High Window Solutions

Clerestory Window Design Guide

Complete specifications for HVHZ-compliant clerestory windows. Higher elevations mean higher wind pressures - understand the requirements for these architectural features.

3
Configurations
0
PSF at Height
NOA
Required
Clerestory Window Elevation
Building Section Height Clerestory Zone
Clerestory
Daylight
Height Factor

Configuration Matrix

Side-by-side specifications for HVHZ clerestory window configurations.

Specification
Fixed
Operable
Continuous
Design Pressure (30ft+)
+/-85 PSF
+/-65 PSF
+/-75 PSF
Max Unit Width
12 ft
4 ft
Unlimited
Daylight Factor
High
Med-High
Maximum
NOA Available
Ventilation
Cost per SF
$65-95
$95-140
$120-180

Choose Your Clerestory Type

Fixed Clerestory

Maximum daylight

Frame TypeAluminum/Steel
Glass OptionsImpact IG, Low-E
Max Height6 ft typical
Mullion Span4-6 ft OC
Best For
  • Churches and worship
  • Museum galleries
  • High ceilings

Operable Clerestory

Daylight + ventilation

OperationAwning/Chain/Motor
Glass OptionsImpact IG
Opening4-6 inches typical
ControlManual or automated
Best For
  • Natural ventilation
  • Stack effect cooling
  • Green buildings

Continuous Ribbon

Architectural statement

Frame TypeCurtain wall
Glass OptionsImpact IG, Spandrel
LengthBuilding width
MullionStructural
Best For
  • Modern architecture
  • Commercial buildings
  • Dramatic effect

Clerestory Window FAQs

How does height affect clerestory wind loads?

Wind pressure increases with height. Clerestory windows at 30+ feet elevation can require 20-40% higher design pressures than windows at grade. The velocity pressure coefficient (Kz) increases with height per ASCE 7, requiring stronger frames and thicker glass.

Can operable clerestory windows meet HVHZ requirements?

Yes, but with limitations. Operable clerestory windows in HVHZ typically achieve lower design pressures than fixed units. Awning-style operators are most common, with motorized options for heights over 10 feet. All hardware must be NOA approved.

What framing is recommended for clerestory in HVHZ?

Commercial-grade aluminum framing with thermal breaks is standard. Steel frames may be required for very high design pressures or large spans. Structural mullions connect to the roof structure and must be engineered for both wind and dead loads.

How do you access clerestory windows for maintenance?

Access planning is critical. Options include permanent catwalks, roof anchors for rope access, or interior scaffolding during maintenance. Impact glass reduces cleaning frequency. Consider motorized operators for units over 12 feet high.

Quick Selector
Fixed Clerestory
Highest wind rating
Wind Rating
Daylight
Cost Value

Get Your Clerestory Analysis

PE-stamped wind load calculations accounting for elevation and exposure factors.

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