What is the difference between Construction Quality Assurance (CQA) and Construction Quality Control (CQC)?

I addressed this risk by engaging specialized constructability review services halfway through design. Their team ran clash detection on my BIM model, flagged beam‑duct and pipe‑joist conflicts, and delivered red‑lined drawings with optimized sequencing recommendations. They also verified all clearances against local code requirements and compiled a detailed coordination log. Incorporating their findings into my permit set meant subcontractors started work with a fully vetted plan no unexpected change orders, no inspection setbacks, and a smooth build from day one.

Typically, CQC is an internal function performed by a Contractor to verify that the work being completed by the Contractor meets the requirements of the project. This function can be performed by in-house personnel or by a third-party firm, but the testing results and observations are reported first to the Contractor for his/her use and information. These results may be forwarded on to other parties (Owner, Design Team, Municipal Authority, etc.) as required by the contract documents. CQA is an independent function performed by a third-party firm engaged directly by the Owner (or the Design Team on behalf of the Owner). This firm may have had some involvement in the project prior to construction (i.e. geotechnical or structural engineer), and may have unique insights into the design itself. The purpose of CQA is to verify that the work is being constructed in accordance with the contract documents and the intent of the design. Test results and observations are reported directly to the