CASp Domain 2: Prescriptive Requirements of Accessibility Codes and Standards - Complete Study Guide 2027

Domain 2 Overview: Understanding Prescriptive Requirements

Domain 2 of the CASp examination focuses on the prescriptive requirements of accessibility codes and standards, representing one of the most technical and detail-oriented sections of the exam. This domain tests your comprehensive understanding of specific numerical requirements, dimensional criteria, and technical specifications found in accessibility legislation and building codes.

Unlike Domain 1 which covers general knowledge and skills, Domain 2 requires precise recall of specific measurements, percentages, and technical criteria. Beginning with the February 2026 administration, the California Division of the State Architect has updated the examination to test against the 2025 California Building Code, making current knowledge of these prescriptive requirements essential for success.

ADA Accessibility Guidelines Foundation

The Americans with Disabilities Act Accessibility Guidelines (ADAAG) form the federal foundation for accessibility requirements that California has adopted and enhanced. Understanding these baseline requirements is crucial before diving into California's more stringent standards.

Key ADAAG Sections for CASp Candidates

The most frequently tested ADAAG sections include:

• Section 206: Accessible Routes - General exceptions and scoping requirements
• Section 302: Floor and Ground Surfaces - Slip resistance and level changes
• Section 303: Changes in Level - Specific dimensional requirements for level changes
• Section 404: Doors, Doorways, and Gates - Opening force, clear width, and maneuvering clearances
• Section 405: Ramps - Running slope, cross slope, and landing requirements
• Section 504: Stairways - Tread depth, riser height, and handrail specifications

Critical ADAAG Measurements

Element	ADAAG Requirement	Common Test Areas
Door Opening Force	5 lbf maximum	Interior doors, fire doors
Ramp Running Slope	1:12 maximum	New construction, alterations
Ramp Cross Slope	1:48 maximum	Outdoor ramps, walkways
Clear Door Width	32" minimum	Single doors, double doors
Stair Riser Height	4" to 7" uniform	Public stairs, egress stairs

2025 California Building Code Chapter 11A

California Building Code Chapter 11A often exceeds federal ADA requirements, creating a more stringent accessibility standard. As noted in our comprehensive guide to all CASp exam domains, understanding these enhanced California requirements is essential for professional practice in the state.

Chapter 11A Key Sections

The most critical sections of CBC Chapter 11A include:

• 11A-4: Accessible Routes and Entrances
• 11A-5: Parking and Passenger Loading Zones
• 11A-6: Curb Ramps and Ramps
• 11A-7: Stairs and Handrails
• 11A-8: Doors and Doorways
• 11A-9: Windows and Glazed Openings
• 11A-10: Drinking Fountains and Water Coolers

California-Specific Enhancements

California often requires more stringent specifications than federal minimums:

• Parking space dimensions that exceed ADA minimums
• Enhanced signage requirements with specific Braille and tactile criteria
• More restrictive door opening force requirements in certain applications
• Additional accessible route requirements for specific building types

Specific Prescriptive Requirements

This section covers the detailed dimensional and technical requirements that form the core of Domain 2 testing. Many candidates struggle with this material because it requires precise memorization rather than conceptual understanding.

Accessible Route Requirements

Accessible routes must meet specific criteria throughout their entire length:

• Minimum Clear Width: 44 inches for accessible routes, with exceptions for doorways
• Maximum Running Slope: 1:20 (5%) before a route is considered a ramp
• Maximum Cross Slope: 1:48 (2.08%) for outdoor surfaces
• Surface Requirements: Stable, firm, and slip-resistant with specific texture criteria

Parking Requirements

Accessible parking requirements include both scoping (how many spaces) and technical (dimensional) criteria:

Total Spaces	Accessible Required	Van Accessible
1-25	1	1 every 6 accessible
26-50	2	1 every 6 accessible
51-75	3	1 every 6 accessible
76-100	4	1 every 6 accessible
101-150	5	1 every 6 accessible

Ramp Specifications

Ramps represent one of the most technically complex areas of accessibility codes:

• Maximum Running Slope: 1:12 for new construction, 1:8 for existing buildings with space limitations
• Maximum Cross Slope: 1:48 (2.08%)
• Maximum Rise: 30 inches between landings
• Minimum Landing Size: 60" x 60" at changes of direction
• Handrail Requirements: Both sides for rises over 6 inches

Critical Calculations and Measurements

Domain 2 frequently tests your ability to perform accessibility-related calculations. These problems often appear on both parts of the examination and require precise mathematical skills.

Slope Calculations

Understanding slope calculations is fundamental to CASp success. Slopes are expressed as ratios (1:12) or percentages (8.33%), and you must be comfortable converting between formats.

Common Calculation Types

• Ramp Length Determination: Given a rise and maximum slope, calculate required run
• Landing Requirements: Calculate landing sizes based on ramp configurations
• Door Maneuvering Clearances: Apply specific clearance requirements based on door swing and approach direction
• Accessible Parking Scoping: Determine required accessible spaces based on total parking provided

Measurement Tolerances

California accessibility codes include specific tolerances for construction and compliance measurements:

• Construction tolerances typically allow ±1/4 inch for most dimensional requirements
• Slope measurements may have specific tolerance ranges depending on the application
• Some requirements, such as door opening forces, have no tolerance and must meet exact specifications

Common Code Violations and Testing Focus

Understanding frequently occurring violations helps focus your study efforts and provides insight into likely exam questions. As discussed in our analysis of CASp exam difficulty, the examination often focuses on real-world scenarios that CASp professionals encounter regularly.

Most Common Accessibility Violations

• Inadequate Door Maneuvering Clearances: Especially on the pull side of doors
• Excessive Door Opening Forces: Particularly on interior doors and fire doors
• Improper Ramp Slopes: Both running slope and cross slope violations
• Insufficient Accessible Parking: Both scoping and dimensional violations
• Non-compliant Signage: Missing or improperly located accessibility signage

Technical Specification Failures

Many violations stem from misunderstanding specific technical requirements:

• Confusing maximum and minimum requirements
• Applying incorrect tolerances to measurements
• Misunderstanding when exceptions apply
• Incorrectly calculating compound requirements (such as ramp length plus landing requirements)

Study Strategies for Domain 2

Domain 2 requires a different study approach than conceptual domains. Success depends on memorizing specific numbers and understanding their application in various scenarios.

Memorization Techniques

Effective memorization strategies for prescriptive requirements include:

• Flashcard Systems: Create cards for each specific measurement with both the requirement and its application
• Grouped Learning: Study related requirements together (all door requirements, all ramp requirements)
• Visual Associations: Create mental images linking measurements to memorable objects or concepts
• Practice Applications: Work through calculation problems repeatedly until they become automatic

Creating Study Aids

Develop comprehensive study aids that you can review quickly:

• Summary tables of all critical measurements
• Calculation worksheets with common problem types
• Code section quick-reference guides
• Common violation checklists

For additional practice opportunities, consider using the comprehensive practice tests available at our main practice test platform, which includes Domain 2-specific questions that mirror the actual exam format.

Practice Scenarios and Applications

The CASp examination tests prescriptive requirements through realistic scenarios that mirror professional practice. Understanding how to apply technical specifications in context is crucial for exam success.

Typical Exam Scenarios

Common scenario types include:

• Plan Review Problems: Identifying code violations in architectural drawings
• Field Measurement Analysis: Determining compliance based on provided measurements
• Calculation Requirements: Computing required dimensions or quantities
• Code Application Questions: Selecting appropriate requirements for specific building types or conditions

Sample Problem Analysis

Consider this typical exam question: "A ramp serves a 24-inch vertical rise. What is the minimum horizontal run required, and what landing requirements must be met?"

Solution approach:

• Maximum slope is 1:12, so minimum run = 24" × 12 = 288" (24 feet)
• Since rise is less than 30", no intermediate landing is required
• Landing size must be minimum 60" × 60" at top and bottom
• If the ramp changes direction, landing size increases to accommodate turn radius

Exam-Specific Tips for Domain 2

Success on Domain 2 questions requires specific test-taking strategies beyond general exam preparation. Understanding the examination format and question types helps optimize your performance.

Part 1 (Open Book) Strategy

During the open-book portion of the examination:

• Use tabbed references to quickly locate specific code sections
• Verify calculations even when you think you know the answer
• Check for California-specific enhancements that exceed federal minimums
• Consider both prescriptive compliance and equivalent facilitation options

Part 2 (Closed Book) Strategy

The closed-book examination tests your recall of fundamental prescriptive requirements:

• Focus on the most commonly tested measurements during review
• Practice calculation shortcuts and estimation techniques
• Memorize the specific wording of key requirements, as subtle differences matter
• Understand the relationship between different code sections

As detailed in our comprehensive CASp study guide for passing on your first attempt, successful candidates typically spend more preparation time on Domain 2 than any other content area due to its technical complexity and memorization requirements.

Common Exam Mistakes

Avoid these frequent Domain 2 errors:

• Confusing ADA minimums with California Building Code requirements
• Applying residential standards to commercial projects (or vice versa)
• Miscalculating compound requirements that involve multiple specifications
• Forgetting to consider exceptions and alternative compliance paths

Understanding the current CASp pass rate data shows that candidates who master Domain 2's technical requirements significantly improve their overall examination performance, as this domain's objective nature makes it highly predictable for prepared candidates.

For ongoing skill development and practice, our comprehensive practice examination platform provides Domain 2-specific question sets that help reinforce these critical prescriptive requirements through repetitive application in varied scenarios.