Building new homes on top of an old city

WITH population growth causing problems for big cities all over the world, a company has come up with a new way to tackle the overcrowding and extend Barcelona in a different way: upwards.
Madrid-based developer La Casa por el Tejado – House on the Roof – (LCT) has come up with a plan which is proving increasingly popular in Barcelona’s bustling Eixample district, which basically buys up available air space above existing buildings and drops pre-fabricated penthouse flats on top.
 LCT realised that in the past, cities tended to extend by sprawling outwards rather than upwards, meaning in many cases buildings are perfectly capable (and permitted) to add another floor or two, which will allow more homes to be built without the need to use up undeveloped land and create infrastructures to support them.
The first step is to buy the air space, then buildings are primed by installing lifts, redoing facades and other work needed to adapt them to the new addition while also improving surroundings for existing residents.
Meanwhile, the flats themselves are built at an off-site factory with plumbing, electrical installations and flooring built into the units.
Once ready, units can be shipped in and placed on top of the building in as little as one day.