Final answer:
Alternate materials or methods in construction must be approved by the local building authority to be used, and this approval is contingent on the alternatives meeting safety and performance standards.
Step-by-step explanation:
The provisions of the building code often include the possibility of using an alternate material or method of construction as long as it is approved by the local building authority. Approval is typically granted if the alternative is proven to be safe, meets or exceeds the performance standards of the prescribed method or materials, and is in compliance with the relevant building codes. The cost, durability, and safety are all factors that the local building authority may consider, but the key requirement is approval, regardless of whether the alternative is cheaper, more durable, or safer than the original.