EXISTING HOMES
WI 1.0—Introduction
Window requirements shall apply to patio doors unless otherwise stated. Windows shall be installed and supported according to the manufacturer’s specifications. If window-weight cavities exist and are accessible, the weights shall be removed and the cavity shall be filled with insulation. Windows shall be reasonably sealed to prevent air infiltration. All incentive-qualifying windows must meet the applicable requirements—unless a waiver is approved in advanced by Existing Homes (see section IN 1.5)—to be considered a complete measure. Windows shall be installed to prevent heat loss from conditioned space to the outside of the house. Basements containing HVAC ducts or which have a direct access to the interior conditioned space of a home shall be considered conditioned space.
Overview for all glazing systems:
- Safety glazing shall be used where required by current state code. See sections on safety glass for details.
- Windows shall operate smoothly and safely.
- Screens shall be furnished with all operable windows.
- Exterior wood, including frame, sash, trim, stops and sills shall be, at a minimum, caulked and primed.
- Hardware and fasteners shall be aluminum, stainless steel or other noncorrosive materials.
- Gaps of over 3/8” between the exterior siding and the window shall be covered with solid trim material. Exterior or interior voids over 3/8” in depth or width shall be filled with window-manufacturer approved materials, such as backer rod, nonexpanding foam or similar product prior to caulking, if caulking will be applied.
Window incentives shall be paid only for windows of the original dimensions, except when window area must be increased to meet egress requirement.
WI 1.1—General Requirements for Glazing
Replacement windows shall be certified and labeled for U-factor in accordance with the simulation, testing and certification procedures of the National Fenestration Rating Council Incorporated, or NFRC.
Windows shall meet U-factor requirements detailed by the current program information document.
The following window types are common retrofits. For windows not meeting these descriptions, contact Existing Homes for information on incentive compliance.
WI 1.2—Block Windows
Block windows do not have nailing flanges. Block windows shall be secured to the rough opening within 4” of each side corner and a minimum 12” on center thereafter. Block windows shall not be smaller than the interior jamb and shall fit tightly with it. Gaps of over 3/8” between the exterior siding and the block window shall be trimmed. Exterior or interior voids over 3/8” in depth or width shall be filled with backer rod prior to caulking. Exposed block windows shall be flashed (see Illustration WI 1.5—Exposed to the Elements).
The flashing shall tuck behind the exterior siding at least 1”. Flashing shall have a downward bending lip of at least ¼” on the front and ends. Block windows shall be supported at the fin line.
WI 1.3—Surface-Mounted Windows
Existing Homes does not allow surface-mounted windows on site-built houses or on manufactured homes with wood siding. This section does not apply to Stucco-mounted windows. Surface-mounted windows designed for this purpose may be installed on manufactured homes with aluminum siding.
WI 1.4—Cut-Out Windows
Cut-out windows have nailing flanges and are installed on the sheathing or framing. The tops of cut-out windows shall have metal flashing inserted behind the existing siding material and over the head trim piece, unless the tops of the windows are protected by an overhang (see Illustration WI 1.5—Exposed to the Elements).
The sides of cut-out windows shall be flashed with 15 lb. felt or an equivalent building paper. The building paper shall be inserted underneath the existing siding and building paper and over the fins of the windows. The bottoms of cut-out windows shall be flashed with 15 lb. felt or an equivalent building paper. The building paper shall be inserted underneath the existing siding and over existing building paper and under the bottom fins of the windows.
All filler and trim pieces must be thoroughly caulked. The flashing shall tuck behind the exterior siding at least 1”. Flashing shall have a downward bending lip of at least ¼” on the front and ends.
Illustration WI 1.4
WI 1.5—Exposed to the Elements
To determine if a window is exposed to the elements, use the two-to-one ratio system. See the following illustration:
Illustration WI 1.5
WI 1.6—Stucco-Mounted Windows
Stucco-mounted windows are replacement windows that mount directly to the frames of existing windows.
Seal the fin of the new window and the outer flange of the existing window with a sealant designed for this purpose. The sealant must stick to the vinyl fin and the aluminum flange. The lip of the existing aluminum flange shall be at least 3/8” wide. The gap between the frame of the replacement window and the interior trim shall be caulked. If the gap exceeds ¼”, the gap shall be filled with closed-cell backer rod, or chinked and caulked. The gap shall then be covered with a permanently attached trim material and caulked on the top and bottom seams.
The bottom rail of the existing window should be cleaned to prevent blockage of weep holes. The miter joints on the fin of the replacement window shall be smooth so the corners do not bulge from the aluminum window.
WI 1.7—Miscellaneous Requirements
The bottom rail of a patio door shall be firmly supported within 1/2” of the exterior edge of the frame. Any wood touching the ground or cement shall be pressure-treated.
WI 1.8—Health and Safety Requirements
All windows shall meet the following egress and safety-glazing specifications. Installers are required to meet current state or local code if it becomes more restrictive than Existing Homes specifications.
WI 1.9—General Safety Glazing Requirements
Safety glazing requirements shall apply to replacement windows and patio doors, multi-glazing inserts and storm windows.
All windows shall meet the following egress and safety glazing specifications. If state or local code becomes more restrictive than HES specifications, then installers shall be required to meet current state or local code.
Each lite requiring safety glazing shall bear the manufacturer's permanent safety glazing label. This label of identification shall be etched or ceramic-fired on the glazing and be clearly visible in one of the corners of the lite.
WI 1.10—Hazardous Locations Requiring Safety Glazing
The following shall be considered specific hazardous locations for the purpose of glazing:
- Glazing in entry doors
- Glazing in patio doors and French doors
- Glazing in storm doors
- Glazing in a fixed or operable panel
that meets all of the following conditions:
- The exposed area of an individual pane is greater than 9 sq. ft.
- The bottom edge is less than 18” above the floor.
- The top edge is greater than 36” above the floor.
- One or more walking surfaces are within 36” horizontally of the glazing.
In lieu of installing safety glazing in this situation, a protective bar may be installed on the accessible side(s) of the glazing 34” to 38” above the floor. The bar shall be capable of withstanding a horizontal load of 50 pounds per lineal foot without contacting the glass and be a minimum of 1.5” in height.
Illustration WI 1.10A
- Glazing in hot tubs, whirlpools, saunas, steam rooms, bathtubs and showers (where the bottom edge of the glazing is less than 60” above the drain inlet.
Illustration WI 1.10B
Glazing in a fixed or operable panel adjacent to a door where the nearest vertical edge is within a 24” arc of the door in a closed position and whose bottom edge is less than 60” above the floor or walking surface.
Illustration WI 1.10C
Illustration WI 1.10D
WI 1.11—Miscellaneous Safety Glazing Requirements
Any glazing panel that can be moved into a hazardous area (e.g. the operable panel of a horizontal sliding window) shall also be made of safety glazing. However, any glazing panel which cannot be moved into a hazardous area (e.g. the upper panel of a single-hung window) does not need to be made of safety glazing.
Fixed glazing panels contained in one window surround, but separated by structural mullions, do not need to be safety glass if they are not located in a hazardous area.
Safety glazing will not be required in the following instances:
- Openings
and doors through which a 3-inch sphere
is unable to pass
- Leaded
glass panels
- Faceted
and decorative glass
WI 1.12—Emergency Egress Openings
Every sleeping room shall have at least one operable window or exterior door approved for emergency egress or rescue. The units shall be operable from the inside to a full, clear opening without the use of separate tools. Where windows are provided as a means of egress or rescue, they shall have a sill height of not more than 44” above the floor.
All egress or rescue windows in sleeping rooms shall have a minimum net clear opening of 5.7 sq. ft. The minimum net clear opening height dimension shall be 24”. The minimum net clear opening width dimension shall be 20”. Windows where the bottom edge is level with the ground may have a minimum net clear opening of 5 sq. ft.
An energy-efficient window with the same frame opening dimensions and emergency exit opening as the original may be used as a replacement for windows that are noncompliant with emergency exit provisions. If a replacement window has the same frame opening dimensions but a smaller emergency exit opening than the original, it shall not be replaced unless the smaller exit opening still meets the current emergency exit opening requirements.