NIOO-KNAW, Wageningen The Netherlands

NIOO-KNAW building © Froukje Rienks


In the construction of the new building of the Netherlands Institute of Ecology (NIOO), attention was paid to sustainability in all areas. Thinking in terms of natural cycles and studying ecosystems are NIOO’s core business. The choice was therefore made to create a building according to the ‘cradle to cradle’ (C2C) system. In this approach, the aim is for a building to fit as harmoniously as possible into the natural environment and to contribute positively to it. This philosophy goes beyond energy efficiency. It also looks at the use of materials and the ecosystem as a whole.  When building according to the C2C principle, use is mainly made of renewable raw materials that cause no environmental damage in the chain of extraction, processing, use, and the waste phase. Preferably, the materials should be reusable.

The design incorporates sustainable energy generation in the form of high-temperature heat and cold storage and solar energy. Sustainable building materials and a sustainable construction method were chosen. Of course, much attention has been paid to strengthening local biodiversity. Water, including waste water, is processed locally.

The complex consists of a main building with laboratories and offices, and several annexes. It accommodates around 170 workers.

Reason and context

The Netherlands Institute of Ecology (NIOO), one of the research institutes of the Royal Netherlands Academy of Arts and Sciences (KNAW), studies the impact of nature in all its forms. Worldwide, ecosystems are threatened by an increasing demand for food, fresh water, timber, fibre, and fuel. Biodiversity is being lost at an alarming rate due to growing economies that ignore this degradation. There is an increasing need to change from a consumptive economy to a circular economy.

To this end, the NIOO works closely with other organisations in this field, such as universities and knowledge institutes, and also conducts its own research. When the NIOO decided to merge two of its locations, an opportunity was provided to expand its research facilities and to choose a location for the building closer to the locations of the organisations it works with. Wageningen University (WUR) made over four hectares of its land available for this new building, close to the campus and at the heart of Wageningen’s green knowledge centre.

NIOO ecologists strive for sustainable innovations inspired by nature. The new location gave NIOO the opportunity to incorporate these innovations as much as possible in the design of the new building and to experiment with them. They set up programmes to gain experience with their application and to monitor them over time.

© Perro de Jong

Process and cooperation

The NIOO-KNAW deliberately did not choose ‘green’ companies when selecting the architect and construction company. For the architect, the choice fell on Claus en Kaan Architecten, a firm known for its sleek and minimalist designs. This is to ensure that sustainable building also lands in the traditional building and real estate world. supported the design team by contributing knowledge in the various fields of sustainability and by obtaining grants for innovation.

Contributing to the good results in the area of sustainability was the tenacity of NIOO as co-commissioning authority. It was also stressed from the outset that legal perils in the process were to be avoided. To prevent these, a process supervisor was specially deployed.

It was a learning process, as some of the team members had no specific experience with sustainable building.

Description of the design

Claus and Kaan Architecten deliberately designed a compact building, in which laboratories and offices are located next to each other, so that walking distances remain short. The main layout is spacious and offers plenty of room for informal meetings. Voids provide connections between the floors and bring daylight deep into the building. The spacious layout of communal functions such as the canteen and colloquium hall are intended to promote a relaxed and inspiring working atmosphere.


The building uses High Temperature Storage (HTO) for the first time in the Netherlands. This technique is similar to the usual Heat and Cold Storage (WKO) in which heat and cold are stored in the ground a few (tens) of metres below ground level. With HTO, water is stored in deeper, porous soil layers (300 m). The heat is produced by 116 (478m2) solar collectors in summer and used again for heating in winter. Besides solar heat, the HTO also stores excess heat from the building and greenhouses. The HTO is supplemented with WKO and a heat pump when needed. The stored heat is brought inside (concrete core activation) through pipes in the floors. These installations save 70-80% of the energy for heating and cooling. HTO is still new and quite expensive in the Netherlands; it was a pilot when the building was constructed. The system was monitored for 5 years and also serves to provide further knowledge about this new technology. A WKO installation alone would not have been sufficient for the NIOO building with its high energy heat consumption for laboratories and test greenhouses.

The shed roofs of the voids and the flat roofs of the outbuildings were fitted with solar cell foil integrated into the roofing. This was another pilot to investigate which product yields the most energy. At the foot of the earth embankments, 200m2 of Sun Cycle PV panels were applied, also a pilot to investigate whether these panels containing lower amounts of rare metals also deliver the predicted improved efficiency.


The NIOO building has overhangs and screens; in practice, the overhangs keep out the summer sun but do not sufficiently screen out the winter sun. In well-insulated buildings, more attention should be paid to shading year-round. The plan is to consider photovoltaic glass when renewing, which uses some of the sunlight for energy production and thus also keeps some of the heat out of the building.

Natural ventilation

A hybrid ventilation system has been installed. The design provides for natural ventilation and mechanical ventilation based on CO2 detection.


The NIOO building has been optimised with regard to lighting. There are motion detectors and daylight detectors for switching off the lighting when no one is present in the room and controlling the brightness depending on the amount of daylight present. Furthermore, the entire building is fitted with energy-saving LED lighting.



Claus en Kaan Architecten had to meet a number of strict requirements regarding the choice and processing of materials.

The desire to build according to ‘cradle to cradle’ principles demands that, if possible, all parts of a building can be disassembled in the final phase of their life cycle and reused in a valuable way. NIOO’s architect addressed this by choosing as many pure, primary building materials as possible that lend themselves well to reuse. It was also important not to use glued or composite materials; these do not re-use well.

The materials used in the NIOO building are mainly:

  • Steel
  • Minimal use of plastics, sealants or foams
  • Glass
  • Non-chemically preserved (Plato) wood and FSC-labelled wood
  • Concrete with rubble aggregate and low Portland cement content (i.e. more blast-furnace cement)
  • EPDM roofing (recycled car tyres)
  • Mostly flax, cellulose or sheep’s wool (around air ducts) as insulation material
  • No epoxy floors, but polished and environmentally-friendly impregnated concrete floors

The shell is made of durable concrete without artificial additives, sealants, solvents, or the like. A concrete building skeleton was not the first choice on C2C grounds, but proved necessary due to the high steel prices at the time and the stability requirements (building vibrations) of the laboratories.

The use of products bearing quality marks such as FSC- and PVC-free certified materials was taken into account. The use of materials such as wood, glass, steel, crushed limestone, and granular rubble creates a streamlined building with an open and natural feel.

Particularly successful was NIOO’s ambition to use no toxic building components and materials during construction, and to reduce the use of sealants and foams to virtually zero. Excluding toxic building components posed few problems. The construction parties involved did their best to think along these lines, with some new discoveries being made. In general, much of the toxicity has already been eliminated by using pure, primary building materials, because the culprits are mainly in paints, finishing layers and composite materials. Construction encountered additional problems when installing the kilometres of electrical wiring in the building. At a very late stage (during execution), it came to light that common cable sheathing contained halogenated hydrocarbons (flame retardants). The NIOO found this unacceptable, and a different cabling was then eventually chosen (polythene with a fire-resistant, halogen-free compound).

Sealants, foams, and glues are also often toxic and tend to contaminate the primary building materials they are bonded to, making dismantling and recycling problematic. Through enhanced detailing of the shell construction and finishing, the use of sealants and foams can be reduced by at least 80%.


One of the project’s aims was to show that waste is raw material, using the water cycle as a basis. The goal was to avoid connecting the building to the sewerage system. Because of the connection obligation, this was not achieved; the water board did not want to take this risk.
A sewer was therefore constructed, but it was agreed that if the realised systems proved to be satisfactory, it would not have to be used. In the field of wastewater treatment as well, some experiments were chosen.

Human wastewater consists partly of risky pathogens, drugs, and hormonal substances, but also nutrients, water, and a variety of other useful or less useful substances that are lost through the sink or toilet. Only the most advanced (expensive) sewage treatment plants extract many useful substances from wastewater, including phosphorus compounds. Phosphorus is a finite and irreplaceable resource and as a fertiliser, crucial for food supply.

Human wastewater (urine and faeces) contains a lot of phosphorus from the food we have ingested. Through a normal sewage system, phosphorus disappears into the environment (often eventually to the sea) in a way that we cannot recover. Thus, the world needs small-scale, cheap, and simple methods to locally extract phosphorus from wastewater. This is where NIOO wants to contribute, and what better way than to use its own wastewater as a test bed?

The NIOO is building a system on its own site to purify wastewater in such a way that the useful nutrients are fully utilised and the effluent can be discharged without any problems.

The system starts with vacuum toilets that consume only 0.5-1.0 litres of water per flush (groundwater in the case of the NIOO), minimising faecal dilution, a unique concept in an office building. The biomass then goes to a digester, where part is converted into biogas as an energy source. The final stages of water treatment consist of an algae cultivation system and a helophyte filter. In the algae reactor, the algae grow and absorb nutrients, including phosphorus, from the water. The NIOO and WUR are studying this ability of algae to purify water (human pathogens, pharmaceutical residues, and metals). Harvesting the algae recovers valuable minerals such as phosphates, for example, for use as fertiliser in agriculture. If the process goes well, the remaining water can be post-purified by the existing helophyte field and infiltrated into the soil. Incidentally, the pilot plant is too small (using only its own wastewater) to harvest algae commercially. Together with research partners, the NIOO will monitor the setup for years and adjust it. It is expected to gain important lessons from it to make the process market-ready.



The aim was to fit the NIOO building well into its surroundings and provide space for a natural habitat. This has largely succeeded.

The old alders (which were in bad shape) and trees that had to make way for the construction will be brought back elsewhere on the site as wooded buffers. The site is surrounded by ditches and an earth embankment on which an assortment of native herbs, plants, and shrubs have been sown or planted, with a thorny woven hedge as ‘barbed wire’. A cellar has been dug into that embankment for bats. The bicycle shed will serve as a bee hotel for endangered solitary bees.

The large green roof of the main building displays a wide variety of sedum, herbs, and other vegetation, and the rainwater pond near the entrance already contained frogs before the new building was completed. It makes for an extraordinary spectacle: the ultra-stylish building of glass and wood, amid shrubs, butterflies, birds, herbs, trees, insects, and bats.

© Bouwbedrijf Berghege

Part of the roof is specially equipped for experiments and measurements. Experiments can be conducted with types of plants, the substrate, temperature, and moisture. The biodiversity generated by these plants (insects, birds) is studied by ecologists. How much rainwater the various vegetations capture and evaporate (thus buffering runoff to the sewage system in case of heavy rainfall) is also measured. And sensors in the concrete under the roof are being used to measure what different vegetation does to the insulation of the building. All this is done in close cooperation with green roof suppliers, hydrologists from Wageningen University, ecologists from NIOO, and the water chain.

But NIOO is going a step further. Together with Wageningen University, it is investigating how green roofs can contribute to variation in plant and animal species. The Ministry of Agriculture has awarded NIOO-KNAW an incentive prize to develop this project. In it, saving endangered plant species as listed under the European Habitat Directive is central. At the same time, experiments are being conducted to generate energy from living plants. Outside the building, biodiversity is promoted in various ways together with organisations such as Hedge and Landscape, the Butterfly Foundation, and the Bird Protection Society.

Learning points

 Construction process

  • Management must continue to put its full weight behind it
  • Realistic costing paves the way for a sustainable outcome
  • Capitalise planned savings from energy measures to invest them now
  • Need for a full-time user contact during construction
  • Some forms of procurement lend themselves better to sustainable construction
  • Aesthetics and environmental performance can be combined, up to a point
  • The Technical Design is also the crucial phase for sustainability
  • Communication and trust instead of legal jousting

Integral building quality

  • Sustainable building design is an ongoing quest
  • Architect finds the pure middle ground between sustainability and modern design
  • Some buildings can continue to evolve in sustainability


  • Energy storage ‘in between geothermal and CHP’ has great future
  • Combining CHP with HTO can lead to more than 70% savings
  • Construction is now (almost) entirely possible with LED lighting
  • NIOO promotes itself as a testing ground for new solar energy
  • Commercial buildings cannot yet do without purchasing green energy
  • External sun screening still easily overlooked

Raw materials

  • Building with only primary building materials is already halfway to ‘cradle to cradle’
  • Creating beautiful buildings with sustainable FSC wood is no longer a problem
  • Steel frames are preferable to concrete but not always feasible
  • Building with eighty percent less sealant or toxic materials is now feasible


  • NIOO building hosts innovative partnerships
  • Sewage becomes a source of fertilisers and bioplastics


  • New buildings can sometimes really help nature move forward
  • How to prevent a sedum roof from consisting of moss after 7 years
  • There is an ecological alternative to fences and barbed wire (the woven hedge)

Sources consulted:

NL Agency, M. v. (2011). A building that lives Lessons Learned new construction NIOO. Utrecht: Agentschap NL.

NIOO-KNAW. (2011). A building that breathes life. Wageningen: Royal Netherlands Academy of Arts and Sciences (KNAW), NIOO-KNAW.

Power from plants

Plant-e B.V.

Local water treatment

NIOO-KNAW Aquatic Ecology

WUR-Environmental Technology

Water Board Vallei and Eem

Ingrepro (algae)

Landustrie/DeSah BV (vacuum toilets)

Ecofyt (Helophyte filters)

Biodiversity/site design


Stichting Heg en Landschap

Koninklijke Ginkel Groep

Wagenings Milieuoverleg

Dutch Butterfly Conservation

Netherlands Society for the Protection of Birds