Urban areas with plenty of greenery are pleasant to live in and attract birds, insects, mammals and other wildlife. Photo: Lea Rae / Shutterstock
Building projects are no longer just ‘grey’ but increasingly also ‘green’ and ‘blue’. Space is deliberately created for nature on, around or in the building, with the ultimate aim of having a greater range of plant and animal species in the city. But research shows that it is not always easy in practice.
Each balcony of the Trudo Tower in Eindhoven has a planter with metres-high trees and bushes. Together, the plants form a vertical ‘residential forest’ with 125 almost identical social housing units. The tower was designed by the architect Stefano Boeri, who previously conceived the world-famous, iconic Bosco Verticale in Milan. The sustainable residential tower block with hospitality outlets, shops and offices in the bottom floors was delivered at the end of 2021. The Trudo Tower is the first nature-inclusive construction project anywhere in the world for social housing.
“The property sector is in a huge state of flux,” explains project manager Marijke Dijkshoorn, who works for Wageningen Economic Research. “Nature-inclusive construction is increasingly on the agenda for governmental authorities and other parties in the property sector.” Dijkshoorn studies this new approach to building, which is slowly but surely becoming more popular. She and her colleagues catalogued the property sector’s options for nature-inclusive construction, and looked at what factors are the key to success or can act as obstacles.
Humans, animals, climate and business
There are all kinds of benefits to having nature in the city, as municipalities, property players and inhabitants themselves realise. Urban areas with plenty of greenery are pleasant to live in and attract birds, insects, mammals and other wildlife. What is more, green districts are better able to withstand extreme weather caused by climate change and are less prone to air pollution. Finally, many businesses see greenery as a plus point when deciding on a location and it is an important factor determining home purchases.
Each balcony of the Trudo Tower contains a planter for trees and bushes. This project is a great example of nature-inclusive construction for social housing in the Netherlands. Photo: Rosanne de Vries / Shutterstock
So there are a lot of benefits, but how does this play out in practice? In 2019, Dijkshoorn put this question to 89 organisations, mainly property developers, investors, architects, contractors and construction companies. A majority — 61 per cent — said they already took a nature-inclusive approach to construction. They did so both to help society at large and because it burnished their own image and helped them stand out. They attached less importance to the risk-return ratio. Nearly two thirds of the companies that were not already integrating nature in their projects expected to do so within five years.
The scope of the respondents’ nature-inclusive approach ranged from an individual measure, such as hanging up nest boxes, to greater integration of nature in the built environment. The most extensive form of nature-inclusive construction keys into the requirements of local animal species, such as certain species of insects, newts, birds or bats. The greenery on and around the buildings should also be chosen to suit the soil, hydrological conditions and the location’s history. Even parking is becoming greener, with hedges separating the cars and grass allowed to grow between the paving stones.
Greenery as lowest priority?
Despite the growing number of initiatives, urban greenery still often loses out to other priorities, as housing, work, food and energy production, transport and recreation are all competing for a limited amount of space. “And greenery is then often given the lowest priority,” notes Dijkshoorn, “whereby it only gets considered once all the other functions have taken shape.” The ambitions for greenery also tend to get toned down if the project runs into delays or if unexpected costs are incurred. Sometimes people are simply unaware of what is possible. Property players also doubt whether consumers are prepared to pay for more nature in the final analysis.
As Dijkshoorn’s study shows, the path to nature-inclusive construction is often strewn with obstacles and still requires more effort from the players involved than the business-as-usual option. But the conclusion is also that nature-inclusive construction is possible despite these obstacles. The crucial factors for achieving success are a clear vision, creativity, flexibility and a willingness to take risks. The perseverance of the parties involved is also important.
Greenery is often given the lowest priority and only gets considered once all the other functions have taken shape
More plants, bees, and owl boxes: nature-inclusive construction will be the new standard. And although there’s great interest in this approach, Wageningen University & Research senior transitions researcher Marijke Dijkshoorn-Dekker also notices that there’s a knowledge gap within the real estate industry. That’s why they’ve developed a tool to share the what, why and how of nature-inclusive construction. (UK subtitles available in video)
The housing corporation that ordered the construction of the Trudo Tower started by having its supervisory directors visit attractive nature-inclusive projects across Europe. This led to the engagement of the forward-thinking architect Boeri. It also meant that everyone on the supervisory board was singing from the same hymn sheet, as it were. In addition to the Italian architect and its usual contractor, the project developer also worked from the start with a company for landscaping and maintaining the greenery and with a tree nursery.
The construction industry does what it has always done. This transition means you need to break with those established practices
The green ambitions remained intact throughout the process, from design to construction, thanks to the efforts made at the start. When financial setbacks arose during the project, this did not lead to cuts in the budget for greenery; the nature-inclusive aspect was still given priority. Plans for green interior walls did have to be abandoned for financial reasons, but the trees and bushes on the outside were kept. The costs were reduced by electing for a more sober interior design. As a result, the additional costs for the nature-inclusive aspect were less than one per cent of the total costs.
The housing corporation that built the Trudo Tower is a pioneer in the transition taking place in the Netherlands. Another such pioneer is the property developer building a nature-inclusive residential district south of Haarlem on the grounds of the Wickevoort country estate. “The Wickevoort concept is trailblazing with its focus on more natural greenery, with less space taken up with streets and concrete. An important factor was involving the right experts with a shared goal from an early stage.” Another forward-looking example is Amsterdam Vertical: three buildings designed for a plot in Amsterdam Sloterdijk-Centre. Inevitably, various complex issues arose during the construction process, but the project vision of landscapes based on biodiversity did not prove a problem in this regard.
We face challenges in terms of construction, climate adaptation and biodiversity. Nature can be of great help in finding solutions for these challenges, such as creating roof gardens in Rotterdam to absorb heat. Photo: R. de Bruijn Photography / Shutterstock
Other players in the sector are less pioneering, but Dijkshoorn says they are on the point of following suit. “The building industry works in a certain way, doing what it has always done,” she explains. “This transition means you need to break with established practices and bring about a change in behaviour. Though it would help if they could see more inspiring case studies.”
The three cases mentioned above and the survey results have now been included in a brochure (in Dutch) for the property sector. Dijkshoorn and her colleagues are also working on a communication tool (in Dutch) that will show how firms can build in a nature-inclusive way. She wants to offer pointers that can get the conversation about nature-inclusive construction going.
Dijkshoorn is optimistic about the transition. “Nature-inclusive construction is higher and higher on the agenda. We face challenges in terms of construction, climate adaptation and biodiversity. Nature can be of great help in finding solutions for these challenges. Even when space is scarce, you can still have greenery on roofs, facades and balconies. I see the sector is changing and nature is increasingly getting the attention it deserves. In my opinion, nature-inclusive construction is so important that it will inevitably become the standard in some form or other.”
Share this story