Room for new techniques in construction zero-emission bus depot Breda

The new bus depot in Breda is a good example of how the province of North Brabant and municipalities are working together to make public transport more sustainable. The complex on Druivenstraat is being developed in-house, is fully dedicated to electric buses and is also set up with sustainable buildings and installations. No less important is its strategic location: the new complex is next to the Oosterhout bus lane, allowing buses to reach Breda station in no time. Another plus: the grid connection had just been arranged when congestion on the electricity grid began to rear its head. 

Stijn Smeulders, deputy with the Urban Development and Mobility portfolio, outlines the motivation for building a new depot. "We, like every other public transport authority in the Netherlands, have signed a covenant with the State to run only zero emission buses by 2030. The main reason is to improve air quality in urban areas. What we need for that is depots with charging infrastructure. And if we get the chance to do so, we will try to get them back under our own management and not rent them from third parties. After all, by buying or developing depots in-house, we can create a level playing field for bus companies in tenders."

To make this possible, the province purchased an unused nearly 4-acre piece of land between Druivenstraat and Oosterhout Bus Lane in 2021. "A godsend," Smeulders said. "A good, fast connection between bus station and depot means that no time is lost where the bus cannot carry passengers. At the current bus depot on Slingerweg, buses have to make their way through regular traffic to get to the station. Therefore, the new spot is ideal. The grid connection was requested just before grid congestion set in. Although we are the largest shareholder with grid operator Enexis, we had to connect right at the back, but that was just in time. The grid connection is currently the most important factor when it comes to site selection. That is quite a challenge for other projects."

But not for Breda, and so on Druivenstraat rises the largest depot in the province. Most of the space is taken up by the outdoor parking area that will soon be able to accommodate 180 electric buses. A portion is reserved for a building that houses offices, a canteen for the drivers, a bicycle shed, a car wash and maintenance facilities for the buses. 

Construction of the depot started in October 2023 and is being carried out by the combination G. van der Ven BV Aannemingsbedrijf/KWS Infra. "We are working in a construction team with the client province of North Brabant and Witteveen+Bos," says Eefje Mollet, Technical Manager at G. van der Ven. "As the executing party, we were at the table early on. That gave us the opportunity to test the design for cost and manufacturability, which led to a number of adjustments and optimizations. We mainly work for governments and public-law organizations and already have experience building bus depots, so you can shift gears faster. What also helped here was that we are working with a client who has expertise in the field. That makes choices easier, which is useful in a project with short lead times." 

Work on the structural work is currently ongoing. "The foundation consists of mortar screw piles with edge beams poured in-situ," Mollet continued. "Four pits for column lifts for bus maintenance have been made and a long pit for the MOT lane where the RDW can inspect buses. Under the lifting bridges, the floor is additionally underpinned. The building will have a SolarEis climate control system. This smart system works like a thermal battery and heats the building in winter and cools it in summer. For this purpose - with the CSM system (Cutter Soil Mix walls; ed.) - a building pit was created in which the concrete basement basin for the SolarEis will be realized. SolarEis will last for decades and save the province a huge amount in energy costs." 

Sustainability weighed heavily in the tender, emphasized Delegate Smeulders. "We are not destitute and can go for quality and carry sustainability a long way. We have already been voted the most sustainable tenderer in the Netherlands five times in a row. The Breda depot will be another fine example of that. In addition to the SolarEis system, solar panels will also provide sustainable energy, the building will have heat pumps with underfloor heating, and the thin concrete panels of the fire walls will be the first in the Netherlands to be equipped with basalt reinforcement. This reinforcement is stronger and lighter than steel, non-conductive, expands less and is environmentally friendly, as it is fully recyclable and non-polluting. To actually give the building a function for ecology, the roof is provided with a thick layer of substrate and rising greenery. A nice bonus is that it proved possible to extend the project area toward Druivenstraat. This offers the possibility of additional green compensation, in the form of an ecological zone 300 meters long and 15 meters wide with height differences, fauna passages and more trees on the side of the bus lane." 

And there is more. Mollet: "The shell of the depot is constructed of steel, with hollow-core slab floors and a steel roof in a demountable structure. Soon, HSB facades will be assembled with bamboo as the facade material. That too is a sustainable and fast construction method that provides a quick turnaround time. Naturally, we keep a sharp eye on nitrogen emissions on site. To this end, we organize logistics as smartly as possible, use electric equipment wherever possible and work with NOx filters so as not to exceed the maximum project emissions."