Windows and doors are classified into broad performance class categories that describe what type of building the window or door will be located in.
The performance classes are:
- R: Commonly used for one- and two-family dwellings
- LC: Commonly used for low- and mid-rise multi-family dwellings and other buildings where larger size and higher loading requirements are expected.
- CW: Commonly used for low- and mid-rise building where larger sizes, high loading requirements, limits on frame member deflection and heavy use are expected.
- AW: Commonly used for mid- and high-rise buildings to meet limits on deflection and where extreme loading requirements are expected.
To qualify for a given Performance Grade (PG), one or more representative specimens of the product need to pass all required performance tests for the following, in addition to all required auxiliary (durability) tests for the applicable product type and desired Performance Class.
These tests are:
- Operating force (if applicable)
- Air leakage resistance
- Water penetration resistance
- Uniform load deflection test
- Uniform load structural test
- Forced-entry resistance (if applicable)
Each performance class has an entry-level performance grade requirement that will allow a product to qualify for that class. These numbers are based on a minimum design pressure for the structural capacity, air infiltration resistance or water penetration resistance.
These entry-level performance grades are:
- R class: 15 psf (720 Pa)
- LC class: 25 psf (1,200 Pa)
- CW class: 30 psf (1,440 Pa)
- AW class: 40 psf (1,920 Pa)
Design pressure is a rating that identifies the load, induced by wind and/or static snow, that a product is rated to withstand in its end-use application.
Note: Design pressure (DP) is not to be confused with Performance Grade (PG) or structural test pressure (STP). Loads induced by static snow are applicable only to TDDs, roof windows, and unit skylights.
View performance grade ratings for Andersen® products.