When wealthy homeowners started having private pools built at their estates back in the 1930s or so, the pool area usually included a poolside structure just a few feet from the pool. Many of these pool houses were built to echo the architecture of the main residence. The primary purpose for a pool house was to have a "room" near the pool in which to change in and out of swimsuits, go to the bathroom, shower, rest, have a beverage and entertain friends or family in private.
Regardless of the reason pool houses may have been built, they still serve a purpose. A pool house can be a hideaway, a sort of outdoor office (with a roof and walls), a clubhouse and sleepover room for tweens -- whatever you desire.Pool houses are also attractive ways of harboring pool and spa equipment, which is often an unsightly elephant in the backyard.