Because many people have little exposure to woodworking and the manual trades, the process of creating finished furniture from a stack of rough lumber often seems mysterious.
For many custom projects, more than half the work is done not inside the shop, but on the computer (or with pencil and paper for some people). Up front planning minimizes time spent on the shop floor and reduces the chance for error. Before any wood is cut, every part is created and fit together inside the drawing and potential issues are resolved.
With these pews it was quickly apparent that the two biggest issues were the arms and the kneelers (due to the unique parallel arm action).
A simple fact that is known to woodworkers is that wood constantly expands and contracts as the humidity changes. The expansion is not equal in all directions though. It is primarily across the grain and almost non-existent along the length.
Using a stable panel in the center with solid wood edging all the way around is the ideal solution here. This gives the durability of solid wood to all the corners but stability similar to that of plywood. Those long, narrow rectangles laying across the joint represent screws and let me know what length of screw works best.
The kneelers were the most time-consuming aspect of the entire design. Prior to building anything, the entire action was modeled in a computer drawing and the motion tested to ensure proper function. Finally, a full-sized mockup was built.
Testing with the mockup made it possible to pick a perfect back height. It also showed us that the kneelers needed to have more than 90 degrees of motion. A slight alteration of the pin placement opened the range of motion to around 110 degrees.
There were many other details that needed resolving during this portion of the design phase but they were much simpler and were easily figured out.