外枠

1. Origins, structure, and basic meaning

• Structure: 外枠 (そとわく) is a noun for an object's outer frame or, figuratively, the overall framework of a plan.
• Basic usage: It applies both to a physical perimeter such as a window frame and to an outline established before details.
  • 窓の外枠を白い塗料で塗り直した。 — We repainted the window's outer frame white.
  • 計画の外枠を決めてから細部を詰めた。 — After setting the overall framework, we refined the details.

2. Common pitfalls and similar expressions

• Physical and figurative frame
  • 枠 broadly means a frame or limit, while 外枠 emphasizes the outermost structure. In planning, it contrasts the overall outline with 細部, details.