Who is authorized to make a material substitution on a blueprint?

The correct answer is that the architect, or a person who has the authority of an architect, is typically the one authorized to make a material substitution on a blueprint. This authority comes from the architect's responsibility for the overall design and integrity of the project, ensuring that any substitutions align with the project's specifications and intent.

In practice, when it comes to design and construction documents, the architect plays a key role in interpreting the intent behind the materials specified. Substituting materials can significantly impact aesthetics, performance, and compliance with building codes, which is why the authority to make such changes is generally granted to the architect or their qualified representatives.

Understanding the roles of other professionals, such as engineers or contractors, is also important, but their authority may be limited to specific aspects of the project or based on the contractual relationships established. Typically, a contractor may suggest substitutions for practical reasons like cost or availability, but final approval usually rests with the architect.