Aluminum branch wiring was used as a substitute for expensive copper wire approximately when?

Aluminum branch wiring began to be used widely as a cost-effective alternative to copper in residential applications during the period from 1963 to 1974. This shift was largely driven by the rising costs of copper, prompting builders and electricians to seek less expensive materials that could still meet electrical needs.

During this time, aluminum became a popular choice due to its lower material cost and lighter weight. However, it’s important to note that aluminum wiring can present certain safety concerns, such as increased risk of overheating and connections that are not electrically reliable if not properly installed. This period was crucial in shaping regulations and building practices around electrical wiring, leading to increased scrutiny and improvements in installation techniques in the years that followed.

The other timeframes listed do not correspond to the significant use and recognition of aluminum branch wiring in residential applications, making the choice of 1963 to 1974 the correct and relevant context for this question.