All the crucial pieces were in place by 1970 to create the modern home pool/spa combination. Consumers, builders and manufacturers were clamoring to see vessels with more to offer than a simple lap swim or game of tag. While many homeowners had pools in their backyards, many more didn’t, and the hope was that certain enticements would turn this around.

The big news in pool construction for the 1970s was development of the inground gunite spa.

Spas had first appeared in the late 1950s in very rough form. With jets not yet available, the earliest spa builders fitted them with returns or made their own jets out of pipe, tees, nozzles and faceplates hand-cut from plastic. Builders found plumbing spas more complicated than the pools to which they were accustomed, with some early versions performing poorly from inadequate water volumes and the unavailability of high-head pumps.

Customers at first hesitated to attach these vessels to their pools because of unfamiliarity and expense: Builders might charge a premium to cover their expenses on these new and experimental projects. Attached spas confused some of the first owners, who had to open and close multiple gate valves to switch from pool to spa operation.

These early spas rarely changed the pool footprint: Builders simply built the hot-water vessel inside the cold. Spas were generally smaller than they are today, with a simple bench and two or three jets.

This new form of backyard entertainment and relaxation didn’t become widely understood and accepted until the ’70s. Once again, California blazed the trail, this time with its notorious hot tub scene.

The complexion of the industry itself began changing, too. The cluster of professionals originally hailing from such diverse industries as teaching, farming and landscape architecture ushered in second and third generations reared in the pool and spa business.

As the ’70s faded into the ’80s, builders looked for ways to make their projects look more interesting and work with shrinking lot sizes. Rather than leveling out tiny backyards and using retaining walls to handle elevation transitions, builders left the terrain as it was, yielding added visual drama from slopes and drops. Raised spas and raised bond beams became more common, with the added bonus of avoiding drainage problems.

New shapes added to the projects’ intrigue. Builders and clients wished to move away from the classic rectangles, now-rare ovals and ever-present kidneys. They began following the lead of landscape architects, whose goal often was to integrate pools and spas seamlessly into their environment using curvilinear and rectilinear freeform shapes. Two main directions developed for pool design — matching the pool’s architecture to that of the home, and fashioning a backyard getaway with such themes as alpine and tropical.

Stone was more widely available from stone yards, and more tiles than ever were produced for chemically controlled water environments. So, to assist in their design concepts, builders popularized these previously overlooked surfacing materials.

New interior finishes included dark blue and black plasters for a lagoon look. Pebble interiors arrived here from Australia in the late 1980s, and other exposed-aggregate systems — some flat and smooth, others resembling mini-cobblestone — followed in the early-’90s.

Fiberoptic lighting for pool applications began to appear in the early-’80s but began to take hold later in the decade. These low-power alternatives gave pools a distinctive look, winning raves from builders.

In the mid- and late-’80s, Lew Akins, then of Ocean Quest Pools in Austin, Texas, and Skip Phillips of Questar Pools & Spas in Escondido, Calif., popularized a design element that still wows consumers today: the vanishing edge. By reversing the spillway, they made water appear to vanish into the horizon at the edge of pools.

With all these tools at hand, the industry could address consumer concerns voiced in a historical survey commissioned by NSPI: The Oxtoby-Smith Report of 1990. This survey dispelled a common myth — that consumers make pool and spa purchasing decisions primarily based on price. When asking consumers their objections to pool ownership, they specified such things as maintenance chores and safety.

Shortly thereafter, analysis of the aging baby boom became the topic du jour for publications and telecasts. Studies found these consumers to be highly individualistic folks who desire creature comforts, often choose to stay home rather than vacation, and need meeting places in which to spend time with their children. They wanted pools — prettier, safer and easier-to-own pools than their parents had.

Manufacturers responded with new ways to ease pool and spa operation and cleaning, as well as safety devices ranging from door alarms to fencing, automatic covers to pool alarms. Builders then combined these new gizmos with new materials, shapes, multiple elevations and design elements such as vanishing edges and waterfeatures to add visual and auditory appeal.