Business & Developer Services Division
3rd Floor, City Hall
808 W. Spokane Falls Blvd
Spokane, Washington 99201
509.625.6300
SFR-21
Window Replacement Policy
A Building Permit is required to replace an existing window (International Building Code
Section 105.1) when any of the following conditions are met:
1. The existing window and frame are removed and a new window and frame are installed in the existing
rough window opening. In a bedroom, as long as the existing window was legal when installed, the new,
same type window and rough opening size window, will be considered legal as it does not increase the
existing hazard (IBC Section 3403.3).
2. The existing window and frame are removed and the rough window opening size is changed. If this is a
bedroom egress window, the window must meet the current egress window opening requirements.
Minimum 20-inch wide net clear opening, minimum 24-inch high net clear opening, with a net clear
opening area of a minimum 5.7 square feet (821 square inches) (IBC Section 102.5.2-5.0 square feet
on grade level egress windows).
3. The existing window and stops are removed, the existing frame is left in place and a new window and
frame is inserted within the existing window frame. If the window opening size in a bedroom is changed
by this installation, it must meet current egress window requirements (IBC Section 310.4 and 3403.2).
4. Replacement windows should meet the minimum U factor of 0.35 as required by
Table 6-2 in the Washington State Energy Code.
If just the glass is replaced within an existing window, a Building Permit is not required. The installation or
replacement of glass shall be as required for new installations per IBC Section 3405 (i.e., if the original glass
was single- or double-pane glazing and the current code required tempered glazing for that location, the new
glass is required to be tempered glazing).
