[1] European designers and architects long recognized the potential in creating living spaces that could make use of rooftops and such setbacks.
Its success caused a rapid development of similar luxury penthouse apartments in most major cities in the United States in the following years.
[2] The popularity of penthouses stemmed from the setbacks allowing for significantly larger private outdoor terrace spaces than traditional cantilevered balconies.
Due to the desirability of having outdoor space, buildings began to be designed with setbacks that could accommodate the development of apartments and terraces on their uppermost levels.
They may also have such features as a terrace, fireplace, more floor area, oversized windows, multiple master suites, den/office space, hot-tubs, and more.
Penthouse apartments are considered to be at the top of their markets, and are generally the most expensive, with expansive views, large living spaces, and top-of-the-line amenities.