Public procurement for the port of Antwerp awarded with the CO2 Performance Ladder


Several pilot projects are currently taking place in Belgium in which a CO2 Performance Ladder certificate yields an award advantage in the procurement. One of those projects is the renovation of the Scheldelaan in Antwerp. What role did the CO2 Performance Ladder play in that project? And what sustainability actions were taken?

Breaking up the foundation and sub-foundation, milling asphalt layers, removing tons of rubble and replacing it with new material… Thisis just a small selection of what had to be done during the maintenance work on the Scheldelaan in the port of Antwerp. A big task, complete with a tight deadline. Willemen Infra, the road construction branch of construction group Willemen and the project manager, had three months to finish the job.

Project leader Hans Hendrickx talks about the scope of Project Scheldelaan, which was carried out earlier this year: 'It s a two-lane road three kilometres long, complete with parking spaces and bicycle paths, that had to be completely renovated. Then you are quickly talking about approximately30,000 square meters of material (70 centimetres deep) that we had to remove and replace.'

First project with the CO2 Performance Ladder

In addition, sustainability was high on the agenda during the project. It was put on the market by the Roads and Traffic Agency (AWV), which used the CO2 Performance Ladder for the first time in a tender. Dirk van Troyen, road measurements engineer at the agency, explains this choice: 'A few years ago, a steering committee was set up to investigate whether the CO2 Performance Ladder can also be applied in Belgium. In 2019, the Flemish, Walloon and Brussels governments gave the green light for a pilot phase. This project is part of that.”

‘A total of twenty five pilot projects are being carried out with the CO2 Performance Ladder. Five in Brussels, ten in Flanders and ten in Wallonia', he continues. 'Project Scheldelaan is the first project with the CO2 Performance Ladder to be carried out in Flanders.'

Own interpretation

The Belgian steering committee made various agreements about the CO2 Performance Ladder. For example, companies with level 4 or 5 on the Ladder will for the time being receive the same fictitious discount as companies with a level 3 certificate. In this way, small contractors (who do not yet have any experience with the CO2 Performance Ladder) are not disadvantaged. In addition, a document was drawn up that helps contracting authorities to use the instrument.

That document is not set in stone, Van Troyen emphasizes. Contracting parties have the opportunity to set their own emphasis, he says: 'For example, at Project Scheldelaan it was decided to halve the fictitious award advantage for companies with a certificate on the Ladder. In addition, we have not set any absolute targets for CO2 reduction, because the CO2 Performance Ladder is new to everyone. But we do plan to do so in the future.”

Climate neutral construction

Of the three major contractors that registered for Project Scheldelaan (all certified at level 3 of the Ladder), Willemen Infra was chosen to get to work. The company achieved level 3 on the Ladder by mapping its CO2 footprint and linking reduction targets to it. Franky van den Berghe, sustainability manager at the company: 'We want to emit ten percent less CO2 within three years, with 2019 as the reference year and in relation to our turnover.'

Willemen Infra is already working on obtaining a certificate at level 4 or 5 of the CO2 Performance Ladder. Sustainability is high on the agenda these days, says Van den Berghe. And a higher level on the Ladder fits in well with this: “In the past, sustainability was always something we did on the side, but nowadays it is really integrated into our strategy and policy. We want to achieve maximum value throughout our business operations with as little impact on the environment as possible. The ultimate goal: climate neutral construction without negative consequences for ecosystems. There is a lot to consider. From optimal use and management of raw materials to innovative and circular construction methods.'

Green electricity and materials reuse

Several sustainable actions were also taken during Project Scheldelaan. For example, Willemen Group made the switch from green energy from Europe to green energy from Belgium, for all offices, warehouses and production facilities. 'Green electricity is considered green electricity in Belgium, regardless of its origin', says Van den Berghe. ‘But the CO2 Performance Ladder is stricter on this. We were already planning to switch to Belgian green electricity in the long run, but the Ladder enabled us to do that more quickly.'

Secondly, efforts were made to reuse material to reduce the CO2 footprint of Project Scheldelaan. Hendrickx: 'We reused about ten percent of the old surface of the road surface, by mixing it with new material and milling it in with cement. Then you are quickly talking about approximately 5,000 cubic meters (m³) of sand that we did not have to bring in and out.'

More sustainable asphalt

Thirdly, Willemen Infra focused on the use of asphalt with a reduced temperature. Asphalt is normally produced at a temperature of about 180 degrees Celsius. But by applying certain techniques, such as foaming the bitumen, a temperature of 120 degrees Celsius can also suffice. Hendrickx: 'Higher temperatures equal more energy consumption, it's as simple as that. So if you carry out the process at a lower temperature, you save energy.'

Until now, Willemen Infra did not know exactly how much energy they saved with this more environmentally friendly form of asphalt production. This was mapped out for the first time for the CO2 Performance Ladder. Van den Berghe: 'It results in about fifteen percent lower natural gas consumption in our asphalt plants.'

Lessons learned

Project Scheldelaan was an instructive experience for all parties involved with regard to the CO2 Performance Ladder. According to Hendrickx, for example, the Ladder served as a nice motivation to keep thinking about improvements. ‘You organize processes in a smarter way, combine things, you name it. The energy and material savings that you save are not only good for the environment. They also improve your competitive position. In Belgium, the competition is quite fierce, so that's a plus.'

In addition, the CO2 Performance Ladder ensured that sustainability was placed more prominently on the agenda at Willemen Groep, adds Van den Berghe. '‘The policy improved and employees became more involved. Sustainability is much more alive now. Not only at the board, but also on the work floor.’

Positive about the Ladder

According to Van Troyen, Project Scheldelaan offers a lot of perspective for the future: 'We have been very positive about the CO2 Performance Ladder so far. I think there is a good chance that it will be used on a large scale in Belgium in the future and that it will encourage contractors to take more sustainable measures.”



Project details

Contracting authority:

Roads and Traffic Agency (AWV)


Willemen Infra


± €3.000.000,-


Port of Antwerp

Project duration:

Three months

Ambition level of the winning party:

Level 3

Award advantage given:

3% on the tender price

Focus CO2 reduction on project:

Use of green energy at the asphalt plant, use of asphalt produced at lower temperature, reuse of materials.