Sustainability

All of Heijmans’ activities have a long-term impact on our living environment. With this in mind, our goal is to have a positive impact on our planet by 2030. We use sustainable solutions and working methods, actively contributing to a better climate, more biodiversity and a good water balance. We are making the transition to circular working methods in close collaboration with all the links in our chain. We are convinced that this will help create a liveable future.

Climate

Heijmans wants to play an active role in the transition to a sustainable society. We feel partly responsible for the future of the Netherlands. It is vital that we become climate neutral and take concrete steps in that direction. This is not an easy task, but it is necessary. This is why we take our role as a sustainable leader seriously and have deliberately set the bar high in terms of our own targets.

• By 2030, we will be 100% CO₂e neutral in our direct business operations and electricity consumption (known as scope 1 and 2). This means that our greenhouse gas emissions will be reduced to zero. Since 2019, we have reduced our scope 1 and 2 emissions by approximately 61%, which amounts to a reduction of around 26 ktonnes. We will realise additional reductions with the help of sustainable measures applied to our vehicle fleet, equipment, offices and building sites.

• By 2030, we will have reduced greenhouse gas emissions in our chain – scope 3 – by at least 50% compared with 2019. We will limit the emissions from the production materials we purchase.

• By 2040, we will be working and building completely – across the board – in a CO₂e-neutral manner. This means that neither Heijmans nor any other party in our chain will be releasing greenhouse gases as a result of our operations.

Ultimately, at Heijmans we want to do more than just reduce our climate footprint. We believe in making a positive contribution to the climate by taking measures that have a favourable impact on our planet. For example, we aim to achieve a positive CO₂e balance in 2030 through the intrinsic management of the impact of stored and avoided CO₂.

Science Based Targets initiative (SBTi)

The Paris Climate Agreement sets out agreements to drastically reduce global greenhouse gas emissions. The countries that have signed the agreement, including the Netherlands, agree that the increase in the average global temperature should be limited to below 2 degrees Celsius, and preferably below 1.5 degrees. The European Union has set a goal of being completely climate neutral by 2050. Heijmans wants to realise this for its own footprint as early as 2040. We recognise that this is an ambitious goal, but also feel that it is in keeping with our pioneering role in the construction sector. Heijmans is one of the first Dutch construction companies to have committed to achieving a net-zero position by 2040.

In year under review, we had our sustainability ambitions assessed by the Science Based Targets initiative. The SBTi is an independent organisation that assesses whether companies' climate goals meet the scientific criteria agreed upon to limit global warming. We are proud that the SBTi has given a positive assessment of our ambitions and related plans for achieving our reduction targets.

Offsetting and carbon credits

As an intermediate step on the road to completely CO₂e-neutral working and building by 2030 for our direct emissions, we will offset the emissions that are currently still unavoidable. We do this by investing in so-called carbon credits, which come from sustainable energy or forestry projects in Europe. We are also committed to voluntarily greening our energy supply. With Guarantees of Origin (GOs), we ensure that the electricity and gas used in our operations comes from renewable energy sources such as wind, solar, hydropower and biomass. For more information on our offsetting policy and the origin of these credits, see the ‘Climate - Offsetting with carbon credits’ section in the sustainability report of this annual report.

Sustainable equipment use

One of our goals is to use raw materials and other materials as efficiently as possible and to reuse them whenever possible. This requires close cooperation with suppliers and other partners in the chain. Only by acting together will we be able to realise our climate targets for scope 3 emissions.

Circular working

The drawing board is the starting point for circular working. Firstly, we identify the greatest environmental impact and then design using materials that have a low or reduced impact on the environment, such as timber and other sustainable alternatives. This includes looking at the possibility of storing CO₂ for longer periods in completed construction projects. We are also developing solutions to make CO₂ intensive materials such as concrete, asphalt and steel less harmful. In close cooperation with research institutes and other partners, we are working on the use of alternative raw materials such as biobased building materials. We meticulously record all the materials used and verify that they are non-toxic and can be ‘detached’. And we manage to retain value by recycling materials to a high standard and extending the lifespan of existing structures, buildings and infrastructure through careful management and maintenance.

Impact analysis of material flows

In 2024, we conducted an extensive impact analysis of the CO₂e emissions of the three most important material flows for our construction activities: asphalt, concrete and steel. The results of this analysis prompted us to develop concrete courses of action in line with the Dutch Concrete Agreement. We have also developed a dashboard that provides continuous insight into our performance and the progress we are making. This gives us a solid basis for reaching agreements with suppliers on the continued reduction of our Scope 3 CO₂e emissions.

Concrete agreement

Concrete is one of the raw materials that Heijmans uses the most. It also generates considerable greenhouse gas emissions. In close cooperation with clients, other construction firms and suppliers, Heijmans is working within the framework of the National Concrete Agreement on the much-needed sustainability of this sector. We need to accelerate the transition. This is why we have signed a letter of intent with the aim of setting ambitious requirements for CO₂e reductions in the procurement of concrete.

More sustainable applications with concrete

In 2024, Heijmans took a number of significant steps towards making concrete more sustainable. For example, we successfully applied geopolymer concrete during the renovation of the Gemini-North research building on the grounds of the Eindhoven Technical University. In this alternative material, cement has been replaced by residual products, achieving a CO₂ reduction of 46% and a lower environmental cost indicator (ECI). In Rijen, we used self-healing concrete for the first time on a ProRail railway viaduct. This enables us to extend the lifespan of structures and as a result significantly reduce greenhouse gas emissions. And in the town of Lent, we used the innovative ECO pile as foundations for houses for the first time. These hollow concrete piles combine maximum load-bearing capacity with the minimum use of materials, resulting in an average CO₂e reduction of 25% per pile. We are also making additional reductions in our emissions thanks to more efficient transport due to the lower weight of the hollow piles.

Biobased materials: hemp fibre

To make our operations even more sustainable, we have committed to the use of biobased materials, such as timber in the Horizon concept timber-framed houses. We are also investigating the use of hemp fibre. As part of the ‘from our own country to our own premises’ programme, we have started to grow, process and use hemp fibre as a sustainable alternative to traditional insulation materials. This material offers several advantages: it reduces greenhouse gas emissions during construction, improves the indoor climate thanks to its moisture and temperature regulating properties, and its cultivation requires no chemical pesticides or fertilisers. In collaboration with GreenInclusive, in 2024 we harvested our first hemp crop on 6.5 hectares of land in Friesland. The harvested hemp is processed into ‘Hempwool’ insulation material and used in projects such as the Thedemaborg new-build residential development in Nietap. In addition, we are investigating whether hemp fibre might eventually serve as insulation material for the homes produced in our timber-frame houses production facility in Heerenveen.

Waste monitor

In 2024, we introduced the Waste Monitor at Heijmans. This is an innovative dashboard that we developed with waste processor Renewi. This dashboard, which contains information from a total of 25 different suppliers, provides insight into waste flows, separation percentages and CO₂e emissions down to project level. This tool is a useful instrument for project teams and managers to check whether they are on track and to make any necessary adjustments. Not only will the Waste Monitor help us to realise our ambition to use only sustainable working methods by 2030, it also provides the data we need to meet the reporting requirements of the Corporate Sustainability Reporting Directive and the EU Taxonomy. The CO₂e emissions from the waste we produce at Heijmans currently account for around 1% of our total emissions.

Emission-free transport and equipment

For our operations that fall under scopes 1 & 2, we want to minimise our emissions and reduce our total ecological footprint. We will do this by taking concrete measures in the areas of transport and equipment.

Emission-free construction and transport

In 2024, we once again took a number significant steps on the road to emission-free construction. For our work at Schiphol Airport, for example, we deployed our first electric sewer inspection truck. We also put a 40-tonne electric caterpillar excavator into operation at the airport. We are making significant progress with the electrification of our vehicle fleet. From 2023 onwards, our lease car package consists exclusively of electric cars for new orders, and we have shortened the current lease contracts for vehicles with combustion engines. Our goal is to have an all-electric fleet of cars by the end of 2025 at the latest.

We also invest continuously in making our building sites more sustainable. This includes using energy-efficient LED lighting and promoting low-fossil-fuel alternatives, such as HVO100, both at Heijmans and among our suppliers and subcontractors. And we always use green energy, preferably from nearby wind farms. 

Emissions data at project level

With the aid of our supply chain portal – in which we digitally record incoming and outgoing logistics – we made significant progress last year in gaining more insight into emissions in our construction processes. The portal enables us to register the emission data of all transporters and suppliers at project level, enabling us to plan, analyse and optimise logistical flows more effectively. We have now successfully completed this application, which we tested in the Construction Logistics Living Lab in collaboration with TopSector Logistics. We are now using the supply chain portal in an increasing number of construction projects. In addition to providing insight into greenhouse gas emissions, the portal encourages our logistics chain partners to reduce emissions and make their processes more sustainable, and to consult with each other in the chain to implement joint improvements.

Biodiversity

At Heijmans, our maxim is to leave the environment in which we work in a better state than we found it. For us, a healthy environment is synonymous with healthy biodiversity. We recognise that our business operations can have a direct negative impact. For example, our greenhouse gas emissions contribute to climate change, loss of biodiversity and damage to ecosystems. This is why we see it as our duty to make plans and take measures to promote biodiversity. In all our projects, we specifically work to strengthen species richness, from micro-organisms and animals to plants and trees. We are aware that these together form essential ecosystems and are indispensable for our general well-being and more specifically for our health and food supply.

Better soil

In 2024, we worked closely with Wageningen University & Research (WUR) to develop seven principles and practical measures to protect and improve soil conditions in construction projects. The aim of this set of guidelines is to prevent or minimise damage and to restore and improve soil quality. We are providing the construction sector with tools to build more sustainably and to make a positive contribution to biodiversity and climate adaptation. Thanks to the combined knowledge of Heijmans and WUR, we now have measures we can apply directly to protect the soil as a valuable basis for a healthy living environment.

Measurable biodiversity

At Heijmans, we would like to demonstrate that it is perfectly possible to combine nature and the built environment. We do this in a nature-inclusive manner and in various ways, for example by paying attention to nature conservation in area developments, creating public green spaces, implementing an adapted, nature-friendly mowing policy, building nesting spaces for birds into homes and installing bee hotels. We integrate homes, civil engineering structures and other buildings into the natural environment as much as possible, and vice versa. These measures and applications have a measurable positive impact on biodiversity. In 2024, for example, we published the initial results of a long-term study into the development of the natural environment in the Parijsch new-build residential neighbourhood in Culemborg. The study showed that nature-inclusive measures, such as nesting boxes and green spaces, help increase the variety of bird species, insects and bats in the area.

Our approach in the Parijsch neighbourhood is now being used right across the country and was the inspiration for the adoption of a motion submitted by MPs Thom Van Campen and Laura Bromet. This motion called for national guidelines for local authorities, with a robust assessment method to speed up the permit procedures for nature-inclusive and climate-adaptive housing projects.

Sustainable area developments

Our current goal is for all area developments in which Heijmans is involved to achieve an NL Greenlabel with an A rating or level 5 on the Nature ladder (Natuurladder) by 2030. This means we are deliberately setting the bar high for the promotion of sustainable area developments. The NL Greenlabel method, which was updated in 2023, assesses projects based on aspects such as energy, biodiversity, mobility and water quality. Various Heijmans projects have already been awarded an A or B rating. For example, the Maanwijk project in Leusden was awarded an A rating and the De Hooge Riet project in Ermelo was given a B rating. To support area developers, we have produced a manual with practical tips and solutions that can be used from initial design to realisation.

Nature ladder

Heijmans is the joint developer of the Nature ladder (Natuurladder), a tool that helps construction teams working on infrastructure projects improve biodiversity. In 2024, we refined and expanded this tool and transferred it to the Deltaplan Biodiversity Restoration Foundation. This organisation will now make the Nature ladder available to the entire construction sector. We hope this helps to raise awareness and boosts the implementation of climate-adaptive building and the restoration of the natural environment in the Netherlands.

Birds in new-build neighbourhoods

We have stepped up our cooperation with the Dutch Society for the Protection of Birds (Vogelbescherming Nederland) to improve the living environment of birds and people in new housing developments. In a joint effort, we are assessing the effectiveness of nature-inclusive measures in residentia developments. These range from recording bird sounds (to check diversity) to testing special window foil to prevent so-called window casualties. Our intensive collaboration is aimed at giving birds a pleasant place to live in urban areas. We are actively committed to improving biodiversity in the Netherlands and helping to create a healthy, sustainable living environment by focusing on nature-inclusive construction and initiatives such as the Nature ladder (Natuurladder) and BioBuddy.

Nature as a solution

At Heijmans, we want to learn as much as possible from nature. That is why we are enthusiastically exploring the possibilities of so-called ecosystem services (ESS). These are development strategies that can be used in projects if they pass quality and suitability assessments. One example is the use of specific bacteria to combat soil pollution. For example, in 2024 we conducted research into the biodegradation of microplastics from tyre abrasion on motorway verges. In the Netherlands alone, this results in 10,000 tonnes of environmental pollution every year. Together with the Deltares research institute and Avans University of Applied Sciences, we tested microorganisms for their decomposition potential. And the results were promising. At Heijmans, we believe that it is now up to politicians, scientists and industry to act, because there is an urgent need for stricter regulations, follow-up research and a significant improvement in the sustainability of car tyre production. We are happy to share the results of our exploratory research with stakeholders and other interested parties. And we are keen to remain involved in the development of regulations and follow-up research in the near future.

Water

Water is the basis of all life on earth. Due to climate change, we are facing more and more floods and periods of drought. In the Netherlands, we can and must use rainwater, groundwater and surface water much more intelligently. Heijmans has an impact on the water system through our operations in public areas and at our own offices and building sites. We also have the in-house knowledge and expertise to improve the quality and quantity of water. This is why water plays such a prominent role in our projects. For example, we look at possibilities for buffering water and using rainwater to water green spaces. We also use innovative solutions to keep our water system safe. In 2024, we drew up the ‘Water Matters!’ vision document, which outlines some of our strategies for effective water management in the landscape. This vision is based on four pillars: water quality, water balance, water use and water safety.

Water quality

We want to ensure that our working methods do not have a negative impact on water quality. In effect, this means we are acting in accordance with the Dutch Water Framework Directive (WFD).

Our approach already includes various measures to improve water quality. For example, we install wadis when we redevelop streets. These wadis are used to store water, but also to purify water that runs off the road. When we pump out water, we already take into account the water quality requirements laid down in the relevant permits. In addition, we installed a plastic trap in the canal from Ghent to Terneuzen to remove plastic from the surface water.

Water balance

In our projects, we always take measures to prevent any risk of flooding and soil subsidence. These measures include the use of various instruments, like the Ecology, Soil and Water Scan (EBW scan) and Sustainable Design Principles (SDP). We apply the SDP in area development and infrastructure projects. We refined these principles in 2024 and will start using them in practice from 2025 onwards.

In 2023, we became the first nationally active construction company to join the WaterBank, an initiative aimed at working closely to improve the water balance in the Netherlands. We are applying innovative solutions for circular water management in the large-scale urban renewal project Hart van Zuid in Rotterdam. We have installed an urban water buffer that can store up to 20 million litres of rainwater per year. The water is then used for toilet flushing and to clean the nearby Ahoy event centre. Heijmans started expanding the terminal at Eindhoven Airport in 2024. The design incorporates innovative solutions in the areas of sustainability and water use. The roof of the new terminal will be covered in sedum plants for better water collection and insulation, while a water basin will collect rainwater and reuse it for toilet flushing. In 2024, we also started construction on the Spinaker project in Tilburg, which includes a green entrance plaza and a small ‘pocket park’. This neighbourhood park will have a dual function: in addition to providing space for people to meet and recreate in a green environment, it will also serve as a reservoir for excess rainwater. We will build the parking spaces for residents on ‘crates’ that can also be used to collect water. These and other applications demonstrate our integrated approach and our ambition to build in a climate-adaptive way and to enter into partnerships for sustainable water management.

Water use

Of course, we also keep track of our own water use with the aim of reducing our ‘water footprint’. We distinguish between the following focus areas: drinking water use in our own business operations, drinking water use in buildings and water use in the production of raw materials.

We are committed to ambitious goals that will certainly exceed the national reduction target of 20%. We will communicate our exact goals in 2025, when we will have a clear picture of the entire water cycle.

In 2024, Heijmans joined the Gelderland Water-Efficient Neighbourhoods Construction Roundtable (Bouwtafel Waterzuinige Wijken Gelderland). This initiative focuses on guaranteeing clean drinking water by encouraging the construction of water-efficient neighbourhoods. With this goal in mind, we are developing scaleable solutions to support the National Action Plan for Water Conservation together with the province of Gelderland, drinking water company Vitens and various water boards. This could include using rainwater to flush toilets, for washing machines and for outdoor taps.

Water safety

Climate change has extra significance for the Netherlands, which lies largely below sea level. The rise in sea levels and river water levels, due in part to the melting of snow in the mountains, means that we must take timely measures to prevent flooding.

At Heijmans, we are working on reinforcing our national dyke system and building new housing developments that can withstand high water levels. So we are actively contributing to keeping our water system safe and making it safer. In 2024, we started nature conservation projects around the Lauwersmeer dyke in Groningen. These are part of the Flood Protection Programme (HWBP) initiated by a number of water boards and the Dutch Ministry of Public Works and Water Management.

In addition to reinforcing the dyke, we are also taking measures to improve biodiversity in the area. As part of this initiative, we are creating a 22-hectare natural salt marsh, a 70-hectare tidal area and a natural transition between the dyke and the Wadden Sea. By choosing an integrated approach, we are creating a link between flood risk management and the development of the natural environment. We are also continuing to work on reinforcing the dyke between Gorinchem and Waardenburg. This project is part of the Dutch Ministry of Public Works and Water Management’s Flood Protection Programme and aims to ensure that the dykes meet the new safety standards that have been in force since January 2017.