What determines the type of materials or methods used?

The type of materials or methods used in construction is primarily determined by specifications. Specifications are detailed descriptions of the work to be completed within a construction project and outline the quality of materials, workmanship, standards, and methods required. They provide guidance to contractors and ensure that the final output meets the expectations set by architects or engineers.

Specifications also serve as a contract document that details the exact requirements for a project, encompassing everything from structural elements to finishes, and dictate how a project is to be built. By providing precise descriptions, they help in ensuring that the contractor uses the proper materials and follows the acceptable methods to achieve compliance with the design intent and performance criteria.

In contrast, building codes provide safety, health, and welfare regulations but do not specifically dictate the materials to be used; they ensure compliance with minimum standards. References can provide additional information but are not definitive default standards in a contract. Underwriters Laboratories (UL) is a specific organization known for testing and certifying products, which can inform specifications but does not determine them directly.