In the Netherland's Eem Valley, NarrativA architecten has designed a carbon-negative observatory for an ecological farmstead that combines biophilic design with passive principles and bio-based materials. The Natuurobservatorium de Eemlandhoeve, replete with a green sedum roof that makes it merge with the landscape, is reminiscent of a mushroom with gills—the challenge, the architect's explain, was to structure the building's organic form onto a simple grid so that it could be built relatively easily and inexpensively with the community.

Design

The organic shape of the observatory evokes that of a mushroom. Rather than creating a shape as a freeform curve, the architects constructed it from 12 straight roof sections, each angled at 30 degrees. Together, these sections approximate the mushroom-like form while creating a simple, repeatable structural system. 

Floorplan

The nature observatory consists of an entrance hall with an impressive spiral staircase, an exhibition and meeting space for approximately 40 people, a quiet room, sanitary facilities, a small meeting room on the first floor, and a covered observation tower. This viewpoint, at a height of nearly 8 meters, can be reached via the wide circular internal staircase in the core of the building or via an external staircase.

Green roof

The building is completed by a green roof that is covered with various sedum succulents, herbs, and wildflowers, that together promote the region's biodiversity in the fight against global bee and butterfly mortality. Additionally, the roof offers extra insulation against the hot summer sun. From the panoramic view, the roof forms a single green oasis together with the surroundings, as if you were standing on a hill in the landscape.

Materials

The building has been constructed with bio-based materials and passive house strategies that together help the site achieve an optimal indoor climate. The structural frame is made from glulam that is built upon a concrete slab foundation. The walls are built from 36cm thick hempcrete blocks (IsoHemp), that are completed on the exterior with breathable lime plaster. Inside, the walls have been finished with interior clay plaster that naturally regulates humidity and temperatures throughout the year.  

Construction

The building was constructed in phases. NarrativA architecten was responsible for the design, Bouwbedrijf Van Engen for the construction of the solid, watertight structural shell, and the remaining interior and exterior finishes are being completed in stages by skilled volunteers from the Eemlandhoeve community. The building is designed to support a wide range of social functions, among them: healthcare, education, exhibitions, retreats and meditation.