Simply put, the Client wanted to know if a swimming pool could be built in the space that was occupied by a large level deck that you walked out onto from the inner corner of their L-shaped house. Straight out this door, beyond the deck area, was a new concrete pad where the Clients wanted to put their new spa.
An inspection under the deck revealed a temporary type of concrete footings, so the existing deck & sub-structure was abandoned, and replaced with a permanent wood substructure with posts anchored to reinforced footings. A synthetic decking was selected to try to match &/or complement the color of concrete already selected and approved for the cantilever pool deck and pool cover vault lid.
Then borrowing a trick from architects, the outer edge of the catwalk slightly overhangs the wood retaining wall with a face of redwood rough 2x6s connected horizontally to the new posts and painted black to serve as the dark recesses between smooth S4S redwood 2x4s stained to match the Step risers and installed over the black 2x6s for visual contrast. Steps lead down to the deck, as well as to the new spa pad at one end, and to the pool vault, and then down more matching steps to the hidden pool equipment and lawn and play equipment beyond.