Which of the following requires a permit during installation?

Installing a new air conditioning condensing unit typically requires a permit because it involves mechanical systems that can impact energy efficiency, safety, and local building codes. The installation must comply with standards that ensure proper operation and safety, such as electrical connections, drainage, and structural considerations. Obtaining a permit allows the local authority to review the plans and ensure that the installation meets all applicable regulations.

In contrast, replacing windows may or may not require a permit, depending on local regulations and the extent of the work. Painting the exterior and landscaping changes are generally cosmetic adjustments that do not affect the structural integrity or the mechanical systems of a building, thus usually do not require permits. These activities often fall under minor improvements that local governments do not regulate as strictly as mechanical installations.