Refurbishment of the Kanaalstraat (Canal Street) in Utrecht

Utrecht's Kanaalstraat (Canal Street) is not only frequently visited by locals, but even attracts people outside the Netherlands. The street owes this to its multicultural diversity; a large number of market-like shops offer a specialised range of products from different cultures.

However, this large influx of visitors also has a downside: the street is very busy. Utrecht Municipality has long wanted to address this. The street had to become more liveable and radiate tranquillity, providing more space for encounters. Moreover, the municipality wanted a greener streetscape. To achieve this, the 'Refurbishment of the Kanaalstraat' project was put out to tender. For a sustainable implementation of the project, the CO₂ Performance Ladder was used. Construction company Kroeze Infra won the tender and started implementation in November 2022. We spoke to Koen Senders, project director at Kroeze Infra and Freek Prozee, project director at the municipality of Utrecht, about the role the Ladder played during the project and the CO₂-reduction measures taken.

The project

To better regulate the heavy traffic on Kanaalstraat, a traffic-safe design with a speed limit of 30 kilometres per hour was needed. Before the works the street was a busy two-way street – now it is a one-way street with wide pavements. Prozee: 'The redesign should create a calmer streetscape, among other things by preventing double parking. Moreover, as a municipality, we want to reduce car use and give cyclists space in the street.'

To realise this new streetscape, the cycle paths and road surface of the entire Kanaalstraat were redesigned and all existing paving removed. In the process, the old sewers and house connections were replaced with separate dirty water and rainwater sewers. In addition, a new ground-level layout was made and the investment into greening the street was considerable: 89 trees have been planted and small gardens and planters were installed on the street. Finally, the square in front of the Antonius Church was redesigned, public lighting replaced and work was carried out on the traffic control system.

Tendering with the CO₂ Performance Ladder

The municipality of Utrecht used the CO₂ Performance Ladder in the tender to select the right contractor for the redevelopment of the Kanaalstraat. In doing so, the Ladder was used as part of the award instrument. 30% of the tender consisted of price and 70% of quality criteria, which included CO₂ reduction. A total of 100 points could be earned, including up to 10 points for the CO₂ Performance Ladder when certified at level 5. Prozee explains that due to the fierce competition, likely only contractors with an ambition level of 4 or higher on the Ladder would have a chance of winning the contract: ‘The higher the level on the Ladder, the more points the contractor received. The CO₂ Performance Ladder had a weighting factor of 5%. Kroeze Infra achieved the maximum score with level 5.’

Adjusting diesel use

For the municipality of Utrecht, it was important that the project was carried out as sustainably as possible. A contractor with level 5 on the CO₂ Performance Ladder was therefore chosen. For Kroeze Infra, this meant that they took various sustainable measures when carrying out the project. The main focus was on diesel consumption. Senders: 'Most of our emissions come from diesel consumption, mainly for our cars, trucks, cranes and all our other equipment. In recent years, we have been working on saving as much as possible in this area, including the Kanaalstraat project.'

To green their diesel use, Kroeze Infra is increasingly turning to HVO diesel. HVO stands for 'Hydrotreated Vegetable Oil' and is made from waste vegetable oils and residual waste. There is no longer any fossil oil involved. The company's ambition is to use diesel with an increasingly higher HVO percentage. For the Kanaalstraat project, HVO20 was used. Of course, besides diesel use, it is important that the vehicles and equipment used are themselves economical. In this respect, the biggest emissions occur with commercial vehicles transporting the equipment. Senders: 'For all our projects, including the Kanaalstraat project, we use Euro 6 trucks. This is a fuel-efficient type of vehicle and its nitrogen emissions have been reduced to 0.4 grams per kilometre.'

Efficient supply of equipment and reuse of materials 

More sustainable vehicles make a difference, but it is also important to minimise transport distances. Prozee says that this was taken into account during the project: 'Kroeze Infra used a 'Just in Time' (JIT) system for the supply of equipment. They had their depot close to the construction site, so they could drive back and forth with smaller equipment. This minimised the distance driven and thus the CO₂ emissions.'

Attention was also paid to reusing materials. For instance, the kerbs and paving stones in the street were reused. Prozee: 'The sum of all these measures makes an impact on a project like this.'  

'The sum of the sustainable measures taken makes an impact on a project like this.' - Freek Prozee, project director at the municipality of Utrecht

More commitment to electric equipment

Besides the method of using diesel, deploying as much electric equipment as possible is important for sustainable project implementation. For the Kanaalstraat project, Kroeze Infra worked with smaller electric equipment, such as hand equipment and tools, small vibrating plates and electric pumps. Making the switch to even larger electric equipment is an important ambition of the company, but also a challenge, Koen Senders points out: 'Electric machines are currently still a lot more expensive than non-electric ones. Moreover, the machines cannot run as long and are usually not usable for a whole working day. In addition, getting enough power is a challenge. When we apply for a construction connection, it can take quite a long time before we actually get power. Since most of our projects take a year to complete, that often takes too much time.'

There is a tipping point taking place in the market, though, and that offers opportunities for the near future. Senders: 'The deployment life of electric machines is getting longer and longer and the price is going down. It's all pulling together more. This makes it increasingly feasible for us as a construction company to switch to electrical equipment. That, of course, is a good and important development.'

'The deployment life of electric machines is getting longer and longer and the price is going down. This makes it increasingly feasible for us as a construction company to switch to electrical equipment. That, of course, is a good and important development.' - Koen Senders, project director at Kroeze Infra

Making gains in the chain

Part of working with the CO₂ Performance Ladder is making the chain more sustainable. After all, emissions do not only occur within and by the organisation itself, but also in the chain in which that particular organisation works. This also applies to Kroeze Infra, which tries to influence material scope 3 emissions in addition to its scope 1 and 2 emissions. Senders: 'Our main chains are subcontracting and articles of concrete and stone. As part of the Ladder, we drew up a chain analysis on diesel. It showed that most CO₂ reduction can be achieved with our road builders. This is why we are increasingly having them work with HVO diesel. This measure was not specifically deployed at the Kanaalstraat project, but we are rolling out this policy to 10% of our projects in the near future.'

The Ladder forces organisations to stay sharp

Kroeze Infra has been certified at level 5 of the CO₂ Performance Ladder for 10 years. The sustainability instrument has ensured in recent years that the company has not slackened in its pursuit of green ambitions. Whether on the Kanaalstraat project or elsewhere, the Ladder is embedded in their sustainability policy. Senders: 'Working with the CO₂ Performance Ladder forces you as a company to focus on the sustainable measures you take every year. It is a good stick to keep you focused and to grow in that area. It can relate to various aspects of our work, for instance when it comes to trucks that are now all Euro 6 or equipment that is increasingly electric. The Ladder encourages this.'

'Working with the CO₂ Performance Ladder forces you as a company to focus on the sustainable measures you take every year. It is a good stick to keep you focused and to grow in that area.' - Koen Senders, project director at Kroeze Infra

Experimentation is also important when it comes to sustainability. For Kroeze Infra, it helps that there is a sustainability instrument that necessitates testing new methods. Senders: 'Meanwhile, for example, in more and more projects we have solar panels on the worksite, which provide electricity. Something like this starts as a specific measure on an initial project, but soon becomes part of our general measure list.'

Sharing sustainability steps

The CO₂ Performance Ladder encourages organisations to communicate about the CO₂ reduction on specific projects. Sharing the sustainable actions taken is part of working with the Ladder. This therefore means that Kroeze Infra communicates internally and externally about what was done during the Kanaalstraat project to build as sustainably as possible. Senders: 'By working with the Ladder, we have started to communicate more structurally about sustainable construction. We do this by posting messages on our website and sharing a biannual communication message with our clients in which we provide insight into our footprint of the specific projects. We are working to get our internal employees on board in the field of sustainability by holding an annual toolbox session and organising a mobility battle. This is how the CO₂ Performance Ladder encourages the spread of sustainability ambitions; internally and externally.'

The Kanaalstraat project started in November 2022 and was delivered in April 2024.