementation.

Four percent notional discount on a single thirty million euro work is €1,200,000 of competitive position. The advantage scales with contract value; the cost of the certificate stays roughly flat. That moves the question to two others: at what contract value and tender frequency does the step you offer pay for itself, and can you evidence that step within the year after award. The figures by organisation size are in what the CO₂ Performance Ladder costs in 2026.

What we see going wrong in practice

Two patterns keep coming back in working sessions with sustainability and tender teams.

You are ready for the wrong audit. One practitioner's phrasing sums it up: "We are ready to do the audit following the 3.1 handbook, but we do not have the new demands in the handbook." Most of the work carries over to 4.0. What does not carry over stays invisible until you go looking for it. There are no sector templates yet and few contractors have gone ahead of you.

The evidence is not attached to the number. The best definition of audit ready we have heard comes from a practitioner: if you have the disclosure, all the evidence locked to that exact data point, and the text showing where the number came from, you have already won the discussion with the auditor beforehand. On a tender advantage above a million euros, that is a risk you do not have to run.

How Palau handles this

With tender advantage the discussion is rarely about the arithmetic. The question is whether the entity that submitted the bid can evidence the step it offered within the year. Palau's Organisational structure module holds the consolidation across legal entities, business units and locations, so you can report per certifying entity without losing the group data. Vault locks every piece of evidence to the data point it belongs to, with traceability down to the page and sentence the number came from. See also our CO₂ Performance Ladder page.

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