ASCE 7-16 / 7-22 · RISK CATEGORY II
Risk Category II — the standard-occupancy baseline
The default classification for most structures: single- and multi-family homes, offices, retail, and the vast majority of commercial buildings. It is the reference every other category is measured against.
SCOPE · TYPICAL OCCUPANCY
What falls under Risk Category II
Any building whose failure poses no exceptional hazard to human life lands here unless it qualifies for I, III, or IV.
Single-Family Homes
Detached residences, custom and tract homes, manufactured housing on permanent foundations.
RESIDENTIALMulti-Family Residential
Apartments, condominiums, and townhouses with occupancy below assembly thresholds.
RESIDENTIALOffice Buildings
General and professional offices, banks, and business centers with no essential-facility role.
COMMERCIALRetail & Stores
Shops, shopping centers, department stores, and tenant spaces below 300-person occupancy.
COMMERCIALHotels & Restaurants
Transient lodging, dining, and food service with occupant loads below assembly limits.
COMMERCIALWarehouse & Light Industrial
Distribution, storage, and manufacturing without hazardous materials above threshold quantities.
INDUSTRIALASCE 7-22 TABLE 1.5-1 · THE LADDER
Where RC II sits on the risk-category ladder
Higher risk category → a wind map with a longer return period → higher design wind speed. There is no importance-factor multiplier; the category selects which map you read V from.
| Risk Category | Wind Speed Map (MRI) | Primary Use |
|---|---|---|
| I | 300-year MRI map | Low hazard to life — minor agricultural / storage |
| II — Standard BASELINE | 700-year MRI map | Homes, offices, retail, most buildings |
| III | 1,700-year MRI map | Substantial hazard — assembly >300, large schools |
| IV | 3,000-year MRI map | Essential — hospitals, fire/police, shelters |
THE DEFAULT · NO IMPORTANCE FACTOR
Why Risk Category II is the default
Every structure starts at Risk Category II and only moves up or down when specific criteria in ASCE 7 Table 1.5-1 apply. It is the reference point the whole standard is calibrated around.
RC II reads its basic wind speed from the standard 700-year MRI map — the baseline map. Modern ASCE 7 (7-10, 7-16, 7-22) has no wind importance factor; the old Iw was eliminated. Instead, the risk category alone decides which speed map you use, so RC II loads are simply the baseline that Categories I, III, and IV are compared against.
Baseline Reference
The standard against which every other category's loads are described.
Default Classification
Applies unless a building meets the criteria for Category I, III, or IV.
Code-Calibrated Safety
The 700-year MRI map balances life-safety and economy for typical use.
CAUTION · WHEN TO STEP UP
When to step up to III or IV
RC II is the default, but these triggers move a building to a longer-return-period map and higher design loads.
Assembly Over 300
Occupant loads above 300 push a building to Risk Category III regardless of type.
→ RC IIIEssential Facilities
Hospitals, fire and police stations, EOCs, and shelters are Risk Category IV.
→ RC IVMixed Use Buildings
The highest applicable category governs the whole structure unless rated separation allows otherwise.
HIGHEST GOVERNSHazardous Contents
Toxic or explosive materials above threshold quantities raise the category beyond II.
REVIEW USENEXT STEP
Confirm your risk category, then run the numbers
Use the selection guide to verify RC II is correct, then calculate design wind loads with professional ASCE 7 software.
RELATED · RISK CATEGORY RESOURCES
Explore the other categories
Risk Categories Hub
Complete overview of all four categories.
OVERVIEWRisk Category I
Agricultural and low-hazard structures — 300-year MRI map.
RC IRisk Category III
Assembly and substantial-hazard buildings — 1,700-year MRI map.
RC IIIRisk Category IV
Essential facilities — 3,000-year MRI map.
RC IVSelection Guide
How to determine your building's risk category.
START HERE