The proposal Koota developed by OOPEAA to be realized in collaboration with the Tila Group wins the competition for a new wooden housing block to be built in the West Bank of Porvoo, a small historical city with a significant heritage of wooden buildings from the 19th century. Located on a river delta by the coast in southern Finland, Porvoo offers great quality of life and a small town atmosphere within a convenient commuting distance from the metropolitan Helsinki. Koota seeks to provide a contemporary addition to the tradition of wooden housing in the growing city of Porvoo. It creates a new solution for urban living in a way that is both ecologically and socially sustainable and promotes a sense of community amongst the residents.
An Urban Village
The composition of the Koota block is designed around the concept of an urban village. The scale is at once deliberately urban, yet not very high in density. It provides a sense of community while also emphasizes strong links to the surrounding context of the city. Building a sense of continuity with the existing urban structure Koota facilitates the growth of the city in a way that maintains the small town identity of Porvoo. The block is composed of several buildings that together form a village-like whole. It provides a varied mix of residential spaces, shared communal facilities, commercial and office space, and open outdoor areas.
The scale of the buildings varies from smaller townhouse-like buildings and row houses to multi-story apartment buildings bringing a range of different kinds on living together in a lively and multifaceted neighborhood that serves a community of people of different ages from single dwellers to families. The buildings lining the street are low and long. There are taller apartment buildings placed in the interior part of the block as well as townhouses and row housed with a smaller scale that offers an opportunity for a less urban style living with a private yard space attached to each unit. The ground floors are activated to facilitate a lively urban community. On the street side there are spaces reserved for various kinds of commercial activity from office spaces to cafes and retail spaces. On the courtyard side there are communal facilities for shared use by the residents, including a sauna, a workshop space for fixing bikes, laundry facilities as well as spaces for meetings and hobbies. In the interior courtyard there are generous open garden spaces for the shared use by the residents.
The apartments range from duplex apartments with lofts in the upper floors to more traditional apartments on just one floor and to atelier-type apartments with two floors and a direct access from the yard. Each apartment has a balcony or a small yard of its own. The balconies form an intermediary zone mediating between the public and the private. Through the balconies the daily life is also present in the image of the block adding its own color and character to it. They also provide shading to shelter the interior spaces from too much direct sunlight.
The varied roof shapes give the buildings character and give the block a clearly identifiable architectural expression and a unique identity of its own. The roof scape intentionally creates an association with the traditional picturesque wooden towns linking the block with the historical heritage of the city of Porvoo. While the shapes of the roofs take reference from those of the Finnish tradition of building in wood, they have been realized with a fresh modern touch making use of contemporary methods and in a way that responds to the needs of today’s dwellers.
A Modular Structure of Mass Timber
All buildings in the Koota block have a CLT-based structure of massive wood and the façade material is also wood. The primary load bearing structure in all buildings is composed of prefabricated volumetric modules with all walls, flooring and ceilings made of CLT. Also the elevator shafts as well as the flooring of the hallways are made of CLT, while the foundations and the basement level are of concrete. The structural solution is based on volumetric modules made of CLT. All piping for water, air and electricity is integrated in the wall between the individual apartment units that come fully prepared from the factory and the hallway that is constructed on site. This makes it possible to keep the CLT-modules clean during the construction phase as well as to update, change and repair the system without any need to gain access into the apartments.
The use of prefabricated volumetric modules made of CLT is both economically efficient and ecologically sustainable. The technique of building with volumetric modules is based on the principle of making use of the potential of an advanced level of prefabrication under controlled conditions in a factory. It makes it possible to cut down the on-site construction time bringing significant savings in the cost construction. It also makes it possible to control the humidity and moisture during the process of production and preparation of the modules and helps to minimize the noise and dust caused by the construction site.