Quality Control Versus Quality Assurance in Construction Projects: How Are They Different?

Quality Control Versus Quality Assurance in Construction Projects: How Are They Different?

Within construction, quality management is the system used to assure user safety. It assures that buildings are built to code and that users will be safe inside them. Quality assurance and quality control together build quality systems management. Quality systems management helps inspection processes move smoothly. Without proper quality systems management, a project might not be built to code requiring a lot of time and money in rework. These two distinct processes are important in building effective and beneficial quality systems.

quality control versus quality assurance
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Quality Control (QC) Versus Quality Assurance in Construction (QA)

Quality control and quality assurance are used interchangeably; however, in construction, they’re two separate parts of quality system management. Without one or the other, the quality system won’t be as effective.

Quality assurance is the planning and systemic activities implemented in a quality system to fill quality requirements. So quality assurance is looking at the quality requirements and making a plan to meet requirements. Quality control is the hands-on part of quality assurance. It is the observation of techniques and activities used to fulfill the requirements and plans set forth by quality assurance. While quality control is often a part of operations, QC isn’t an effective quality management system.


Pre-design work is where quality assurance will take precedent. Looking at the project scope and needs, a quality assurance manager will research all requirements for the building. They will determine what each team needs to complete to pass inspection. They will also determine the requirements for supplies necessary to pass inspection, as well. The quality assurance manager will then arrange all documentation and explain any confusing standards. This way all teams and quality control officers know what to look for and how to meet or surpass standards.

quality control versus quality assurance
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Pre-Construction Design

In the design and planning phase quality control takes over. They are the ones inspecting and testing whether or not the project will meet the standards set by the quality assurance manager. Quality control will ensure the design standards for engineers, architects, building codes and such. The quality control officer is also responsible for signing off on all designs, revisions, and materials proposed. If they sign off on parts that don’t meet the necessary standards, the quality control officer is accountable and not the quality assurance manager.


While the quality assurance manager sets supply and material standards, the quality control officer is responsible for approving them. If a supplier delivers substandard material, it is the job of the quality control officer to fix it. However, the quality assurance manager sets the procedure for fixing supply or material issues. Depending on the contracts and procedures the quality control officer will follow through on assuring material quality requirements which can hold up construction. However, it also prevents additional rework from substandard materials. If materials meet or exceed standards, then the quality control officer can sign off on the materials and construction can begin.

Construction: During the Build

During the construction phase, the superintendent is responsible for assuring the work is up to standards. The quality assurance manager will supply the superintendent with the right documentation and knowledge. Since quality control officers or inspectors visit and test on set schedules, the superintendent is in charge of assuring quality work. If the superintendent notices a problem, it is their job to follow quality assurance protocols and correct it. Introducing more training or refresher courses can improve work quality. This way the quality control officer will be able to approve work on the project. Thereby reducing the amount of rework necessary and keeping the project on time and budget.


When construction wraps up, it is the quality control officer’s job to finish the building inspection. The building inspection will list any parts that aren’t up to code as well as parts that are up to code. This is where the final steps of the quality assurance procedures wrap up. The quality assurance manager will have procedures in place for every part of the project and building in case it doesn’t pass inspection. If the building passes inspection, then the quality assurance officer and quality control officer are done with this project and can work on the next project.

While quality control and quality assurance are different, they’re part of the same system. Without one or the other building rework and building quality will suffer. Quality systems management isn’t quality control versus quality assurance; it’s about both parts working together to assure safe buildings.