FE and PE prep courses are starting now! Enroll today to begin on time. Get Started.

NCIDQ Interior Design Reference Manual, 8th Edition

NEW Edition! Presale - Ships December 2026

Available in Print or eTextbook.

Fully updated to the 2026 exam specifications! The Interior Design Reference Manual, 8th Edition by David Kent Ballast offers comprehensive coverage of all three sections of the NCIDQ exams, which include the fundamentals (IDFX), professional (IDPX), and implementation (IDIX) exams. Pass your exams the first time with this new edition, featuring targeted practice questions at the end of every section to lock in the exact concepts you'll face on test day.

NEW features of the 8th edition:

  • Knowledge Checks Included: Practice questions in every chapter to reinforce your learning
  • Study Smarter: Chapters organized by exam for efficient and comprehensive review
  • Aligned to the 2026 Exam Restructure: Tailored precisely to the new three-part division: IDFX (Fundamentals), IDPX (Professional Practice), and the brand-new IDIX (Implementation) format
  • Up-to-Date Code References: Updated for the IBC 2021, IRC 2021, IPC 2021, and ICC A117.1 2017 changes included in the exam

Topics Covered

  • Exam 1: Interior Design Fundamentals Exam
    • Existing Conditions
    • Pre-Design
    • Programming
    • Space Planning
    • Preliminary FF&E and Finishes
    • Schematics
  • Exam 2: Interior Design Professional Exam
    • Feasibility Studies
    • Scheduling and Budgeting
    • Bidding in Contracts, Procurement and Permitting
    • Construction Process
    • Site Observation and Close-Out
  • Exam 3: Interior Design Implementation Exam
    • Codes and Life Safety
    • Integration and FF&E
    • Construction Documents
    • Consultant Drawing Coordination
    • Construction Specifications and Schedules

eTextbook access benefits include:

  • Ability to download the entire eTextbook to multiple devices, so you can study even without internet access
  • An auto sync feature across all your devices for a seamless experience on or offline
  • Unique study tools such as highlighting in six different colors to tailor your study experience
  • Features like read aloud for complete hands-free review
$289.00
PUB YEAR
2026
FORMAT
Paperback or eTextbook
PID# 897145

Exam Details for the NCIDQ Exam

NCIDQ certification is the industry's recognized indicator of proficiency in interior design principles and a designer's commitment to the profession. To earn certification, qualified interior designers can apply to take the NCIDQ Examination. After CIDQ approves their eligibility, candidates register for each of the three sections of the exam and must pass each section within a specified time-frame. The exam is continually updated to ensure it aligns with the most current professional knowledge necessary to design spaces that are innovative, functional, and safe. The three separate sections of the NCIDQ Exam are: the Interior Design Fundamentals Exam (IDFX), the Interior Design Professional Exam (IDPX), and the Interior Design Practicum Exam (PRAC).

Learn More

FAQs

The Council for Interior Design Qualification (CIDQ) administers the NCIDQ Exam. CIDQ, which is composed of regulatory boards from across the United States and Canada, takes seriously its responsibility to protect the public. Accordingly, CIDQ specific education and work experience requirements exist to be eligible to sit for the NCIDQ Examination. You must have official education transcripts and they must include a minimum of 60 semester or 90 quarter credit hours of post-secondary interior design coursework that encompasses a certificate, degree, or diploma from an accredited institution to be eligible. You must also have experience, which consists of up to 1,760 hours of interior design work experience earned prior to graduation. Regardless, CIDQ also warns that meeting CIDQ's education and work experience requirements does not guarantee that a candidate will meet their jurisdiction's requirements to be a licensed interior designer. Individuals are reminded to check with their jurisdiction regarding those specific requirements.
The Interior Design Fundamentals Exam (IDFX), Interior Design Professional Exam (IDPX), and the Interior Design Implementation Exam (IDIX) exams are scored by computer.  Scores are reported on a scale ranging from 200 (0 correct) to 800 (all correct), with the passing point anchored at 500. Results for each exam are processed within 6-8 weeks of the close of the window. Candidates who sat for the exam will receive an email notification once the score has been processed and is available to view in MyNCIDQ. CIDQ takes this time to guarantee that all scores are fair and accurate.

In collaboration with interior designer practitioners, educators, and testing professionals, CIDQ has set a passing point (or cut score) for each NCIDQ Exam. Meeting the passing standard for all three exam sections and achieving NCIDQ certification demonstrates that a candidate is competent to practice in a way that protects the health, safety, and welfare of the public.  The passing point does not change based on your location, the number of candidates taking the exam, or the performance of other candidates taking the exam.

Please look at this infographic by CIDQ for further information 

The Interior Design Fundamentals Exam (IDFX) covers six distinct areas that capture the core competencies of interior design: 

  • Existing Conditions
  • Pre-Design
  • Programming
  • Space Planning
  • Preliminary FF&E and Finishes
  • Schematics

The Interior Design Professional Exam (IDPX) covers five distinct areas that capture the core competencies of interior design: 

  • Feasibility Studies
  • Scheduling and Budgeting
  • Contracts, Procurement, and Permitting
  • Construction Process
  • Site Observation and Close-Out

The Interior Design Implementation Exam (IDIX) covers five distinct areas that capture the core competencies of interior design: 

  • Codes and Life Safety
  • Integration and FF&E
  • Construction Documents
  • Consultant Drawing Coordination
  • Construction Specifications and Schedules
For more detailed information on topics for this divisional exam, please visit the CIDQ website.
The NCIDQ exam is administered by the Council for Interior Design Qualification (CIDQ) - the certifying organization for interior design professionals.

The NCIDQ exam is divided into three sections:

  • Interior Design Fundamentals Exam (IDFX)
  • Interior Design Professional Exam (IDPX)
  • Interior Design Implementation Exam (IDIX)
All are administered by computer and machine graded. All three exams are available to take throughout the entire months of April and October.

For more detailed information on topics for this exam section, please visit the CIDQ website.

NCIDQ Certification is the industry's recognized indicator of proficiency in interior design principles and a designer's commitment to the profession.

To become a certified interior designer in the United States, you’ll need to take the NCIDQ (National Council for Interior Design Qualification) exam. The NCIDQ is administered by the CIDQ, which stands for Council of Interior Design Qualification, and is currently the only nationally-recognized competency exam for interior design. Obtaining your NCIDQ Certification recognizes your proficiency in interior design principles and your commitment to the profession.

The NCIDQ ensures the safety and wellbeing of the public by requiring that design professionals are held to the highest standards in the industry. The content of the exam represents the foundational knowledge you need to be able to branch out into a specialty design area afterwards. The NCIDQ exam consists of three sections: the Fundamentals Exam (IDFX), the Professional Exam (IDPX), and Implementation Exam (IDIX). Each section focuses on public health, safety and welfare.