ASCE 7-22 Ch. 26–30 • IBC §1609 • ACI 318-19 Ch. 17
Wind Design & Wind Load Calculations for Equipment and Structures
PE/SE stamped wind load calculations and attachment design for rooftop equipment, screen walls, antennas, and non-building structures. Code-compliant under ASCE 7-22 Chapters 26–30 and IBC §1609 — from velocity-pressure derivation to stamped anchorage details and plan-check response.
What is wind design?
Wind design is the structural analysis that determines the lateral and uplift forces an exposed component or structure must resist under code-prescribed wind loads. For rooftop MEP equipment, screen walls, antennas, signs, and non-building structures, the wind load calculation drives the size of the anchors, the attachment frame, and — in many cases — the equipment housing itself.
Per IBC §1609 and ASCE 7-22 Chapters 26–30, wind must be checked alongside seismic for any equipment or structure that resists lateral load. In coastal and hurricane-prone regions, wind almost always controls. In sheltered high-seismic sites, seismic may control. Either way the larger demand drives the design — and we deliver both calculations in a single stamped package.
Common wind-design mistakes we see
- • Using seismic Fp without checking the wind force on the same anchor
- • Missing GCr amplification on rooftop equipment under ASCE 7-22 §29.4.1
- • Calculating wind on the housing only — ignoring uplift on horizontal surfaces
- • Wrong exposure category (B used in open-coast Exposure D zones)
- • Manufacturer attachment details that lack site-specific velocity pressure
- • Screen walls designed as MWFRS instead of higher C&C pressures
Wind design services
PE/SE stamped wind load calculations and attachment design for MEP contractors, equipment manufacturers, and AHJ submittals.
Wind Load Calculations (ASCE 7-22)
Site-specific velocity pressure, gust factor, and force coefficient derivations for components, cladding, rooftop equipment, and other structures.
Rooftop Equipment Anchorage
PE/SE stamped attachment and anchorage design for RTUs, condensers, chillers, fans, and air-handlers under combined wind + seismic demand.
Non-Building Structures
Wind design for screen walls, antennas, monopoles, signs, canopies, and equipment platforms per ASCE 7-22 Chapter 29.
Stamped Submittal Packages
Calculation report, anchor design per ACI 318-19 Ch. 17, and stamped detail sheets ready for IBC and OSHPD/HCAI plan check.
Codes & standards we design to
Wind loads — general requirements (V maps, exposure, Kz, Kzt, Kd, Ke)
MWFRS — Directional and Envelope procedures
Other structures and rooftop equipment (GCr, Af projected area)
Components & Cladding pressures (parapets, screens, signs)
International Building Code wind design requirements
Anchorage to concrete (tension, shear, combined)
Wind design — frequently asked questions
What is wind design and when is a wind load calculation required?
Wind design is the structural analysis that determines the lateral and uplift forces an exposed component or structure must resist under code-prescribed wind loads. Per IBC §1609 and ASCE 7-22 Chapters 26–30, a wind load calculation is required for any rooftop equipment, screen wall, antenna, sign, canopy, or non-building structure whose attachment, anchorage, or framing is governed by wind. For most California and high-wind regions, the controlling design demand on rooftop MEP equipment is wind, not seismic — even when both must be checked.
How is wind load calculated under ASCE 7-22?
ASCE 7-22 calculates the design wind pressure as p = qz × G × Cf for components and cladding (Ch. 30) and as F = qz × G × Cf × Af for rooftop equipment and other structures (Ch. 29). qz is the velocity pressure (qz = 0.00256 × Kz × Kzt × Kd × Ke × V²), G is the gust effect factor, Cf is the force coefficient (a function of geometry and aspect ratio), and Af is the projected area. For rooftop equipment under 0.1·Bh × Lh, ASCE 7-22 §29.4.1 requires GCr force coefficients that are amplified above the roof.
Do small rooftop units (RTUs, condensers, exhaust fans) need a wind calculation?
Yes. ASCE 7-22 §29.4.1 explicitly covers rooftop structures and equipment with no minimum size threshold for IBC compliance. Even small condensers and exhaust fans require an attachment design that resists the calculated wind force on the projected area, plus uplift on horizontal surfaces. We routinely produce stamped one-page wind anchorage details for units as small as 100 lb up to chillers and air-handlers over 20,000 lb.
Is wind or seismic the controlling load on my equipment?
It depends on site location, equipment height above grade, basic wind speed (V), and seismic design category. As a rule of thumb, in coastal and hurricane-prone regions (V > 130 mph) wind usually controls anchorage of exposed rooftop equipment. In high-seismic California sites with sheltered or low-aspect equipment, seismic typically controls. ASCE 7-22 requires both load cases be checked and the larger demand used for the anchor and attachment design — we deliver both calculations in a single stamped package.
What is the difference between MWFRS and Components & Cladding (C&C)?
Main Wind-Force Resisting System (MWFRS, ASCE 7-22 Ch. 27–28) is the global lateral system of a building or non-building structure — frames, shear walls, and diaphragms. Components & Cladding (C&C, Ch. 30) covers individual elements receiving wind directly — roofing, parapets, screens, signs, equipment doors. Rooftop equipment falls under Ch. 29 (other structures). For attachment design we use the higher of the C&C or Ch. 29 demand at the equipment location.
Do you provide wind design for hurricane-prone regions and Risk Category IV?
Yes. Our PE/SE engineers are licensed in California, Florida, Texas, and 30+ other states. We routinely produce wind anchorage and attachment calculations for hospitals (Risk Category IV, Iw = 1.0 with full demand), data centers, telecom monopoles, and emergency-power equipment in V = 150–180 mph zones. Submittals include the ASCE 7-22 hazard tool excerpt, wind pressure derivation, anchor design per ACI 318-19 Chapter 17, and stamped drawings.
Can you stamp drawings produced by the equipment manufacturer?
Yes — we offer PE/SE review and stamping of manufacturer-supplied attachment drawings when the calculations are complete and verifiable. If the manufacturer only provides a general arrangement, we produce the attachment design from scratch using the unit's weight, projected areas, and center of gravity. Either way the deliverable includes a wind load calculation report, anchor design, and stamped detail sheet ready for plan check.
How fast can you turn a wind load calculation?
Single-unit rooftop equipment wind anchorage with a known site address: 3–5 business days for a stamped package. Multi-unit projects, screen walls, or non-building structures: 1–2 weeks depending on scope. Rush 48-hour turnarounds are available for change-order and plan-check response work. Quote requests submitted with equipment cut sheets and a site address get a fixed-fee response within 24 hours.
Need a stamped wind design package?
Send us your equipment cut sheets and a site address. Fixed-fee quote in 24 hours, stamped package in 3–5 business days for single-unit jobs.