For this remodeled San Francisco Bay Area home the pool plaster was slightly colored gray to add reflection to the water's surface, Robert Mowat's homage to Thomas Church, who liked to add a bit of lampblack to his pools to achieve this affect.

It didn't take long for this dynamic, professional couple and their active family of five to outgrow their house. Moving away from their beloved suburban Northern California Bay Area community, however, wasn't an option in their book. They scoured their quiet town until they finally found a lot featuring a small, dilapidated 1940s cottage that stood 60 feet in elevation from the street. Despite the state of the house, the tree-filled property and its views of surrounding foothills and lush vegetation convinced them to make this place their new home. And so, the couple decided to take on a full property remodel, turning the cottage into an Italianate hillside villa.

A valve controls the water cascade, from a sheet to a trickle.

The original foundation had to be left fully intact, constrained by the city's requirements of building footprint ratio to lot size. This left the home's rear yard with no usable space. A steep 30 percent slope, rising 19 feet, began directly just outside the back of the home. Through a series of design concepts presented by the landscape architects and refined by the clients, a design was created where a water feature would be the main social space, revolving around a pool and spa complex located at the top of the slope, 13 feet above the home's back doors.

To make room for a spa, a belvedere was built to extend toward a two sided fireplace, providing entertaining spaces on three different levels within the confines of the small rear yard. Magnolia grandiflora "Little Gem" and Rosa spp. "Simplicity Red" are among the pool plantings.

To put the plan in motion, Robert Mowat Associates sculpted and carved out the hillside. The team created four separate patio levels centered on a two-sided fireplace and dramatic invisible-edge pool. The pools and patio take full advantage of the impressive views of the hills. From above, the pool creates a dramatic invisible edge that carries over into a kinetic wall of water to offer relaxing, ambient sound. After selecting the design, the landscape architects quickly collaborated with a structural engineer to ensure the cut slope of the design did not disturb a neighbor's higher elevated pool, situated a mere five feet from the property line. The timing of the new retaining wall construction and pool would have to be done quickly and in the dry season, with no chance of land subsidence. A separate consulting engineer ascertained a six-foot cut into the slope and a new pool would not affect the neighboring pool's foundation or create any future unwanted settlement.

The lower basin wall doubles as a seating area on the upper flagstone and lawn area. The sights and sounds of the water wall are prominent from the dining room.

The engineer's solution was a grid of piers 16 inches in diameter, placed six feet apart and sunk 15 feet into the ground. An 8-by-12 inch concrete "T" beam ties them together and to the pool shell. The grading cut of the slope and pier excavations went smoothly; no wet weather was encountered. The pool excavation, forming and gunite placement were then quickly implemented. During construction the contractor erroneously eliminated a surge tank designed to ensure enough water was available for the waterfall feature to function properly. The landscape architects, anticipating such a mishap, designed the lower basin with enough water capacity for the water feature to function as envisioned.

The water-washed flagstone is seen from the patios below and is heard from inside the home with the French doors open. The waterfall basin has a precast concrete cap that acts as a seating area next to a lawn and an upper level fireplace. A fourth level has a lower level fireplace and a dining area that looks out to the nearby hillsides.

Landscape Architect: Robert Mowat Associates www.RMAlandscape.com • Architect: Tim Haley, Impluvium Inc. www.Impluviumarch.com