ICC Updates Window Opening Control Devices/Minimum Window Sill Height Code

January 5th, 2010 by Editor

A proposal to provide an exception to the minimum window sill height requirement for operable windows that are equipped with ASTM F2090-compliant Window Opening Control Devices (WOCD) was approved at the recent International Code Council hearings in Baltimore.

Proposal RB123 was approved as modified as follows in Part I of the International Residential Code:

R612.3 Window opening control devices. When required elsewhere in this code, window opening control devices shall comply with ASTM F 2090. The window opening control device, after operation to release the control device allowing the window to fully open, shall not reduce the minimum net clear opening area of the window unit to less than the area required by Section R 310.1.1. The device or any portion thereof shall not project more than 1 inch into the required net clear opening for a length not exceeding 3 inches when the window is in the fully open position.

“The committee feels this is a good change and the ICC CTC and industry has reached a consensus for a solution to the window opening control devices and achieves consistency with the IBC,” writes the committee in the final report from the hearings posted on the ICC website. “The modification requires all window opening control devices to comply with the standard and eliminate the proposed language about hardware projection.”

In PART II of the International Building Code (IBC) Fire Safety, the proposal was approved as modified to the following:

1405.13.2.1 Window opening control devices. When required elsewhere in this code, window opening control devices shall comply with ASTM F 2090. The window opening control device, after operation to release the control device allowing the window to fully open, shall not reduce the minimum net clear opening area of the window unit to less than the area required by Section 1029.2. The device or any portion thereof shall not project more than 1 inch into the required net clear opening for a length not exceeding 3 inches when the window is in the fully open position.

The committee agreed that it was appropriate to have consistency between the IRC and the IBC with respect to the provisions for window sills and window opening control devices. The modification removes projection requirements that have not been justified, according to the committee’s report.

Another proposal (RB122) that would raise the minimum sill height for operable windows from 24 inches to 36 inches also was presented. This was disapproved for the IRC, but approved for the IBC.

The IRC committee stated its reason for the disapproval was “the 24-inch height has not been in use long enough to accumulate needed data to justify a change to 36 inches.” However, when the IBC approved it, the committee noted that “increasing the current 24 inch sill height requirement to 36 inches was justified by the data submitted by the proponent.”

The above code changes will undergo further review in Dallas May 14–23, 2010. The public comment deadline is February 8, 2010. (CLICK HERE to download the public comment form.)

For more information about WOCD’s and sill heights, CLICK HERE for an article written by Chuck Anderson, AAMA’s codes and industry affairs manager.

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