You can deviate from the specs if:

The appropriate situation for deviating from the specifications is when the client approves the change in writing. This is important because written approval provides a clear, formal record of the client's consent to changes, preventing misunderstandings or disputes later on regarding project deliverables or quality standards. Adhering to this requirement safeguards the interests of both the client and the contractor by ensuring that all parties are on the same page regarding modifications to the original specifications.

Involving the general contractor's verbal acceptance, documenting changes by the project manager, or relying on revised plans issued by the architect can create ambiguity. Verbal agreements lack the formal documentation needed for project accountability, while changes documented by a project manager may not have the necessary client acknowledgment. Moreover, architect-issued revisions would typically not suffice without client approval as well. Each of these scenarios could lead to complications, making written consent from the client the most reliable means of authorizing deviations.