NCIDQ common mistakes
NCIDQ · Understand the traps and how to avoid them.
Calculating occupant load from the overall floor area when the adopted code requires a net-area factor for the specific use, or applying the wrong occupancy classification before sizing egress.
Candidates memorize a few occupant-load factors and default to gross area because it is faster, especially when the plan does not clearly label every room's use.
What to do instead
Classify each space by occupancy/use first, select the adopted code's net or gross factor for that use, calculate occupant load room by room, and then verify egress width, exits, and travel distance against the resulting numbers.
Sizing plumbing fixtures from the total occupant load without separating by sex or checking the adopted plumbing code's fixture ratios and accessible-fixture requirements.
Fixture counts are often treated as a simple ratio problem, and candidates overlook that the plumbing code uses different ratios by occupancy and sex and adds accessibility requirements.
What to do instead
Determine occupant load by use and by sex as required, apply the adopted plumbing code table, add the required accessible fixture, and document the calculation on the fixture schedule.
Writing a specification that names a product as 'or equal' without establishing a named basis-of-design product with salient performance characteristics and a substitution procedure.
Candidates use 'or equal' as a shortcut to avoid committing to a product, not realizing it creates ambiguity and weakens the specification.
What to do instead
Name a basis-of-design manufacturer and model, list the salient characteristics that make it acceptable, and include the project's substitution procedures and deadlines.
Issuing a drawing set in which dimensions, schedules, RCPs, and elevations disagree because each sheet was checked in isolation rather than as a coordinated set.
Parallel drafting and last-minute revisions create local corrections that are not propagated to every affected sheet, schedule, and detail.
What to do instead
Run a cross-sheet coordination check: overlay plans and RCPs, reconcile room names/numbers and dimensions, compare schedules to plans, and verify revision clouds and triangles match across all sheets.
Stamping a contractor's submittal as 'approved' when the contract only authorizes the design professional to review for conformance with the design concept and contract documents.
Candidates confuse submittal review with acceptance or approval, and they may use everyday language instead of the contract's defined review actions.
What to do instead
Use the contract's specific review action terms, such as reviewed with no exceptions noted, reviewed with corrections noted, rejected, or submit specified item; avoid 'approved' unless the contract expressly authorizes it.
Designing directly from the client's room list without validating areas, adjacencies, circulation, and operational requirements.
A written room list feels authoritative, so candidates treat it as a final program instead of testing it against actual use and building constraints.
What to do instead
Interview and observe users, build an adjacency matrix, test net and gross area assumptions and circulation, and issue a written program for client confirmation before planning.
Applying accessibility requirements from memory or from a single source without confirming the governing local code and the stricter applicable requirement.
Candidates may know general ADA concepts but not check whether a state or local code imposes additional or different requirements, especially for toilet rooms, routes, and reach ranges.
What to do instead
Identify the governing authority having jurisdiction, compare local accessibility code with federal requirements, apply the stricter requirement, and verify accessible routes, clear floor spaces, reach ranges, and toilet-room layouts on the drawings.
Selecting ceiling heights and finish locations without coordinating the ceiling plenum with ductwork, sprinklers, lighting, structure, and acoustic requirements.
Interior finish and reflected-ceiling plans are often developed before or separately from mechanical, electrical, and structural coordination, so conflicts are discovered late.
What to do instead
Coordinate the RCP with structural depth, duct and diffuser locations, sprinkler heads, light fixtures, and acoustic performance; confirm plenum clearance and revise ceiling heights or specifications before issuing.
Specifying a finish from appearance samples alone without checking durability, maintenance, fire/smoke rating, slip resistance, or manufacturer test data for the actual application.
Visual selection is immediate and persuasive, while performance data and maintenance implications require extra research that candidates skip under time pressure.
What to do instead
Establish performance criteria for the application, compare manufacturer data and test standards, verify fire and smoke ratings where required, and confirm maintenance and cleaning requirements with the owner.
Allowing a client's verbal request for additional work to proceed without a written change order, additional services agreement, or other contract authorization.
Candidates want to be responsive and may treat a small request as part of the original scope, overlooking contract scope and compensation requirements.
What to do instead
Compare the request to the contracted scope, document it in writing, issue or request a change order or additional-services authorization before performing the work, and record the decision in the project file.