For the outcome to be measurable and independently verifiable BREEAM was prescribed as a benchmark for sustainability, health and wellbeing. BREEAM was selected because of its wide scope, international reputation and facts-based approach. The goal was 5 stars/Outstanding, or a minimum score of 85%.

A team of architects, technical consultants, BREEAM experts, and construction manager started a three-year design process, constantly weighing technical possibilities against Total Cost of Ownership and BREEAM credits. Geelen decided to work without principal contractor. Instead, all sub-contractors were directly engaged.

The company’s approach was 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.

Throughout the design of the building a Trias Energetica approach has been followed, underpinned by the belief that for ecologic 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.

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, walls, floors, roof etc. The team selected mass-timber without adhesives in which multiple layers of timber are connected by screws/dowels from beech wood.

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. One has to visit a wooden building to experience the warmth and comfort. Environmentally, the biggest benefit is the negative CO₂ footprint.

Further reductions in energy use were achieved by selecting a CO₂ controlled Ba-Opt 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.

This approach generated better results than expected, such as 50% excess generation of clean energy, a BREEAM score of 99.94% and project completion within budget. This building proves that the transition to a sustainable, circular economy can improve comfort and wellbeing, as well as being economically attractive.

Key environmental features

• HVAC primary heat exchanger with optional internal bypass

• HVAC secondary heat exchanger without bypass for toilets and copiers

• 8 closed loop brine-collectors of 112 meter deep

• 23 m2 solar heat collectors for washing and showering

• Two separate brine-water heat pumps to enable simultaneous heating and cooling

• LED lighting controlled by presence- and daylight sensors

• 10.000 litre rain water storage for interior green wall and flushing toilets

• Waterless urinals

• Triple glazing, Cradle to Cradle certified

• Recyclable rubber floors

• Tiles and carpets, Cradle to Cradle certified

• Furniture, Cradle to Cradle certified

• Bio-based, white roofing

• Ecological garden with facilities for birds, insects, bats, frogs

• Parking lot with reinforced grass and 4 chargers for electrical cars