As cities renew and become an increasingly attractive option to settle in, the problem with urban growth is that it inevitably sprawls outward, creating a whole host of issues, from inadequate infrastructure, waste management and more. One solution is to build up, rather than out, which developers in Barcelona, Spain are doing with the La Casa por el Tejado ("house on the roof") project, which installs lightweight, prefabricated apartment units on top of old, disused rooftops in the city. Fair Companies takes a look at how some of the apartments are installed in this video:
One interviewee, Gerardo Wadel of Societat Orgànica, explains why building on top of Barcelona's "forgotten rooftops" makes sense:
We've researched the square meters that are available. We found 2,800 buildings that can be built higher. That 800,000 square meters (8,611,128 square feet). This is a city on top of a city. We're trying to show that it's more sensible to build a city by taking advantage of existing structures and services. It doesn't make sense to build roads to get to cities 20 kilometers away. There's space for building here.
The units are designed for transport and division. Various pieces of the whole apartment are delivered onsite, lifted up by special cranes, and finished. Some fixtures are installed after the unit is put into place. From factory assembly to moving in, it can be as short as a few months.
According to the company, it spent four years doing studies and cataloguing the buildable air rights in Barcelona, and how to construct without disturbing existing residents of these buildings. As one resident explains in the video, air rights were then purchased by the developers, and the money given to these residents. These old buildings of the city -- many of them dating back a century -- were then given modern amenities like new elevators, green roofs, without any cost to the inhabitants in apartments below.
To make it possible, the builders have to remove weight from the roofs, such as old sheds, washing machines, etc., in order to "substitute" it with the prefab units, without having to alter the foundations. Making use of what is already there, and maximizing the vertical space, is a great way to grow cities in a more sustainable fashion. More info over at Fair Companies and La Casa por el Tejado.