10.2 Construction Documents: Elevations

Why Interior Elevations Matter

Interior elevations show the vertical surfaces of a room — walls, millwork, and fixtures — as they would appear if the viewer stood facing the wall. They are critical for communicating material heights, mounting heights, finishes, and fixture locations to the contractor. While plans show layout, elevations answer the "how high?" and "what finishes where?" questions. On the IDIX exam, elevation content tests the designer's knowledge of accessibility mounting heights, critical wall types, annotation standards, and dimensioning.

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What Elevations Show

A complete interior elevation includes:

• Material boundaries and tags — where tile ends and paint begins, keyed to the finish schedule
• Vertical dimensions — heights of wainscot, chair rail, backsplash, counter, upper cabinets
• Mounting heights — fixtures, hardware, signage, grab bars, controls
• Millwork — cabinet faces, countertop profiles, toe kicks, crown mold
• Section symbols — cutting-plane indicators showing where a section is taken
• Keynotes — numbered notes keyed to a legend for specific conditions

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Critical Elevations

Certain walls demand elevation drawings because of their complexity:

• Feature walls — accent walls with special finishes, panel patterns, or integrated lighting
• Wet walls / plumbing walls — walls with plumbing rough-ins requiring precise fixture mounting heights
• Green walls / living walls — walls with irrigation, drainage, and structural support systems
• Millwork walls — walls with built-in cabinetry requiring face elevations and internal sections

A wet wall elevation must show the lavatory centerline, faucet rough-in, mirror height, grab bar locations (if accessible), and accessories (soap dispenser, paper towel, shelf) with dimensions to the finish floor. A green wall elevation must show the structural support framing, irrigation lines, drainage trough, and the planting modules with their vertical spacing.

Mounting Heights Table

Accessibility standards (ICC A117.1-2017, which aligns with the 2010 ADA Standards) mandate specific mounting heights. The exam tests these numbers directly:

These dimensions appear on the toilet room elevations and must be verified against the code during QA/QC. A grab bar at 32" AFF fails because it is below the 33" minimum; a door handle at 50" AFF fails because it exceeds the 48" maximum for operable parts.

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Glazing in Elevations

Glazing — windows and glass partitions — appears in elevations using two conventions:

• Reflected glass: shown with diagonal or hatched lines indicating the reflective quality; the elevation shows the frame and mullion pattern.
• Transparent glass: shown with a light outline only; objects behind the glass may be visible or indicated with dashed lines.

A glazing elevation must also note the glass type (tempered, laminated, insulated), thickness, and any film or interlayer. Safety glazing per IBC Section 2406 is required in doors, adjacent to doors (within 24" of the door plane), and in hazardous locations such as near walking surfaces.

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Material Height Locations

Elevations must dimension the heights where finishes change. Industry-standard heights include:

These heights are not always code-mandated but are established by industry practice and ergonomic standards. The elevation notes them explicitly so the contractor does not guess.

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Toilet Room Elevations

Toilet room elevations are among the most heavily tested on the IDIX exam because they combine accessibility, plumbing, and finish requirements. A complete toilet room elevation set includes:

• Each wall as a separate elevation (4 walls minimum)
• Fixture mounting heights — water closet seat (17"-19" AFF), lavatory rim (34" max AFF), mirror (40" max AFF), grab bars (33"-36" AFF)
• Clearances — grab bar to toilet paper dispenser distance (min 1-1/2" per A117.1 604.7), centerline of water closet (16"-18" from side wall per A117.1 604.2)
• Finish transitions — wainscot or tile height, base, ceiling treatment
• Door — swing direction, hardware height (34"-48" AFF), clearance

The accessible compartment elevation must show the required turning space — 67" diameter in new buildings, 60" in existing buildings per A117.1-2017 Section 304.3.1, or a T-shaped space — plus grab bars on both the rear and side walls and the correct clearance from the water closet centerline to the side wall.

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Section Symbols on Elevations

When an elevation references a section detail, it uses a section symbol — a cutting-plane indicator showing the direction of the section cut. The symbol is typically a circle divided by a line, with one half indicating the section number and the other the sheet reference. The arrow on the cutting plane indicates the direction the section is viewed. On elevations, these symbols appear where a vertical section through the wall would reveal additional construction detail.