A template for sustainable design

A new headquarters in the Netherlands has shown that a non-traditional approach to project delivery and a hands-on approach to sourcing material can pay dividends. Field trips to other countries to look at materials and an engaged team of sub-contractors, rather than a principle contractor, has resulted in what is being heralded as the most sustainable office in the world.

With a clear target of sustainability from the outset, the new headquarters for Geelen Counterflow features Cradle to Cradle certified products. This has resulted in not just a zero carbon building but it being awarded a BREEAM Outstanding score of 99.94%, making it the highest BREEAM scoring building ever.

Geelen operate in the feed and food industry designing and manufacturing complex cooling and drying solutions which use counterflow technology. With the challenge of drying processes that are notoriously energy intensive, the company is committed to helping the industry take a step toward phasing out fossil fuels through the development of electrical dryers that can run on renewable energy.

In light of this, Geelen wanted a zero carbon building for its new 2,800m2 head office in Haelen. They specified that it should generate at least the same amount of renewable energy as is used for ventilation, heating, cooling, hot tap water, lighting, computers and communication systems. Following research field trips, Geelen also specified construction materials to be ‘Cradle to Cradle’ or equivalent and the use of Lean/Smart construction principles.

For the outcome to be measurable and independently verifiable, BREEAM was prescribed as yardstick for sustainability, health and wellbeing. It was selected due to its wide scope, international reputation and facts-based approach. The fact that this building has reached the highest BREEAM score ever proves that sustainability and well-being were top priorities during the design and construction process.

A team of architects, technical consultants, BREEAM experts, and construction managers started a three year design process, constantly weighing technical possibilities against total cost of ownership and BREEAM credits. Instead of working with a principal contractor, Geelen worked directly with sub-contractors, with their activities coordinated by a construction manager who was recruited specifically for this project. This facilitated continuous improvement throughout the process, maximising the use of subcontractor know-how and experience.

This approach – virtually unheard of on such a large project – generated better results than expected. For example, rather than generating enough energy to operate the building a 50% excess generation of clean energy was created. It was also completed within budget.

Throughout the design of the building a Trias Energetica approach has been followed. This sustainability model is underpinned by the belief that for ecological as well as economic reasons, minimising energy use is essential before renewable energy is supplied. Detailed attention to insulation, thermal mass, thermal bridges, airtightness and daylight helped to drive down energy use.

Mass-timber

The most significant design decision came during a field trip of the design team to Germany and Austria in search of the most sustainable building material for the main structure, including its walls, floors and roof. The team selected mass-timber without adhesives in which multiple layers of timber are connected and held together by screws and beechwood dowels.

Such mass-timber provides excellent weight-to-strength ratio, dimensional stability, thermal performance, moisture management, fire resistance, acoustic performance, future flexibility and minimum waste generation. The system is ideally suited to industrial fabrication. Environmentally, the biggest benefit is the negative CO₂ footprint.

Further reductions in energy use were achieved by selecting a CO₂ controlled ventilation system which continuously maintains a small overpressure in each room, helping to evenly distribute air at low airspeeds. The improved comfort from low airspeeds and good air distribution allows a wider range of ventilation air temperatures which in turn reduces air volume and net consumption of energy.

Sizing of the HVAC system was not based on the usual 350 ppm of atmospheric CO₂ levels, but on the future 450 ppm that this office will probably be exposed to during its lifetime. Sufficient ventilation capacity was installed to ensure CO₂ concentrations inside can be kept below 800 ppm for maximum health and productivity.

Geelen has installed 330 solar panels of 327 Wp each, in East-West orientation, that generate 50% more electricity on an annual basis than office and staff consume. The excess electricity is used by the Geelen Counterflow factory next door for laser cutting of stainless steel, arc welding and for charging the batteries of electric forklifts. During weekends, excess electricity is supplied to the local energy cooperative whose windmills provide electricity when the sun does not shine.

Other environmental features in the building include solar heat collectors for washing and showering, LED lighting controlled by presence and daylight sensors and waterless urinals.  Rainwater is collected and used to flush toilets and water the green wall in the heart of the building. Triple glazing, tiles, carpeting and furniture are all Cradle to Cradle certified while rubber floors are recyclable. A garden surrounds the building and provides a haven for birds, insects, bats and frogs.

Commenting on the project, Sander Geelen, Managing Director of Geelen Counterflow, said: “We hope that this office will serve as an example to other construction projects. Energy-neutral construction in massive timber is just one of the ways in which we can make a small contribution to keeping our planet healthy for future generations.”

Winner of the new ‘offices’ category at the 2017 BREEAM Awards against some impressive international competition, this building proves that the transition to a sustainable, circular economy can improve comfort and wellbeing, as well as being economically attractive. BREEAM has provided credibility to Geelen’s claim of having designed and built an office that not only improves wellbeing and productivity of its users at low operational cost, but also makes a small, but important contribution to the health of our planet.