Anyone who has read a lease or condominium association rules for a property in Paris has probably encountered a puzzling clause that reads: the occupant shall tolerate a raising of the roof.

What could this possibly mean?

Parisian property owners could increase the number of floors in their building. This was not accomplished by subdividing existing floors, but by adding new ones, constructed on the roof.

I don’t know whether this is still possible today, but for a few years it seems to have been a fad.

The most impressive example I’ve seen in Paris is a building on the rue de Rivoli.