Birdwatching hut Piilokoju

Area Planning – Architecture




Tourism area 2500 gross m2, Niliaitta prototype 36 gross m2 / 30 interior m2


City of Helsinki


Photographs: Archmospheres, Marc Goodwin | Video: Jussi Hellsten | Model: Antti Pulkkinen

Hiding in Nature


The newest addition to the Helsinki Vanhankaupunginlahti Nature Reserve, the Birdwatching Hut ”Piilokoju,” continues the accessible outdoor route designed and built in connection with the previous Nattours project. Piilokoju is intended for observing waterfowl, which are abundant in the Vanhankaupunginlahti area. 


From within the depths of Piilokoju, nestled between wooden slats, one can observe birds without disturbing them. The structure was designed in collaboration with Helsinki city environmental experts and bird enthusiasts to optimize its form and construction and minimize its impact on the surrounding nature.

Key objectives in the design were blending into the landscape, ecological sustainability, and a unified material palette. Our aim was for the bird hide to facilitate the appreciation and learning of nature, rather than drawing attention to the building itself.


The birds in the area feed in the reed bed wetland, making Piilokoju’s location ideal for bird observation. Visitors can hide among the tall reeds, disappearing from the view of the birds. Observers can see the birds, but the birds remain unaware of the observer.

The spruce wood structure blends into nature


Structurally, Piilokoju is a floating platform, a large wooden raft with concrete pontoons underneath. To preserve the sensitive natural environment of the Natura area, the hide was pre-built on the opposite side of the bay and then towed intact to its location.


The walls, floors, and roof of Piilokoju are made entirely from Finnish-grown oak, the same material used for the structures of the Nattours route. Oak is weather-resistant and ages beautifully over time. Some of the support structures also use spruce laminated timber aged with iron vitriol. The materials, along with the building’s unique form, allow it to blend in seamlessly with the natural surroundings. Inside Piilokoju, light filters beautifully through the slats, creating a serene and secure atmosphere.

Equal access to nature for everyone


A central goal of the entire Vanhankaupunginlahti area project has been to deepen the connection to nature for all people. Similar to the Nattours route, Piilokoju is also accessible to everyone. ’


Beyond physical accessibility, Piilokoju was designed to be an open and inviting space for everyone, not just bird enthusiasts. The hide can accommodate up to 40 people simultaneously, allowing for school class visits, for example. The adjacent waiting area can accommodate the next group, ensuring a smooth flow.

To make the journey to Piilokoju as easy and accessible as possible, the route includes passing areas where others can be overtaken effortlessly and safely. A fence at the entrance of the hide protects visitors from falling into the reeds. Construction work on the site has been carried out mainly by hand and using traditional methods, in order to minimize disruption to the sensitive surrounding nature. The support pillars for the accessible route, for instance, were hammered into place using manual tools.


Co-designed to meet the needs of bird enthusiasts


In addition to consulting with nature conservation experts, we have actively collaborated with bird enthusiasts to ensure that the hide caters to their needs as well. The shape and openings of the building have been optimized for larger groups, enabling those seated in the front to have a view of the outdoors even from the back of the hide. 

The interior height of the hide only extends where necessary, sloping towards the edges to naturally integrate it into its surroundings. The fixed furnishings have been optimized for observing and photographing birds. Birds can be observed and photographed while standing, sitting, and even lying on the floor at water level, thanks to carefully placed openings in the glass surface that prevent disruptive reflections.


The primary direction of bird observation is toward the northwest, where the mudflats are located. Piilokoju also features hatches that open to the northeast and east, allowing for observation of the sea eagle’s nest on Loppi Island and the birds on Vanhankaupunginlahti Bay. The benches at the back of the hide provide a place to rest and simply enjoy the tranquility.


The Vanhankaupunginlahti project continues, with the next step being the bird watching platform that we have designed on the opposite shore, Hakalanniemi, set to be completed in autumn 2023.


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