The passive solar roof penthouse addition to the third floor of a three unit apartment building was a design/build project in Chicago's Lincoln Park area. 

A concrete deck over steel joists finished with tile provides the mass for holding the sun’s energy.  Trees on the west provide summer sun protection.

The addition provides a direct solar gain sitting room, a bathroom and dressing room adjacent to an existing fourth floor bedroom, increasing the size of the combined third and fourth floor living unit.

A cedar louvered overhang shades the interior from the summer sun.