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About the Interior Design Fundamentals (IDFX) Exam Division of NCIDQ

April 5, 2021
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Making the decision to become a certified interior design professional by the National Council for Interior Design Qualification (NCIDQ) is a big step. Learn about the first section of the NCIDQ, the IDFX (Interior Design Fundamentals) exam.

IDFX Exam Format and Length

The Interior Design Fundamentals Exam division of the NCIDQ Exam is three hours long with 125 questions.

One hundred of these interior design topic questions are scored, and the remaining 25 are used for developmental purposes and not scored.

IDFX Exam Test Taking Tips

We recommend reviewing our interior design study books, as well as using the following tips for taking the NCIDQ IDFX exam:

  • Aim to finish each question in no more than 1 minute 15 seconds. This will leave a reserve of about 20 minutes to guess unanswered questions at the end of the exam session.
  • Eliminate obviously incorrect options before you attempt to guess, because the chances of guessing correctly are better between two choices than among four.
  • Look for an exception to a rule or a special circumstance that makes the obvious, easy response incorrect. Although there may be a few easy and obvious questions, it’s more likely that a simple question has a level of complexity that is not immediately obvious.
  • Take note of absolute words such as “always,” “never,” or “completely.” These words usually indicate some minor exception that can turn what reads like a true statement into a false statement, or vice versa.
  • Watch for words like “seldom,” “usually,” “best,” or “most reasonable.” These words often indicate judgment will be involved in answering the question, so look for two or more options that may be similar.
  • If a question appears to be fundamentally flawed, make the best choice possible under the circumstances. Flawed questions do not appear often on the exam, but when they do, they are usually discovered by the council in the grading process. These questions will not negatively impact your score.

IDFX Exam Content Areas

Programming and Site Analysis (15 questions, 15%)
For example:

  • Research methods (interviewing, surveying, case studies, benchmarking/precedent)
  • Analysis tools (e.g., spreadsheets, site photographs, matrices, bubble diagrams)
  • Project context (e.g., space use, culture, client preference)
  • Site context (e.g., location, views, solar orientation)
  • Existing conditions
  • Sustainable attributes (e.g., indoor air quality, energy conservation, renewable resources)
Human Behavior and the Designed Environment (10 questions, 10%)
For example:

  • Influences (environmental, social, psychological, cultural, aesthetic, global)
  • Human factors (e.g., ergonomics, anthropometrics, proxemics)
  • Sensory considerations (e.g., acoustics, lighting, visual stimuli, color theory, scent, tactile)
  • Universal Design
  • Special population considerations (e.g., Aging in Place, pediatric, special needs)
Building Systems and Construction (15 questions, 15%)
For example:

  • Building construction types (e.g., wood, steel, concrete)
  • Building components (e.g., doors, windows, studs)
  • Mechanical systems
  • Electrical systems
  • Lighting systems (e.g., zoning, sensors, daylighting)
  • Plumbing systems
  • Structural systems
  • Fire protection systems
  • Low voltage systems (e.g., data and communication, security, A/V)
  • Acoustical systems
Furniture, Finishes, Equipment and Lighting (15 questions, 15%)
For example:

  • Life safety (e.g., flammability, toxicity, slip resistance)
  • Textiles
  • Acoustics
  • Wall treatments
  • Floor coverings
  • Ceiling treatments
  • Window treatments
  • Lighting (e.g., flight sources, fixtures, calculations, distribution color rendering)
  • Furniture and equipment (e.g., types, uses, space needs)
Construction Drawings and Specifications (20 questions, 20%)
For example:

  • Demolition plan
  • Floor plan (e.g., partitions, construction, dimensions, enlarged)
  • Reflected ceiling plan
  • Lighting plan
  • Power and communication plan
  • Furniture plan
  • Finish plan
  • Elevations, sections, and details (e.g., partition types, millwork)
  • Schedules
  • Specifications (e.g., prescriptive, performance, and proprietary)
Technical Drawing Conventions (15 questions, 15%)
For example:

  • Measuring conventions (e.g., scale, unit of measure, dimensioning)
  • Construction drawing standards (e.g., line weights, hatching, symbols)
Design Communication (10 questions, 10%)
For example:

  • Functional parti diagrams
  • Models (e.g., physical, virtual)
  • Rendering (e.g., 2-D, perspective)
  • Material and finish presentations (e.g., boards, binders, digital)
  • Bubble diagrams
  • Adjacency matrices
  • Charts (e.g., flow chart, Gantt chart)
  • Stacking/zoning diagrams
  • Block plans/square footage allocations
  • Floor plans
  • Mock-ups and prototypes

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