Published: 29 March 2023

The CO2 Performance Ladder as start of a sustainable adventure

Bastina van Houwelingen

De Vries Stolwijk


In recent years, construction contractor De Vries Stolwijk B.V. has made great strides in the area of sustainability. That sustainable adventure started with certification on the CO2 Performance Ladder. “It was initially about the fictitious award advantage for us,” says KAM (Quality, Working Conditions and Environment) coordinator Bastina van Houwelingen. “But once you start working with the Ladder, you soon notice that more is possible.”

De Vries Stolwijk is a South Holland-based construction company, mainly active in ground, road and hydraulic engineering. The small enterprise, consisting of 25 internal and external employees, specialises in (among other things) bank protection, sewer construction and the redevelopment of residential areas and nature reserves.

Straight to level 5

Sustainability came on the agenda at De Vries Stolwijk around 2015, says Van Houwelingen: “We noticed that the CO2 Performance Ladder was increasingly being asked for in the market and that it would become the tendering instrument of the future. So we decided to get certified as well. Initially, the fictitious award advantage was our main motivation, to be just that one step ahead of our competitors.”

De Vries Stolwijk also decided to obtain Level 5 certification right away. Either we really dive in or we don’t do it at all, was the reasoning. “When you start at level 3, you don’t immediately reap all the benefits of a certificate on the Ladder,” explains Van Houwelingen. “And you have to go back to work at a later stage, to achieve a higher level. It therefore seemed smarter to us to go for level 5 right away.”

Solar panels and LED lighting

Since then, De Vries Stolwijk has taken several steps to make its own operations more sustainable. Especially in the initial phase, it was able to immediately realise good CO2 reductions, for instance by switching completely to green electricity and installing 98 solar panels on the roof of the office. In addition, old lighting was replaced by LED lighting and motion sensors were installed so that the lights are only on when employees are present.

Until 2024, De Vries Stolwijk will further reduce its CO2 emissions by at least 3 per cent. All hired excavators must be Tier 3b or higher by the same year. “And we are exploring the possibilities of purchasing hybrid or fully electric machines in the future. Right now, for example, we are in the process of purchasing an electric vibratory plate and rammer,” Van Houwelingen adds.

Continuing to reduce CO2

So, nice steps and plans. But it is becoming increasingly difficult to keep reducing CO2 year after year, Van Houwelingen notes. Especially as an SME, whose time and resources are simply limited. “In the beginning, you take big and relatively easy steps, but that becomes increasingly challenging. How can you keep improving and reducing, even if you don’t (yet) have the financial resources for electric equipment?”

That is a matter of continually looking critically at one’s own operations, she argues. But cooperation with industry peers can also help. This is where the CO2 Performance Ladder helps; as it obliges companies to share and disseminate knowledge to the rest of the sector. “We have therefore joined the sector initiative ‘Focus on CO2’ of Cumela (the trade association for the green, soil and infrastructure sector) and attend a regional meeting three times a year with like-minded people from the sector,” says Van Houwelingen. “There we can talk to colleagues about the sustainability challenges that come our way.”

“We really learn from each other and that in turn helps us take steps in our own operations and decision-making”

Saving on fuel

Incidentally, that is not the only advantage the CO2 Performance Ladder offers De Vries Stolwijk. For instance, certification on the Ladder also made Van Houwelingen actively monitor fuel consumption. She can now see exactly which machine uses how much fuel and for which operations. “That insight allows us to target fuel reduction. That gives us (especially in these times) a lot of financial benefits. Every litre you can save is a nice bonus.”

Challenges for SMEs

But the CO2 Performance Ladder also brings challenges, says Van Houwelingen. Especially for smaller companies. “At level 5, you also have to make your supply chain transparent. At first, this can be quite difficult to fathom and involves quite a bit of administrative work,” Van Houwelingen says. She therefore advises other SMEs to hire an external consultant (especially in the first few years) to help them get to grips with the Ladder. “But don’t completely outsource the certification process,” she stresses. “Then sustainability comes alive within your own organisation and you can take steps faster.”

“It is precisely when you understand it yourself and start working with it that you see where the opportunities lie”

Demands for sustainability 

De Vries Stolwijk recently concluded a project (apart from a few final works) for regional water authority De Stichtse Rijnlanden, in which the CO2 Performance Ladder was used in the tender. Only companies that already held a level 5 certificate were allowed to bid for the tender. For De Vries Stolwijk, this meant that the competition pool was much smaller and it was easier to win the contract. 

The execution of the project also included various sustainability requirements. For instance, an additional requirement was that all machines used had to use the more sustainable fuel HVO 100. In addition, the trucks used had to meet at least the Euro 5 emission standard and machines had to have at least a Stage 4 engine. In addition, De Vries Stolwijk tried to combine the supply and removal of materials as much as possible.

The ball is in the government’s court

The fact that regional water authority De Stichtse Rijnlanden used the CO2 Performance Ladder for this tender is part of a broader trend, Van Houwelingen notes. More and more contracting parties are embracing the tendering instrument and (more importantly) are also achieving certification on the Ladder themselves. The latter is important, she says:

“If governments also get certified, they have a much better understanding of how the CO2 Performance Ladder works and what the possibilities are”

“In addition, they must then also reduce CO2 in their own supply chain,” says Van Houwelingen. “That stimulates collaborations between tenderer and contractor and then suddenly much more is possible in terms of sustainability.” Such cooperation is important, she concludes: “Companies (and certainly SMEs) cannot do it alone. We really have to do sustainability together.”

The CO2 Performance Ladder in your country?

Interested in reducing carbon emissions in your country with the CO2 Performance Ladder? Get in touch to find out how the Ladder can be used in your organisation as sustainable procurement tool and CO2 management system.

Maud VastbinderGet in touch