Showcase: the circular renovation of C-Bèta at Schiphol Trade Park

  20 November 2020  |    Interview

What lessons have the commissioning client, architect and contractor learned?

Thinking outside the box, being prepared to get it together as a team, and always being ready to work creatively and find tailor-made solutions. These seem to be key values for circular building. In the heart of the municipality of Haarlemmermeer, area developer SADC recently renovated a barn that is part of C-Bèta, a former farmstead. Workspaces have been created in the ‘new’ barn, making use of recycled building materials where possible. Its roof and façade were also renovated following circular principles. The transformed building now stands proudly in the park, but there were certainly some bumps in the road along the way. Here, we look back on the process, paying heed to an interesting list of lessons learned for circular building.

“This building shows what we stand for,” explains Isaac Roeterink, project manager at SADC. “And for all of us – the commissioning client, the architect, contractor and even the suppliers – it’s been an adventurous learning journey, albeit an unpredictable one back at the beginning.” Together with colleague Eelco Kienhuis, Isaac is involved in the evaluation of the renovation of this old barn at C-Bèta, SADC’s experimental circular testing ground in the farmhouse of a 125-year-old farmstead in Hoofddorp. He’s joined by representatives of the other companies who carried out the renovation: Erik Brusse of DOOR Architecten in Amsterdam, and project manager Jan Altorf, commercial manager Martijn Icke and planner Bianca Woutersen of Heembouw Kantoren B.V. from Berkel en Rodenrijs. The three companies signed off on the final designs for the barn and turnkey building contract at the start of 2020, by which time at least a year had already been dedicated to drafting the preliminary design and, in particular, sourcing reusable building materials.

Practice what you preach
The farm is situated on Rijnlanderweg at Schiphol Trade Park, close to the A4 motorway, precisely at a point where dynamic industry and existing buildings meet. SADC is developing the area based on circular principles. Brick by brick, the most sustainable and innovative business park in Europe is emerging. And at the heart of this area, C-Bèta is the place that will accelerate the transition to the circular economy. After all, it’s here that startups and scale-ups have the space to work, come together, and share knowledge about circular area development. Soon after it opened in 2018, SADC had to begin exploring options to expand it because the demand for flexible workspaces was already much greater than the availability. But the decision to build something new or reuse an existing building turned out to be an easy one. “For us, C-Bèta is a place where companies can work, experiment and run events,” says Isaac Roeterink of SADC. “We firmly believe you should practice what you preach. SADC wants to drive the circular transition and we demand more from our tenants in this area. So you have to show that you’re committed to doing it yourself.”

“If you take a traditional approach, it’s almost impossible to get this type of project off the ground”
Isaac Roeterink, SADC

So it was decided that they would renovate the vacant barn measuring 1,000 m2 next to the old farmhouse. “Our assignment was broad: we have a building with a limited lifespan, we know it has undergone some damage and that it contains asbestos, and we want to create workspaces that we can easily dismantle and rebuild elsewhere when that time comes,” Isaac says. The decision to take a circular approach immediately set the bar high.

Who takes the lead?
First, the final result: until the beginning of 2020 there was a large, old barn that was once used to store potatoes and other crops, and various agricultural vehicles. Seven months later there is a circular, multi-tenant workspace, gleaming like a new building. If you take a look at the list of materials used (see box 2), it reveals an essential issue with circular construction: it takes a lot of time and effort to find suitable materials and then for them to be available at the right time. And the process of design, execution and material selection is also difficult to plan and streamline. At what point should the contractor make a start with sourcing materials? During the initial design phase or later, once the plans and preferences have largely been established and the calculations made? Or perhaps the architect should base their work on the list of available materials drawn up by the contractor? Neither route is tried and tested. The core aspects of circular building are feasibility, reusability and quality. According to architect Eric Brusse, that means juggling a lot of things at once: “For example, measurement is a really interesting discussion from a designer’s perspective. It’s great if materials can be reused, but the existing examples are often mess. So sometimes you’ll have to add an extra plank, because the end result has to look good.”

“Once you’ve done this three or four times, you’ll see the unit price drop. And we’re noticing that more clients are contacting us because they know we can provide what they need.”
Martijn Icke, Heembouw Kantoren B.V.

Contractor Heembouw would have preferred to have come on board earlier, before the final design was available. It wasn’t until March 2020 that the contract for the renovation was signed. Until then, there had been an agreement on the programme and the budget, but the final choice of some materials hadn’t yet been made. This had consequences for the building process. Project Manager Jan Altorf: “We had to spend a lot of time making materials fit. With hindsight, this isn’t always circular. My advice is ‘stick to the materials you have and don’t go back to the pattern you had in mind.’” Waste is also something to take into account, adds Bianca Woutersen: “Where you just come across obsolescent dimensions, for example in roofing components, this often means sawing things down from the standard size. It’s good to take standard dimensions into account in the design phase.”

For the commissioning client, the sustainable aspect of the renovation has to be reflected in the end result, says Eelco Kienhuis, sales manager at SADC. “With this building we want to inspire our clients for Schiphol Trade Park, among other places. Even the reused window frames have to look good, so our clients say ‘Wow, is that really reused?’” Roeterink adds, “Schiphol Trade Park is home to business premises that are extremely sustainable. But you can’t always see that from the street – the sustainability is on the inside. In a way that’s a shame because the casual passer-by won’t know about it. We’re learning from this, and we now believe that sustainability isn’t just a story to tell, it should also be visible. Plants can help, but so can a green roof.”

None of the partners can give a definitive answer about what makes the perfect renovation project. Between them they conclude that the order and division of roles, leading or following, will be different for each project. It will always be a combined effort and need constant decision-making. Sometimes one party will have to step up and go beyond their initial role. For example, Eelco Kienhuis was good at getting on the phone to help track down materials.

Material scout
Everyone agrees that a new profession is emerging from this: the building material scout – the person who can find the right materials that are needed at the right time. It takes a lot of time and effort. “There’s no single database you shop from at your leisure,” Eelco says. According to Bianca, small-scale databases do exist. “There are supply sites for materials, with information about when they are available,” she says. And Martijn adds, “Knowing the market is also a big help. When I hear that something is being demolished, I always go and take a look.” Colleague Jan emphasises again why this is precisely why he likes to get involved in a project at an early stage. “Then we can also reuse our own materials. And more and more often we’re automatically being offered materials from other renovation projects so we can build up our own stock. When we were busy working on the renovation of the barn and our business partners knew that we were doing it circularly, we received regular calls asking if we’d still be interested in reusing materials – a floor for example. Of course, that presents us with a new problem. Where are we going to store it?”

How circular is circular?
Finding reliable, reusable materials is a major challenge, and so is using them in the building process. This raises the question: when it comes to circular principles, where is the boundary between circular thinking and action? How long can you really spend searching for sustainable building materials for a new roof? “If you take too long and deliver a project six months later, that’s not ideal either,” Martijn explains. “The decision to use a modular steel construction, for example, took a lot of time. In the end, we dived in the deep end by opting for Skellet and accepted the delay.” Martijn is now full of praise for a system that he didn’t know about prior to this project, and it has also been incorporated into a circular distribution centre they were developing. He does acknowledge, however, that due to interim adjustments that were needed, the modular work units aren’t completely circular. “If you have to invest to make something modular, that really has to be included within the initial price tag.” Skellet has already used its experience in Hoofddorp to improve the company’s product. And Heembouw has also developed a healthy screed floor, which is now ready for use.

“We had to juggle a lot of things at once.”
Erik Brusse, DOOR Architects

The flexible participation of those involved is essential for a broad transition to circular construction. The municipality of Haarlemmermeer, for example, was very flexible, Isaac says. “They issued an umbrella permit for this plot, valid until 2028, giving permission for the renovation provided the construction was demonstrably safe. And as soon as the constructor gave their seal of approval, we got straight to work.” In contrast, the subcontractors reacted differently, says Heembouw. The steel supplier was certainly enthusiastic, but the painter wasn’t impressed by our choice of sustainable paint. “He therefore refused to give a guarantee on the paint that was originally described,” planner Bianca explains. There is also no guarantee for some of the second-hand technical installations – but on the flipside, workers often went home really happy because they’d enjoyed the work so much. “We were able to sort out a lot of problems during construction. For example, the carpenter was able to be a real craftsman again. There was a lot of consideration and innovation on the work floor. It was really valuable.”

A voyage of discovery with spin-offs
The entire group acknowledges that the project felt pioneering. It was a voyage of discovery with a major financial challenge, which didn’t always yield the results they’d hoped for, but nobody involved has any regrets. What can’t be done today might be possible tomorrow. After all, circular building is gaining traction. “DOOR Architecten is a young company,” Erik says. “We always say, ‘you just have to do things’. By doing, we learn and we lead the way.” Heembouw has had a similar experience in the construction sector and says it will use its experience at C-Bèta in future projects. “Five years ago, there was really nothing like this, but the developments are speeding up. And we’re noticing that more clients are contacting us,” says Martijn. He’s also optimistic from a price perspective. “Once you’ve done this three or four times, you’ll see the unit price drop.”

For the time being at least, the partners expect that circular building is going to remain a niche business for the frontrunners. Commercial real estate still isn’t ready to embrace the transition. “Throughout this journey, we’ve had to make a lot of adjustments along the way. So you really need that intrinsic motivation to opt for circular building right now. As a commissioning client, SADC has gone a long way in this respect,” says Isaac. “We felt comfortable with it. We had a limited budget and a very ambitious plan, but by using the money intelligently we’ve ultimately achieved a really good result. At the core of this collaboration was the confidence that we were going to do something good. But with a traditional approach and division of roles, it would be difficult to get this kind of project off the ground.”

Box 1
The most important lessons learned from the circular renovation of the C-Bèta barn at Schiphol Trade Park

  • Ensure the design process is interactive and that the commissioning client, architect and contractor are included in all steps. This allows optimum adjustments to be made as the project flows.
  • The point at which the architect or contractor joins can vary per project. Deciding which party will take the lead is also a key question. But stepping beyond one’s own role from time to time can also be a positive.
  • Accept that the design can change as you go along. But do set boundaries in advance to maintain the pace: which elements are allowed to change, and which are not.
  • At an early stage, the commissioning client and architect should establish what materials are available and at what cost. Also consider that many circular products don’t exist yet. How long will you spend trying to source these materials?
  • Many things won’t fit into the architect’s plans. Leave space for free thinking; innovation also happens on the work floor.
  • Find cooperative partners who understand the value of innovation and want to go the extra mile – be that the supplier of materials, stairs, beams and panels, or even the municipality that issues the permits.
  • Consider not only how to source reusable materials but how to store them.
  • The business case should include concerns such as the amount of waste that will be produced. Keep thinking about how much waste will be produced and agree on a possible model to serve as a guideline: ‘we’ll make our decisions based on this…’.
  • Remember that there may be no guarantees for ‘second-hand’ materials and installations.
  • Appearances are also important. There is still progress to be made in the way people experience sustainability. Make sustainability visible.

Box 2
The use of materials and end result: light, inviting, playful and simple
What materials have been used and reused in the new barn at C-Bèta? The many windows in the façade and roof let in plenty of light thanks to the reused windows from the renovated Arsenaal building in Leiden – the farmyard and surrounding companies outside now feel like a part of the interior. The beams of the window wall had a previous life as support pillars in the former business premises of Aweta in Nootdorp. The new wooden window frames were made by WEBO from Rijssen using circular wood. Heembouw repaired the existing wooden window frames that were left over from the demolition of the barn’s exterior. Inside, most of the original concrete floor is still in place. The interior contains 14 modular rental units, one space for flex workstations, two meeting rooms and a business space – each with large windows or an open feel. The rental units are built using Skellet, a dismountable steel construction system made by the company ODS. Heembouw ‘harvested’ the frames and doors for the indoor units for C-Bèta during their demolition of the Centre Court office building in The Hague. A pitch corner was made from local wood from the Amsterdamse Bos. It also accommodates the pantry, which Heembouw salvaged from other projects. The floors of the units on the ground floor are insulated with b-grade sandwich panels. The upstairs units can be reached via reused staircases from former portable building units and cut to size where necessary. The sanitation facilities – sinks and toilet bowls – are also reused. Finally, the roof rests atop the barn’s original trusses plus one custom-made truss. Taken as a whole, this is a bright, inviting workspace for circular entrepreneurs, with an atmosphere of simplicity and comfort.

The following partners have also made a significant contribution: Vital Places (lighting), Degree-n (infrared heating panels), De Lange Natuursteen (tiles), Schuurman Technology (security system), JdB Groep (earthwork and exterior sewage), 123 Markeringen (floor signage) and SignMatch (signs).