Window schedules consolidate all the information needed to fabricate and install windows: sizes, types, glazing, and hardware. Learning to read them correctly ensures you order the right products and install them in the right locations.

Step 1: Find the Window Mark

Window marks connect the schedule to elevations and plans:

Letter-basedA, B, C or W1, W2, W3

Simple projects

Type + SizeA-3648 (type A, 36"x48")

Shows size in mark

Location-basedN-01, S-01 (North-01, South-01)

Orientation matters

Step 2: Read Window Dimensions

Window sizes may be shown as nominal or rough opening:

Dimension Types

Nominal Size: The named size (3'-0" x 4'-0"), though actual size may vary

Rough Opening (R.O.): Size of the opening in the wall

Frame Size: Actual exterior dimension of the window frame

Glass Size: Visible glass area (daylight opening)

Verify which dimension type is specified. Rough openings are typically 1/2" to 1" larger than frame size for shimming.

Step 3: Identify Window Types

Window operation types affect function and code compliance:

Fixed (F)Non-operable, glass only

Single Hung (SH)Bottom sash moves up

Double Hung (DH)Both sashes move

Casement (C)Hinged at side, swings out

Awning (A)Hinged at top, swings out

Hopper (H)Hinged at bottom, swings in

Sliding (SL)Horizontal slide

Projected (P)Pivots at center

Step 4: Check Frame Material

Frame materials affect performance, cost, and maintenance:

Aluminum (AL)

Durable, low maintenance, may need thermal break

Vinyl (V)

Good thermal performance, limited colors

Wood (WD)

Traditional look, requires maintenance

Clad Wood

Wood interior, aluminum/vinyl exterior

Fiberglass (FG)

Strong, good thermal, paintable

Steel

Fire-rated applications, narrow sightlines

Step 5: Understand Glazing Specifications

Glass performance significantly affects energy efficiency:

IG or IGU

Insulated Glass Unit (double or triple pane)

Low-E

Low-emissivity coating for energy efficiency

Tempered

Safety glass, required at certain locations

Laminated

Safety/security glass with interlayer

Tinted

Colored glass for solar control

Spandrel

Opaque glass to hide structure

Step 6: Note Performance Values

Energy code compliance depends on these ratings:

U-Factor

Heat transfer rate. Lower is better (0.25-0.40 typical)

SHGC

Solar Heat Gain Coefficient. Lower numbers block more heat

Visible Transmittance. Higher numbers mean more light

STC

Sound Transmission Class. Higher numbers block more noise

Step 7: Verify Against Elevations

Cross-check the schedule against building elevations:

Window marks on elevations match the schedule

Sizes appear correct in proportion to the building

Head and sill heights are consistent

Mullion patterns match window types

Operable windows are shown where required for egress

Verify Window Schedules Automatically

Checking that window schedules match elevations and plans is tedious but critical. Articulate's AI can automatically cross-reference your schedules and drawings to catch discrepancies.

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How to Read a Window Schedule