design philosophy

Sustainable design is a key aspect of our firm’s core values. Our ambition is to take a leading role in sustainable bridge design. Our sustainable design philosophy:

  1. Take initiative. Each project is an opportunity to create a sustainable future. Don’t wait for others to take the first step.
  2. Keep learning. Sustainable design is evolving rapidly. Every day we learn and improve our knowledge, skills and methodologies.
  3. Work as a team. Only in close collaboration with clients and partners we can actually achieve our sustainability goals.


We were one of the initiators and co-authors of the first Dutch standards for the ‘Industrial, Flexible and Dismountable’ (IFD) construction of movable and fixed bridges. Using standard parts and standardised details, IFD-bridges become part of a circular economy and greatly improve maintainability and serviceability. The development of these standards was led by the Royal Netherlands Standardisation Institute NEN, in close collaboration with a team of engineers, contractors and clients. The guidelines were published in 202 and 2021 and can be downloaded from the NEN website:


In 2020, ipv Delft developed a sustainable circular bridge. In this innovative hybrid design, glued laminated timber beams and a thin concrete deck are combined to form a sustainable, highly durable and low-maintenance bridge. This bridge combines the low carbon footprint of timber and the durability of concrete. The laminated timber beams and the concrete deck slab are structurally connected by dowels, creating a strong structure. By using a cantilevered deck that protects the glulam beams, the life span of the beams is dramatically increased to an expected life span of 80 years or more. The bridge was developed in close collaboration with Dutch construction company Knipscheer and was an immediate success. The first bridges have already been built in Zwolle and Reimerswaal, both in the Netherlands.

timber structures

As fas as we’re concerned, timber is the building material of the future: it’s sustainable, renewable and versatile. For a 127-metre-long overpass at Zwolle (NL) railway station, we designed a bridge with glued laminated timber beams. The S-shaped bridge is designed as an elevated green walkway with trees, bushes and plenty of seating. This groundbreaking design came about in close collaboration with Zwolle city council, Dutch railway authority ProRail, coordinating architectural office Karres + Brands and Miebach engineers.

life cycle analysis

Calculating the total environmental costs of a project is something we do a lot. More and more, the outcome of these calculations helps us decide on what material to use or what design choices to make in order ot minimise the impact of our designs on the environment. In the Netherlands, we generally use the specialised application called DuboCalc for these calculations. DuboCalc is a Sustainable Construction Calculator developed by Dutch transport authority Rijkswaterstaat to calculate the sustainability and environmental costs of procurement and compare them for different materials or design choices.  The method is based on the methodology of Life Cycle Analysis (LCA).


At ipv Delft we believe that bridges can contribute to the urban ecosystem they are part of. Using nature-inclusive design strategies, we were able to enhance ecological conditions for local vegetation and wildlife species in many of our projects. For the award-winning Depoldering Noordwaard project, bricks recovered from demolished farm buildings that were previously on the site were used for the new pumping stations. The brickwork has recessed mortar joints that provide an attractive environment for small organisms. The creek bridges have elongated bird branches, that provide a place for birds to sit and rest. Nesting boxes for bats were integrated in the walls.

Another nature-inclusive project is the Potmarge footbridge in Leeuwarden, which features nesting facilities for swallows in the concrete abutments.

more information?

call Ivo Mulders:
0031 15 750 25 73