适当性证书 Certificate of Appropriateness

关键定义 KEY DEFINITION

Certificate of Appropriateness（COA，适宜性证书）是 Historic District 中 Property Owner 进行 exterior alteration 前须从 preservation board 获得的 approval，确保 changes 符合 historic character。Unauthorized work 可能 require reversal 并 fine—— renovation budget 和 timeline 须 include COA process。