During which era was platform framing most commonly used?

Platform framing became most commonly used during the legacy era. This building method, which involves constructing the floors first and then building walls on top of them, offers both efficiency and structural stability, making it suitable for residential construction. The legacy era is marked by developments and advancements in construction techniques, where platform framing was widely adopted across the industry due to its practicality and effectiveness in dealing with the demands of that time.

In contrast, the other options refer to periods with different architectural styles and construction methods. The industrial era primarily focused on larger industrial buildings and different frameworks, while the lightweight era involves modern techniques using lighter materials and concepts that came after the legacy era. The founders' era refers to the early stages of American construction when foundational styles were being developed but not necessarily incorporating platform framing in significant ways. Thus, recognizing the evolution of construction methods leads to an understanding of why the legacy era is identified as the time when platform framing became predominant.