City of Novato Department of Community Development

Building Division

Information Bulletin
Bedroom Window Replacements
Access and Means of Egress Facilities and Emergency Escapes
(310.4 Uniform Building Code - UBC)

Inspections and approval of window replacements in existing residential buildings based on Section 3403.2 of the Uniform Building Code.

Purpose:

To approve replacement windows in bedrooms of homes built under previous building codes which had different minimum dimensions for purposes of access and means of egress and emergency escapes.

To make sure the replacement windows in bedrooms do not create a condition more hazardous than before the replacement, based on life safety and fire safety.

Policy:

Inspections and approval to be based on the schedule below with year of construction providing the building code requirements for the bedroom windows.

 

Requirements for Replacing Bedroom Windows in Existing Homes

One minimum window per bedroom unless there is a door to the exterior.

Year House Constructed
Does UBC require bedroom egress?
Net Opening Size
Minimum Opening Dimensions
(See Table)
Sill Height
(Maximum From Finished Floor)
Prior to 1964
Window Size
Only
6 Sq. Ft.
(Window Size Only)
None
None
1964 to 1980
Yes

5 Sq. Ft.
(Net Opening)

22 Inches - Height
22 Inches - Width
48 Inches
1980 to Present
Yes
5.7 Sq. Ft.
(Net Opening)

24 Inches - Height
20 Inches - Width
44 Inches

 

Emergency Escape and Rescue Windows

Many fire-related casualties occur when occupants of residential buildings are asleep at the time of the fire. Section 310.4 of the 1997 Uniform Building Code requires that:

Use the chart below to find your window width and height combination to obtain the minimum size window for emergency escape and rescue requirements.

Minimum Opening Sizes of at Least One Bedroom Window
to Meet Requirements for Emergency Escape and Rescue
Width
20
20.5
21
21.5
22
22.5
23
23.5
24
24.5
25
25.5
26
26.5
27
Height
41
40
39.1
38.2
37.3
36.5
35.7
34.9
34.2
33.5
32.8
32.2
31.6
31
30.4
 
Width
27.5
28
28.5
29
29.5
30
30.5
31
31.5
32
32.5
33
33.5
34
34.2
Height
29.8
29.3
28.8
28.3
27.8
27.4
26.9
26.5
26.1
25.7
25.3
25.3
24.9
24.1
24

You need the minimum 20-inch width, plus the minimum 24-inch height, plus the total net clear openable area of 5.7 square feet.

For further information, please contact:

City of Novato, Department of Community Development
City Hall, 901 Sherman Avenue, Novato, CA 94945
Telephone: (415) 897-4341


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