Design QA/QC best practices
A structured approach to quality assurance and quality control for design drawings.
QA vs. QC
QA (quality assurance) and QC (quality control) are not the same. QA is about the process, standards, templates, review procedures, training, software, that produces consistent quality. QC is the actual checking of deliverables before they leave the office. Both are required. Strong QA reduces the QC burden, but never eliminates it. For the foundational definitions and examples, see QA vs QC in construction.
QA: process controls
- Office CAD/BIM standards and templates that match the firm’s output
- Standard details library, reviewed and maintained
- Specification master kept current with code and product updates
- Project setup checklist for new project files
- Discipline coordination workflow defined and followed
- BIM execution plan tailored to project complexity
- Document control system with revision tracking
- Issue/release procedure with explicit sign-offs
- Continuing education and code update training
QC: review milestones
- Internal SD / DD / CD reviews led by a senior reviewer not on the project team
- Coordination reviews where each discipline checks against the federated model
- Constructability review at 90% CD
- Code compliance review at every milestone
- Specification cross-reference check at every issue
- Final issue check immediately before drawings leave the office
Reviewer roles
- Independent Senior Reviewer, Not part of the production team, reviews for technical correctness and firm standards
- Code Reviewer, Reviews for code compliance specifically, ideally a licensed professional with code consulting experience
- Constructability Reviewer, Typically a contractor or estimator, reviews for buildability and biddability
- Specification Reviewer, Cross-checks specs against drawings for consistency
- Discipline Lead, Reviews within their discipline for completeness and coordination
Structured checklists beat memory
Reviewers who work from a written checklist catch more issues than reviewers who rely on memory. Checklists should be:
- Discipline-specific
- Project-type-specific (healthcare vs. office vs. industrial)
- Code-edition-specific
- Updated after every project with new lessons learned
- Filled out and signed, not just consulted
The single biggest QC failure is reviewing your own work. Build a peer review culture where no package leaves the office without a second pair of eyes from outside the project team.
Common document errors a good QC catches
- Sheet index references to sheets that don’t exist or are misnumbered
- Detail callouts pointing to non-existent details
- Door schedule mismatches between architectural and door schedule
- Wall types on plans not listed in wall type schedule
- Elevations and sections not aligned with current plans
- Specifications referencing deleted drawings or sections
- Inconsistent terminology (e.g., “owner” vs. “tenant”) across docs
- Cover sheet code summary not matching current edition
- North arrows inconsistent between disciplines
Closing the loop
QC isn't complete when issues are found, it's complete when issues are resolved and re-checked. Maintain a QC log that tracks each issue, the responsible party, the resolution date, and the re-check confirmation. Trend the log over time to identify systemic problems that should be fixed in QA process, not just QC review.
Keep exploring
Related references on coordination, claims, and drawing QA.
How to keep every discipline aligned through design.
How design defects drive change orders and disputes.
The link between document quality and construction claims.
A structured checklist for completeness before issue.