The Tree House / Baumraum © Markus Bollen Architects : BaumraumLocation : Hechtel - Eksel , BelgiumArchitect In Charge : Andreas WenningYear : 2012 Photographs : Markus Bollen © Markus Bollen Sappi , The Flemish Forest and Nature Agency , the commune of Hechtel - Eksel and Proximity joined forces in a unique partnership to stimulate companies , politicians and organisations to embrace sustainability in their daily activities . What better way to do this than to build a treehouse ? According to the international paper producer Sappi , which started the project with Proximity BBDO , their communications agency , a treehouse would make their sustainability efforts more tangible , more real , and a true source of inspiration for others to follow . © Markus Bollen The Flemish Forest and Nature Agency and the commune of Hechtel - Eksel , were quickly sold on the idea to create this project on their premises and enthusiastically embraced the concept . © Markus Bollen All with one vision : environmental quality and social responsibility for the benefit of people , planet and prosperity . THE TREEHOUSE helps to bridge the gap between economy and ecology . © Markus Bollen THE TREEHOUSE isn ’ t just any treehouse . It ’ s a small architectural wonder equipped with state - of - the - art eco facilities located in the forests of Hechtel - Eksel © Markus Bollen THE TREEHOUSE is the ideal place to hold break - out sessions where businesses can brainstorm about the importance sustainability to their company and ways they can improve to build a better future for the planet . It is the perfect location for scientific research and relevant presentations . © Markus Bollen How is THE TREEHOUSE designed ? The major image of the design is a sheet of paper that is pleated and encloses both interior and exterior spaces . THE TREEHOUSE is based on five elements : two cabins on different levels , connecting terraces , a staircase and a connecting roof . © Markus Bollen In the lower cabin is a coffee lounge , pantry , restroom and technology room . The upper room is dedicated to meetings and other events that are appropriate to this exquisite space among the trees . Benches covered with soft pillows surround the space resulting in a comfortable and laid - back feeling , encouraging one to stay longer . © Markus Bollen The cabins and upper terraces rest on 19 angled steel stilts . Each steel stilt is connected to the ground below with foundation screws that have a minimal impact on the forest floor . © Markus Bollen All equipments use the existing supplies ( green electricity and water purification ) of the nearby museum or are selfsufficiently ( heat pump ) . The newest techniques are used for the heating and cooling system . A heat pump unit which is situated in an underground space , extracts heat from the air . The warmth is transported through tubes which are led through one of the steel columns into the cabines . After converting the warmth to a fluid , tubes will transport it to the heating - units under the benches . The result of this low temperature heating system is a nice , comfortable climate and the energy cost remains very low . In summertime the system can be used for cooling as well . This system is CO 2 neutral . The balanced ventilation system is totally demand - based with supply and abstract units integrated in the benches . The ventilation and heating systems are continuously monitored . To minimize the energy consumption , all lights are LED . In the toilet , daylight - and movement - sensors are integrated in the LED armatures .