Specialty Window Installation in the Chicago Suburbs
Bay windows, bow windows, custom-shaped units, and large picture windows are not standard installations. They require planning from the rough opening out.
What Are Specialty Windows?
Specialty windows is a broad category that includes any window configuration beyond standard flat-wall operable and fixed units. The most common types include bay windows, bow windows, large picture windows, and custom-shaped windows such as arched, circular, triangular, or other non-rectangular units.
Specialty Window Types
Bay Windows
A three-panel unit that projects outward from the building plane at 30 or 45-degree angles, with a large center fixed or double-hung panel and angled side panels. Bay windows create interior space, add natural light, and change the exterior profile of the building.
Bow Windows
Similar to bay windows but composed of four to six panels in a gentle curve, creating a rounded projection from the building facade.
Picture Windows
Large fixed-frame units designed to maximize light and view, often spanning from near the floor to near the ceiling. Picture windows installed at this scale require structural evaluation of the header above the opening.
Custom-Shaped Windows
Arched, circular, triangular, or other non-rectangular units installed in gable ends, above doorways, or as accent elements. These require custom rough opening framing and custom-manufactured units.
Structural and Installation Requirements
Specialty windows, particularly bay and bow units, impose outward loads on the building structure that standard windows do not. A bay window must be supported from below by a cantilevered floor structure or a support beam at the base of the projection, and the roof over the projection must be flashed and integrated into the main roof system. We evaluate the structural conditions at the rough opening before specifying a unit or beginning any framing work.
Flashing a bay or bow window requires more steps than flashing a flat-wall window. The roof of the projection, the angled side panels, and the junction between the projection and the main wall all require careful flashing sequences to prevent water intrusion. We treat every angle change and every material transition as a potential leak path and flash accordingly.
Large picture windows require evaluation of the rough opening header. Removing or enlarging a wall opening to accommodate a larger unit changes the load path in the wall framing. A properly sized and bearing header is required before the new window is installed.
Best Applications
- Bay windows for living rooms, dining rooms, and master bedrooms where a projection adds interior space and curb appeal
- Bow windows for formal living rooms and front facades where a curved profile is architecturally appropriate
- Large picture windows in great rooms, modern open-plan spaces, and commercial storefronts
- Custom-shaped accent windows in gable ends, above entry doors, and in transitional spaces
Frequently Asked Questions
Specialty windows include bay windows, bow windows, large-format picture windows, and custom-shaped units such as arched, circular, or geometric windows. They differ from standard window types in that they often require structural framing modifications, custom rough opening preparation, and more involved flashing sequences than flat-wall operable or fixed units.
A bay window installation starts with structural evaluation of the rough opening and the floor and wall framing at the projection location. If the existing structure cannot support the outward load of the bay, a support ledger or foundation knee wall is added. The rough opening is framed out to the dimensions of the bay unit. The window is set and leveled, the roof of the projection is framed and shingled, all flashing transitions are completed, and interior and exterior trim is finished. It is a more involved project than a standard window replacement. Plan for a multi-day installation.
Yes. The unit cost of specialty windows is higher than standard windows because of custom sizing, additional panels, and more complex framing. Installation labor cost is also higher because of the structural evaluation, framing modifications, additional flashing, and extended trim work required. A bay window project, for example, typically costs two to four times the installed price of a comparable-size standard window replacement. The investment reflects the scope of work involved and the visual and functional impact the window has on the space.
Yes, in most cases. Converting an existing flat-wall window or blank wall section to a bay window requires enlarging the rough opening, evaluating and potentially modifying the structural framing, and supporting the bay projection from below. We assess the specific wall conditions during the estimate to confirm feasibility, identify any structural modifications needed, and provide a complete scope before work begins.