The Simbcity housing prototype by the Spanish Plateau Team has been developed to solve a real challenge for cities: how to achieve the total energetic refurbishment of the outdated housing estate and transform it into an affordable and socially sensitive alternative for the building industry. By retrofitting existing inefficient and decaying buildings, the team's entry into the Solar Decathlon Europe 2014 adds a near-zero-energy upper storey, and renovates the existing building up to a minimum level B energy rating.
Taking inspiration from the natural phenomenon of symbiosis, Plateau Team proposes “the colonization of the roofs of the target buildings with an extra level of construction.”
The additional level can be put to a variety of uses, including public facilities and residential dwellings.
The proceeds of selling the upper level’s development are then used to fund a global refurbishment of the rest of the building.
The team describes this as a mutual benefit between “host” (existing) and “guest” (new) housing units, and the symbiotic relationship model guides the whole project: from the finances and construction principles, to energy and equipment sharing.
Simbcity begins with an external wooden structure added to the existing building.
The structural system creates an extra, one meter wide space for the host housing units. This increases the building’s surface area and creates an air chamber where heat from solar gains can be stored, reducing heating consumption in winter.
Following a standardized plan, three main areas are constructed for the addition. The first is the main room where daily activities take place, the second room is a multifunctional space that doubles as a patio or greenhouse according to the season, and the third space contains facilities and wet rooms.
The extra level does not sit directly on top of the existing roof. Instead it hangs from the wooden bracing structure without intermediate supports, transmitting all the structural charges directly to the ground. This feature is especially important to ensure the addition doesn’t interfere with the use or structural integrity of the host building.
The team identified the abandonment of traditional cities due to uncontrollable urban sprawl as the main challenge that European cities must now face. They say that "In Spain, the suburbanization phenomenon is a huge energy, pollution and mobility issue, especially in the Madrid metropolitan area."
To combat this, the team's approach "has been thought from our own local context, focusing on the buildings and social groups which most need refurbishment operations and energy savings, in our case, [this is] the large housing stock built from the 1950s around Madrid, which need urgent refurbishment operations."
The main challenge of the Simbcity project, however, is to generate all the energy demanded by the house from solar power, and generate a surplus to feed the housing underneath.
The Plateau Team is composed of 40 mostly undergraduate students from Universidad de Alcalá de Henares and Universidad de Castilla-La Mancha in Spain.
The Simbcity prototype is a complete housing unit with a 1.3 meter deep basement representing the “host” building.