Who has liability for a proprietary specification if an approved substitution fails?

The contractor holds liability for a proprietary specification if an approved substitution fails primarily because they are responsible for the implementation of the specifications and the overall execution of the construction project. When a contractor submits a request for a substitution and that substitution is approved, they assume the risk associated with its performance. This includes ensuring that the substituted product meets the performance and quality standards outlined in the original proprietary specification.

In the context of construction contracts, the contractor is accountable for the materials and methods they choose to employ, even if those materials were initially recommended or approved by the architect or engineer. While the architect or engineer plays a crucial role in design and may provide guidance on materials, once an approved substitution is made, the contractor is tasked with ensuring that it performs adequately within the parameters set by the project specifications. This allocation of risk encourages contractors to thoroughly evaluate and verify the suitability of substituted materials before proceeding with their use.