La Casa por el Tejado, a company specializing in the construction of old buildings, duplicated both the living spaces and the number of floors of an apartment building on Avenida Meridiana in the El Clot neighborhood of Barcelona. The new residences were built off-site in 12-weeks time and in accordance with the building's original dimensions and characteristics.
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This Off-Site Construction System Duplicates Floors in Barcelona Buildings in 3 Days
https://www.archdaily.com/913697/this-off-site-construction-system-duplicates-floors-in-barcelona-buildings-in-3-daysFabian Dejtiar