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On-Line Class
24/7 anywhere access - Live (via Zoom) & On-line Class


The California Legislative Coalition for Interior Design (CLCID) sponsors The Original IDEX CA Prep Class©.  This class is designed to prepare you to sit for the IDEX California®.   The IDEX California® is the only California approved exam for Interior Design certification.

The Original IDEX CA Prep Class© is the only IDEX California® prep class that gives back to the profession through the efforts of a dedicated group of CLCID volunteers who represent the entire profession on issues critical to interior designers and their practice.

Quiz questions throughout the class will reinforce the learning process.  These questions are designed in the format of the IDEX California® questions but are not the exact questions on the IDEX California®.   However, these questions are similar to those on the exam.  There is also a Quiz Shuffle Review at the conclusion of the class.  The Original IDEX CA Prep Class© is inclusive of all of the IDEX California® content.

A link to printable handouts for more difficult lessons is located at the bottom of the corresponding lesson.

To start a lesson, click the lesson title

(You must complete each quiz question correctly before proceeding to the next lesson.)


Lesson 02 – Human Dimensions and Closure

The purpose of the California Building Code is to ensure that barrier-free design is incorporated in all buildings, facilities, site work and other developments to which this code applies and to ensure that they are accessible to and usable by persons with disabilities.  The American with Disabilities Act (ADA) is a civil rights act, separate […]

Lesson 03 – Limitations

Interior designers are never permitted to do structural or seismic work.  This work is the responsibility of structural engineers and/or other qualified professionals. Structural engineers in particular, design structures to withstand stresses and pressures, such as weather and human use.  They ensure buildings and other structures do not bend, twist, collapse or vibrate and remain strong and secure throughout their use. […]

Lesson 04 – Code Enforcement

Who monitors the building code compliance for safety? Building departments in every city and/or county are fully empowered.  The local building official is responsible for making sure the building is compliant with the current California Building Code. The California Building Standards Commission (CBSC) is responsible for administering California’s building codes, including adopting, approving, publishing, and implementing […]

Lesson 05 – Certificate of Occupancy

Building permits are issued on the front end of the project and a Certificate of Occupancy is issued on the back end.  The buildings or structures are issued a Certificate of Occupancy because they are complete and in compliance with the laws and regulations for which the occupancy has been applied.  No building shall be used or occupied […]

Lesson 06 – Appeal Boards

So what if you do not like a building official’s code interpretation? Every city and/or county is directed to establish a local Board of Appeals.  The local Board of Appeals hears appeals related to the building official’s code interpretations.  The Board can review a decision or order of the local building official.  These appeals could include […]

Lesson 07 – Use and Occupancy Classifications

Occupancy Groups The key to using the California Building Code (CBC) are the Occupancy Groups.  There are 12 Occupancy Groups.  You must learn these groups to navigate the codes and to classify construction documents.  You must also know these groups and their abbreviations in order to read and interpret the tables in the CBC and on the IDEX […]

Lesson 08 – Means of Egress for Occupancy Loads

Occupancy Loads Occupancy loads covers fixed seating, outdoor areas and exiting. Occupant load for fixed seating shall not be less than the number of seats based on one person for each 18 inches of seating width (pictured) and the occupant load shall not be less than 24 inches of booth seat width per person. The […]

Lesson 09 – Types of Construction

Types of Construction Types of construction govern the type of allowable building materials for fire resistance.  All construction types have A and B subdivisions based upon the building height and occupancy except for TYPE IV. TYPES I and II are the most restrictive for all construction materials on the exterior and interior of the building.  All […]

Lesson 10 – Structural and Fire Retardance

Ceiling and Wall Surfaces According to the Gypsum Association, 80% of interior ceiling and wall surfaces are covered with gypsum board, AKA wallboard, drywall or sheetrock.  These are the classifications for the most common types of gypsum board: Regular gypsum board has a pale gray paper face and comes in a variety of thickness with ½ […]

Lesson 11 – Fire Code Door Assemblies and Walls

Fire Doors, Walls and Blocking The fire door assembly consists of any combination of a fire door, frame, hardware and other accessories that together provide a specific degree of fire protection to the opening. Fire doors shall have approved and permanently affixed labels.  Panic door hardware is required for Group A Occupancies for 50 or more occupants.  More […]

Lesson 12 – Fire Code Systems

Fire Protection Systems and Alarms California fire codes are the information source for fire alarm and detection systems.  The fire code official shall approve any fire extinguishing systems installed as an alternative to the required automatic sprinkler systems. Fire alarm boxes are RED.  Manual fire alarm boxes are not required if the building has a […]

Lesson 13 – Routes and Exits

Commercial Corridors as Means of Egress The means of Egress is a continuous and unobstructed path of vertical and horizontal egress travel from any occupied portion of a building to a public way.  A public way is a street, alley or other parcel of land open to the outside air leading to a public street. […]

Lesson 14 – Exit Doorways

 Accessible Means of Egress Accessible means of egress is a continuous and unobstructed way of egress travel from any accessible point in a building to a public way. Means of egress with one exit door shall have an exit that is obvious.  The path of egress travel shall be 75’ or under. Table 1015.1 shows […]

Lesson 15 – Doors and Hardware

Doors have fire ratings for commercial installations.  Fire door assemblies include the entire door frame.  Fire doors shall have approved and permanently affixed labels. Fire doors are required to have a minimum fire protection rating of 20 minutes when located in corridor walls for all occupancies.  Door assemblies in corridors and smoke barriers shall meet […]

Lesson 16 – Stairways

Stairway Dimensions:            Width: 44 inches/48 inches Minimum headroom: 80 inches Minimum risers: 4 inches Maximum riser: 7 inches Minimum tread with no nose extension: 11 inches Minimum nose: 1-1/4 inch maximum extension The stairways shall have a minimum width of 44 inches minimum. Exceptions include a 36 inches minimum for occupant loads of less […]

Lesson 17 – Handrails

Handrails or Handgrips Handrails with a circular cross-section shall have an outside diameter of at least 1-1/4 inches to a maximum of 2-1/4 inches.   The perimeter shall be 4 inches to 6-1/4 inches.  The handgrip portion of handrails shall have a minimum radius of 1/8 inch to ease the corners.  The surface shall be smooth […]

Lesson 18 – Ramps

Ramp Criteria The maximum ramp slope of 1:12 has the following requirements: The maximum rise between landings is 30 inches The length of incline is 30 feet Handrails are required The maximum ramp slope 1:20 has the following requirements: The maximum rise between landings is 30 inches The length of incline is 40 feet Handrails […]

Lesson 19 – Elevators, Ceilings and Hazards

Elevators for Multifamily Buildings Passenger elevators for multifamily buildings shall be located on a major accessible route. A door reopening device shall also be capable of sensing an object or person within 5 inches at 29 inches AFF in the path of closing without requiring contact.  Elevator doors must remain fully open in response to a […]

Lesson 20 – Reach Accessibility

Accessible Side Reach The following minimum dimensions are where clear floor space allows a direct parallel approach to an element. The unobstructed side reach shall have a maximum high of 48 inches AFF and a minimum low of  15 inches AFF. The maximum high side reach over a 10-inch deep obstruction shall also be 48 inches maximum […]

Lesson 21 – Natural Light and Glazing

Length: 0 minutes

Light and Ventilation Light is part of the electromagnetic spectrum and is termed as sine waves.  Sine waves can be reflected, transmitted and absorbed. The minimum net glazed area for natural light shall not be less than 8% of the floor area of the room served.  This includes all exterior windows and skylights. The minimum openable area to […]

Lesson 22 – Artificial Lighting

Electrical Light sources can serve three functions to meet human needs: Ambient lighting is background or fill light that spreads an even, overall luminosity and reduces harsh contrasts between pools of concentrated light. Task lighting is functional and localized light for a particular activity such as office work, reading, writing, preparing food or grooming.  The […]

Lesson 23 – Flooring

Carpet and Doormats Carpet shall have a level loop, textured loop, level-cut pile or level-cut/uncut pile texture.  The maximum pile height shall be ½”.  Exposed edges of carpet shall be securely fastened to floor surfaces. Select carpets that are colorfast, resistance to fading by exposure of light and resistance to crocking (color rubbing off). Carpet […]

Lesson 24 – Interior Space Dimensions

Interior Space Dimensions Occupiable spaces (working) such as in commercial buildings and habitable spaces (living) such as bedrooms, living rooms, family rooms, offices, etc., shall have a ceiling height of 7 feet-6 inches or 90 inches.  Habitable space exceptions are bathrooms, kitchens, storage rooms and laundry rooms.  These shall be permitted to have a ceiling height […]

Lesson 25 – Sound and Acoustical Ratings

Sound and Acoustical Rating Noise travels in two ways.  Airborne sound insulation is the acoustically rated separation of the wall and floor-ceiling assemblies.  Impact sound insulation is echoed from surface contact such as walking on a floor. Sound Transmission Class (STC) measures noise levels.  STC is a single number rating used to compare the effectiveness of […]

Lesson 26 – Toilet Room Accessories and Fixtures

Accessible Water Closet (WC) Back Wall Blocking The drawing above shows an example of 40-inch blocking in the back wall to install a 36-inch grab bar.  The grab bar shall support a 250-pound point load.  Accessible Water Closet (WC) Grab Bars The rear grab bar shall be a minimum of 36 inches long and extend […]

Lesson 27 – Toilet Room Clearances

Accessible Single Accommodation The minimum clear space required for the water closet (WC) from the wall to the adjacent side edge of the lav or the adjacent side wall shall be 60 inches to allow for a side transfer from a wheelchair.  There shall also be a 60 inch diameter clear floor space for the […]

Lesson 28 – Fireplaces

Fireplace Clearance to Combustibles A minimum distance is required between an exposed combustible edge of sheathing material such as wood siding and the firebox in a masonry fireplace.  A combustible material framing a firebox must clear by 6 inches on all sides and can be up to 1-1/2 inches from the face of the masonry.  A […]

Lesson 29 – Interior Surfaces and Finishes

Interior Finishes This part of the code governs the use of materials used in interior finishes, trim and/or decorative materials based upon the location and the Occupancy Group. The third party test main objectives need to be memorized for identification in multiple choice questions. CBC Part 2, Volume I, Table 803.5 is the reference used […]

Lesson 30 – Establishing a Business

Legal protection of personal assets starts with types of legal formations that protect personal assets.  Choices could include corporations or LLCs. Business consultants are critical in starting a business.  Of all the business consultants, your attorney is the most crucial.  Your attorney should review your legal business formation and your design firm’s contract or letter […]

Lesson 31 – Contracts and Letters of Agreement

Design Contracts Contracts and Letters of Agreement are very important, especially if you want to be paid.   A Letter of Agreement is a less formal contract.  It affords a designer the same legal consideration for enforcement and like a contract, it should also be reviewed by legal counsel.  Services, compensations/payments, responsibilities and date/signature of parties are the same in both […]

Lesson 32 – Estimating Costs and Design Fee Methods

Quoting Investment projections include: Quality ranges Typical arrangements Square-foot factor Standard materials and labor Budget is a limiting word.  Use the word investment with your client as the returns for the investment are in the enjoyment of the space and resale.   It is important to respect the client’s investment dollars. Specifying a project that comes […]

Lesson 33 – Sales Tax

State and Local Sales Taxes Every interior designer or decorator should have the booklet on tax tips “State Board of Equalization Bulletin for Interior Designers and Decorators”.  This booklet is available from the state or on-line – www.boe.ca.gov/pdf/pub35.pdf. Resale licenses stipulate that the interior designer is exempt from paying sales tax at the time of ordering […]

Lesson 34 – Liabilities and Insurance

Liabilities Liabilities always have first claim on the firms’ assets.  All liabilities shall be paid before owners or stockholders receive any funds. Current liabilities are obligations that are due within one year or less.  Included are accounts payable, claims from suppliers for goods and services ordered and possibly delivered, short term loans such as lines […]

Lesson 35 – Programming

Complete Scope of Services Design phases drive the design process from the beginning to completion of the project.  They provide the scope of services in a design contract.  The design phases consist of: Programming Schematic Design (AKA Concept Design Phase) Design Development Contract Documents Contract Administration  Phase 1 – Programming This is the information gathering […]

Lesson 36 – Sustainability

Sustainable Design Environmental consideration is part of the evolution of the FF&E specifications.  LEED stands for Leadership in Energy and Environmental Design from the USGBC – U.S.Green Building Council (www.usgbc.org/leed).  The practice focuses on the use of products and methodologies to lessen the impact on the natural environment and improve the interior environment (green).  The program establishes standards for […]

Lesson 37 – Schematic Design

Phase 2 – Schematic Design (AKA Concept Design) Written concepts Adjacency matrix Bubble diagrams Block plans Preliminary floor plans Preliminary F,F&E schedules Design sketches This phase consists of the preliminary formulation of the character, function and aesthetics of a project.  Generating these ideas for drawings is also known as the Concept Design phase.  This Schematic Design phase provides the […]

Lesson 38 – Design Development

 Phase 3 – Design Development F,F&E specifications Final space plan Final furniture plan Working drawings Presentation graphics Project budget It is very important for the designer in the Design Development phase to conduct final consultations with technical consultants to review any changes, especially specifications of FF&E and finishes, for the client’s final review. The Design Development phase also […]

Lesson 39 – Contract Documents

Phase 4 – Contract Documents Phase 4 embodies Contract Documents and is sometimes called the CD or the Document Phase.  This phase consists of all of the documents needed to build, bid or purchase materials to complete the project.  These are considered a legal document constituting a contract. Complete Contract Documents are primarily construction documents including all working and technical/shop drawings that […]

Lesson 40 – Contract Administration

Phase 5 – Contract Administration At this point the designer must have the approval of all technical/shop drawings and have completed the submittal review. Contract Administration involves the results of the competitive bid process and the placing of orders for all furniture and equipment.  This Includes the review and approval of shop drawings and submittals from […]

Lesson 41 – Building Permits and Post Occupancy

Building Permits A building permit is required to build, construct, remodel, repair, demolish, remove or move any building or structure including garages, patios, fences, accessory buildings, car ports, etc.  Examples of special permits that may be required include combined building-mechanical permits, electrical permits such as adding a new bathroom lighting fixture, elevator permits, fire sprinkler […]

Lesson 42 – Contractor License Law

Registered Design Professional This title is defined as “An individual who is registered or licensed to practice their respective design profession as defined by the statutory requirements of the professional registration laws of the state or jurisdiction in which the project is to be constructed.”  The courts in California have upheld that a certification for a […]

Lesson 43 – Notices, Liens and Health Standards

Notice of Completion The Notice of Completion  is primarily designed to protect the owner but it also serves to show completion of the contractor’s work for payment or for filing a Mechanics Lien.  This notice permits lien rights to the interior designer.  It requires the signature of the owner or the owner’s agent.  No additional […]

Lesson 44 – Business Ethics and Legal Notices

Ethics The definition of ethics in the business context is: “A consensus of what constitutes right or wrong behavior in the world of business and the application of moral principles to situations that arise in a business setting.”   Jentz Mille Ethics defines what is right or wrong.  Ethics create operating principles for a firm.  Compromising […]

Lesson 45 – Protection and Responsibilities

Business & Professions Code Section 5801 “A Certified Interior Designer may obtain a stamp that shall include a number that uniquely identifies and bears the name of that Certified Interior Designer.  An original ‘wet signature’ is to be used with the certification stamp on each page of the project drawings to be submitted for pulling […]

Lesson 46 – Elements and Principles of Design

Elements of Design Elements of Design are the most basic visual components of any composition.  The elements are the materials upon which the principles of design act.  Interior designers discover, incorporate, and balance these elements to create a strong solution to a given problem situation. The elements of design may vary by source but often include: Point – something […]

Lesson 47 – Principles of Universal Design

Principles of Universal Design Universal design is the design of products and environments to be usable by all people without adaptions or specialized design.  The seven principles were developed by the Center for Universal Design at North Carolina State University.  Study the order of these principles. Equitable Use:  The design is useful and marketable to […]

Lesson 48 – Basic Types of Design and Color Theory

Basic Types of Design Structural Design results from the size and shape of design of structural materials.  It depends upon simplicity and appropriateness of material used.   Ornamentation or Decorative Design is the ornamentation of basic design structure using color, line, texture and pattern.  The four subcategories are naturalistic, stylized, abstract and geometric design.   Naturalistic […]

Lesson 49 – Textiles, Furniture and Finishes

Textiles Protein fibers include wool and silk. Wool is expensive but has good wearability.  It resists dirt and cleans well.  Advantages include excellent resilience and elasticity and flame retardance as it can absorb 16% to 20% of its weight in moisture without feeling damp.  Disadvantages are that it shrinks, yellows with age and is damaged by […]

Lesson 50 – Cabinetry and Construction Joining Methods

Cabinetry Construction There are three primary construction styles for cabinetry: Framed Frameless or European Tambour These front view drawings demonstrate these three types of cabinets. Framed cabinetry has inset, lipped, overlay and full overlay doors. Frameless cabinetry has full overlay door and concealed hinges.  Sometimes this type of construction is called European. Tambour cabinetry has its own frame. Cabinetry […]

Lesson 51 – Proxemics

Length: 5 minutesComplexity: Easy

Proxemics Proxemics is the study of a use of space by human beings in a particular culture.  It merges cultural, physical and psychological components to create adequate space in interior environment.  Bubbles demonstrate intimate, personal, social and public spaces and are an excellent guideline for the space planning of furniture. Beginnings of Interior Environments; Jones and Allen

Quiz Shuffle Review

The Quiz Shuffle Review is designed to re-enforce your study of the class contents.  This review covers ALL 51 lessons with each quiz question randomized, so you can take it over and over again in a different order.  Note that the reference to the lesson number is at the beginning of each quiz question. If […]

Class Evaluation

The Original IDEX CA® Prep Class Evaluation Please give us your honest opinion of the class. We appreciate your comments as it helps us improve the class for future students.  Once you have completed the evaluation (regardless of your review scores), you will receive your Certificate of Completion for the class by email. After you […]