FAQ

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You can also e-mail us. For questions about administration, finances or login details, please email administratie@skao.nl. For other questions, please email info@skao.nl. We will do our best to reply to you as soon as possible.

Industry organisations and clients have consulted together in the Central College of Experts (CCvD) on the content of the new standard. The representatives consulted regularly with their constituencies on each proposed change. CO₂ Performance Ladder version 4.0 was thus – like previous versions – developed together with the market.

Step 1 of CO₂ Performance Ladder version 4.0 is similar to level 3 of CO₂ Performance Ladder version 3.1. An organisation starts working on short-term targets (up to 3 years) and its own organisation’s energy consumption and emissions (scope 1 and scope 2).

Step 2 of CO₂ Performance Ladder 4.0, like level 5 of CO₂ Performance Ladder version 3.1, focuses on an organisation’s value chain (scope 3). The focus is on an organisation’s main activities and on the medium term (5 to 10 years).  

Step 3 goes further than any level of CO₂ Performance Ladder version 3.1. The emphasis is on the long-term goal (up to 2050) of zero emissions, both for its own activities (scope 1 and 2) and for the chain (scope 3). An organisation is also encouraged to look beyond the chain to emissions outside the scopes, such as avoided emissions or emissions from biomass combustion.

From 14 July 2025, six months after publication of the new standard, you as an organisation can obtain a certificate for CO₂ Performance Ladder version 4.0. However, you can already orientate yourself to version 4.0 in the first six months and think about what the changes mean for your organisation. You can already view the requirements of version 4.0 via My CO₂ Performance Ladder. Read more about the validity of the different versions of the CO₂ Performance Ladder here.

Want to know more? Register for our live online event: Discover CO₂ Performance Ladder 4.0: Towards zero emissions. 

No later than your first audit after 14 January 2027, you must make the final switch. Until that date, you can still opt for a (re)assessment on CO₂ Performance Ladder version 3.1 during an audit.

As many certificate holders are unlikely to have switched over by 2025 and 2026, we ask contracting authorities not to start using version 4.0 in tenders until 2026 at the earliest. The most important thing is that the market is really ready; if in doubt, we recommend waiting until 14 January 2027. From 14 January 2027, we advise contracting authorities not to use Manual 3.1 in tenders.

In the transition period from CO₂ Performance Ladder version 3.1 to CO₂ Performance Ladder 4.0, 4.0 certificates can be accepted in a tender based on Manual 3.1. For example, step 1 in Handbook 4.0 is equivalent to level 3 in Handbook 3.

No, a certificate for version 3.1 is not valid in a tender based on version 4.0. This is because version 4.0 goes beyond version 3.1 in many cases.

Because you implement a CO₂ management system with the CO₂ Performance Ladder, your organisation can fall back on this again and again as a foundation for the annual CSRD sustainability report. CSRD was taken into account during the development of CO₂ Performance Ladder 4.0. As far as possible, CO₂ Performance Ladder 4.0 uses the same preconditions as CSRD to avoid duplication of effort.

Read more about the relationship between the CO₂ Performance Ladder and CSRD here. 

The Environmental Cost Indicator (EQI) can serve as a CO₂ footprint for projects, provided the CO₂ component is specifically named. This avoids double calculations and keeps the focus on CO₂ reduction.

The CO₂ Performance Ladder is an instrument that helps companies reduce CO₂. The instrument is used by clients and contractors for tenders. The principle of the Ladder is that efforts are rewarded with a concrete advantage in the tendering process in the form of a discount on the registration price. Read more about what the CO₂ Performance Ladder is exactly.

The CO₂ Performance Ladder is a CO₂ management system. A management system is a coherent set of agreements and working methods and an organisational structure for the planned and systematic control and improvement of business processes in order to achieve set objectives. Other well-known management systems include ISO 9001 (quality management system), ISO 14001 (environmental management system) and ISO 50001 (energy management system). All management systems sense continuous improvement and have a PCDA (Plan Do Check Act) cycle.

The CO₂ Performance Ladder (both version 3.1 and version 4.0) has been accepted in the Netherlands by the Dutch Accreditation Council (RvA) and in Belgium by BELAC as an accredited certification system in accordance with NEN-EN-ISO-IES 17021-1, certification of management systems. The RvA acceptance for this scheme is known as S571. The Accreditation Council and BELAC accredit Certifying Bodies. These organisations guarantee expert, impartial and independent supervision of the assessment of Certifying Bodies.

Certifying Bodies that comply with the standard (CO₂ Performance Ladder) receive formal accreditation. This means that they are allowed to use the accreditation mark. Certificates and reports bearing this mark are accepted in almost all countries worldwide.

The Foundation for Climate Friendly Procurement and Business (SKAO) is the owner and manager of the CO₂ Performance Ladder. Read more about the foundation.

The University of Utrecht has conducted scientific research into the CO₂ emissions of companies certified for the CO₂ Performance Ladder. In the companies surveyed, the CO₂ reduction from 2010 to 2013 was 3.2 percent per year. This while the average energy saving rate in the Netherlands is 1.5 percent per year. Companies with a certificate therefore reduce twice as much CO₂.

• CO₂ reduction and energy saving: you reduce your energy consumption and actively contribute to the reduction of CO₂ emissions.
• Award advantage: you benefit from CO₂-related award advantage in tenders, giving you a better chance of winning tenders.
• Lower costs: the energy you save also reduces your energy bill. Innovative measures you take can also be cost-saving in the longer term.
• You use an internationally recognised management system.

There are more than 8,000 organisations certified on the CO₂ Performance Ladder, and more than 300 contracting authorities use the Ladder in tenders. For an overview of these certified organisations, see the Participants page.

You can register your organisation for the CO₂ Performance Ladder via this link. Here you fill in your personal details and organisation data. After receipt of your payment, we will send you login details that will give you access to My CO₂ Performance Ladder. In this online environment, you can upload the files required for certification.

An organisation seeking certification for the CO₂ Performance Ladder must meet the requirements of the Ladder. An external auditor checks if this is the case. The requirements of the CO₂ Performance Ladder are set out in our standard and consist of a general part, which all organisations must meet, and a part that deals specifically with the ambition level you choose as an organisation. If you choose level 3, for example, you will therefore have to meet the general requirements and the requirements specifically about level 3. Read more about Certification for the CO₂ Performance Ladder here.

For the time being, organisations can only obtain a certificate for version 3.1 of the CO₂ Performance Ladder. You can read about the requirements of version 3.1 in our CO₂ Performance Ladder 3.1 handbook.

However, you can already view the requirements of version 4.0 via My CO₂ Performance Ladder. Read more about the validity of the different versions of the CO₂ Performance Ladder here.

On the Documents webpage there are several Practical Guides that you can consult as an aid when certifying for CO₂ Performance Ladder 3.1.

For version 4.0 of the CO₂ Performance Ladder, we have developed a digital environment in which you can consult the requirements in a conveniently arranged manner and to which additional explanations and examples have been added at relevant points. We are continuously adding content to help you on your way.

In addition, we have developed a list of measures that you can consult for inspiration and you can also view the publications of other organisations for inspiration for your own publications.

Yes, small organisations can certify and are eligible for certain exemptions depending on their size and turnover.

SKAO has drawn up a list of all Certifying Bodies (CBs) that may conduct an audit for the CO₂ Performance Ladder. Only these parties have been authorised by SKAO to issue a CO₂ awareness certificate. All these CBs are accredited by the Accreditation Council or BELAC.

An initial audit is followed by annual audits and a recertification audit every three years.

To determine the duration of an audit, SKAO has published the audit day table. This document gives Certifying Bodies (CBs) a guideline for the minimum time required for an audit at an organisation. This expected time commitment depends on a number of factors including the size of the organisation to be certified and the (desired) ladder level. The audit day table should ensure that the Certifying Institution has sufficient time to perform a proper assessment and thus ensure the quality of Ladder assessments.

There are more than 8000 organisations with a certificate for the CO₂ Performance Ladder, and more than 300 contracting authorities use the CO₂ Performance Ladder in tenders. These include parties from the national government, municipalities, water boards and provinces. For an overview of these contracting authorities, see the page commissioning parties.

Yes! The CO₂ Performance Ladder is part of the Dutch Guide to Socially Responsible Procurement (SRI). For more information please have a look at the website of Pianoo.

The CO₂ Peformance Ladder as a tendering instrument consists of a BPKV criterion CO₂ Peformance Ladder that can serve as the basis for an award advantage in a tender. Procurement Guide 3.1 describes how this criterion can be used. This guide also contains the text of the criterion. Read more on the procurement page with the CO₂ Performance Ladder.

The CO₂ Performance Ladder is not suitable as an eligibility requirement or selection criterion.

There are several reasons for this:

– Implementing the CO₂ Performance Ladder within an organisation takes time and effort. In most situations, it will be disproportionate to require an organisation, prior to tendering for a specific project, to certify the entire organisation. Such a requirement is not reasonable for a project that will constitute only a (small) part of the organisation’s turnover. From a procurement law perspective, there is then insufficient connection between the requirement and the subject matter of the contract. Also for this reason, such a requirement is not allowed as a suitability criterion or selection criterion.

– Using a certificate as an eligibility criterion or selection criterion means that parties without the required (level of the) certificate cannot compete or have less chance of being selected. This discriminates against foreign parties or small companies, for example. Procurement law does not allow this.

This principle applies to all tenders: European, national, and private treaty. For small contracts, such a suitability requirement is just as discriminatory. For private contracts, no further selection takes place anyway.

Each CO₂ Performance ambition level has an award advantage. As the client, you determine the award advantage per level. Most clients work with percentages, but it is also possible to work with fixed amounts or points.

The level of the award advantage and the way in which it is calculated should be described in the customer’s tender documents, so that it is clear how this advantage relates to the scoring of other qualitative elements (PPP criteria) of the tender, see Procurement Guide 3.1.

Organisations bidding for a tender that includes the BPKV criterion CO₂ Performance Ladder can meet this criterion in two different ways. In both cases, the organisation must demonstrate within one year of being awarded the contract and then annually, during the life of the project, that it complies with the BPKV criterion CO₂ Performance Ladder:

– By submitting a CO₂-aware Certificate at the chosen ambition level. With this, the tenderer demonstrates that it meets the requirements of the Ladder, including during project execution.

– By complying specifically with the requirements of the BPKV criterion at the chosen ambition level and submitting a project statement to that effect.

See Procurement Guide 3.1.

If compliance with the BPKV criterion is demonstrated with the CO₂-aware Certificate, the certified company has a working CO₂ management system that is audited annually. This audit not only looks at the objectives and measures at company level, but also randomly examines the projects with a CO₂ Performance Ladder award advantage that a company carries out. The audit is carried out annually by an independent Certifying Body (CI).

If meeting the BPKV criterion is demonstrated project-specifically, a company must implement reduction measures on the project and a CB examines whether these measures are actually implemented and draws up a project statement on this.

You can register your organisation here to get started with the certification.

1. As a certificate holder, you pay an annual contribution to SKAO. See our rates. The rate applicable to your organisation depends on the size or turnover of your organisation.

2. You also pay costs to the certification body (CI) that carries out the audit of your organisation. These costs also depend on your organisation’s size, level of ambition and so on. Ask the CB of your choice for its rates. See this page for all CBs.

3. Some organisations choose to use a consultancy firm to support the certification process. This is not a requirement for the implementation of the CO₂ Performance Ladder. However, a consultant can assist and help you on your way. There are also costs associated with this.

• Upon initial registration, your organisation will immediately receive an invoice for the rest of the year. Only after payment will you receive login details.  
• After that, invoicing takes place annually in April.  
• One month in advance, your organisation will receive an advance notice for invoicing, with a request to check the data known to us.  

• After you have paid the invoice, our colleague must manually set it to paid in our database. This is done on Monday and you will receive the login details on this.
• It is therefore possible that you have paid, but that our colleague has not yet processed it. Please wait until the following Monday.

• Please note: do not re-register the organisation. 
• The current CO₂ manager can modify the company and contact details himself, i.e. also add a new contact person. This can be done in the login environment. 
• Are you the new CO₂ manager and need to change it? Then we will be happy to help you with this. If so, please send your details and the request to administratie@SKAO.nl.  

You can change your password yourself. Click on ‘Request new password’ on the login page. Would you prefer help with this? If so, call us and the new password will be passed on by phone.

Your organisation will not be published on the SKAO website until the CO₂-aware Certificate is obtained. Your LadderCI will forward the certificate to SKAO, you do not need to do anything else. If you are unsure whether your CB has forwarded the certificate to us, please check with your CB. If the certificate has been sent to us but you are not listed on the website, please notify SKAO via certificaat@skao.nl.

‘Scopes’ in the Greenhouse Gas Protocol indicate categories for different sources of CO₂ emissions. Scope 1 is direct emissions from combustion within the company, such as gas consumption or fuel for machinery. Scope 2 includes indirect emissions from electricity consumption generated elsewhere. Scope 3 is chain-wide emissions and includes emissions from purchased goods to transport and downstream use by customers. Scope 3 is broad and includes all chain-related emissions that cannot be directly related to the own company.

The definition of green electricity according to the CO₂ Performance Ladder is electricity generated by sun, wind, water or biomass and produced in the same country where it is used. Read more about green electricity according to the CO₂ Performance Ladder here.