demolish

Demolish is the act of destroying a building or structure, either completely or to a degree, to clear land for new development or because the structure is unsafe or obsolete. The term derives from the Middle French démolir, from Latin demolire, de- "down" + molere "to crush, grind."

Planning and permits: Demolition projects are planned and executed by licensed contractors under local building codes and safety regulations. Required steps typically include obtaining permits, notifying authorities and neighbors, disconnecting utilities, and conducting surveys for structural stability and underground services. Environmental considerations include the removal of hazardous materials such as asbestos or polychlorinated biphenyls (PCBs) and managing dust, noise, and waste streams.

Methods: Demolition can be performed by mechanical means (using excavators with shears, pulverizers, or wrecking balls), selective or partial demolition, implosion using controlled explosives (usually highly regulated and performed by specialists), or deconstruction, which dismantles a structure to salvage reusable materials. Total demolition destroys the structure entirely, while selective demolition preserves parts for reuse.

Safety and regulation: Demolition carries significant risks to workers and the public. Requirements typically cover site security, personal protective equipment, fall protection, and environmental controls. Regulations vary by country and jurisdiction; in the United States, agencies such as OSHA oversee worker safety, while local building departments issue permits. Best practices emphasize hazard assessment, dust suppression, waste recycling, and responsible disposal.

Impact and alternatives: Demolition can enable redevelopment but raises concerns about urban renewal, historical preservation, and material waste. Alternatives include adaptive reuse and deconstruction to recover building materials for reuse elsewhere.