In 2008, Leonardo DiCaprio bought into a Manhattan building with solar power and filtered air; 6 years later, he bought the neighboring apartment for $8 million

Leonardo DiCaprio has spent decades talking about the environment. His Manhattan apartment reflects that interest. The actor bought an apartment inside Riverhouse, a 32-story tower in Battery Park City built around solar panels, twice-filtered air, and its own water treatment system, for $3.67 million in 2008, according to CityRealty. Six years later, he came back and bought the unit next door for $8 million. The purchase comes at a time when research has increasingly highlighted the importance of indoor air quality: Harvard T.H. Chan School of Public Health's COGfx research series has linked better-ventilated, green-certified buildings to higher cognitive test scores, improved sleep quality, and fewer sick-building symptoms among occupants.

A green tower with famous neighbors