Bay windows feature three panes with distinctive sharp angles, creating bold, striking architectural statements.

Each bay window pane can be customized with grills, casings, brickmoulds, and trims for personalized style.

Bay windows can be assembled with operable casement, awning, and hung units, as well as fixed units such as fixed casement and picture windows..

Bow windows, formed by five or more panes, create a smooth, elegant curve that softens exterior lines and adds a naturally flowing, refined appearance.

Bay and Bow Windows

Q: Where does Window Force supply bay and bow windows in Canada?

Bay and bow assemblies are manufactured at our 80,000 sq ft facility in Vaughan, Ontario, and shipped to dealers and projects across Canada, including markets in Halifax, Moncton, Montréal, Québec City, Winnipeg, Regina, Saskatoon, Red Deer, Kelowna, and Victoria.

Bay and bow windows are multi-unit projection assemblies that extend outward from the wall plane, combining fixed and operable window units to create a wider view, expanded interior space, and additional natural light. A bay window uses three or more angled panels at a fixed angle; a bow window uses four or more panels in a gradual curve. Both are assembled from Classic Series units and supplied with integrated brickmould and seat board assemblies. Hardware type depends on the operable units integrated into the assembly.

Panoramic views

Expanding livespace

Sealed unit

Internal chambers

uPVC material

Jamb extensions

Fusion welded corners

Inside trim

Outside vinyl brickmoulds

Beautiful panoramic
viewing angles

Energy-efficient
sealed units

Reinforced structural
frame system

Optional operable
windows for airflow

Key
Features

Multi-unit projection assemblies that extend outward from the wall plane

Bay window: 3-lite configuration with angled side panels at custom angles

Bow window: 4 to 8-lite configuration in a graduated curve

Combines fixed and operable units (casement, awning, or hung)

Structural mullion integration between units

Multi-unit load distribution across the head and seat board

Reinforced head and seat board system

Supplied with integrated brickmould and seat board assemblies

Double or triple glazed, argon fill standard

Custom angle configurations available

How It Works

Bay and bow windows are assembled from individual Classic Series window units connected by structural mullions and anchored to a reinforced head board at the top and a seat board at the bottom. The head board spans the full width of the assembly and distributes the window load to the rough opening; the seat board provides the structural base for the projecting assembly. Operable units (casements, awnings, or hung windows) are integrated into the assembly wherever ventilation is needed. Fixed units fill the remaining positions. The angle between panels in a bay assembly is set at manufacture — standard angles are typically 30° or 45° for the side panels, but custom angles are available.

Where It Works Best

Bay windows are a traditional architectural feature in Victorian, craftsman, and colonial homes. The projecting bay creates a window seat or shelf at the interior sill level, which adds usable space and a natural focal point in a living room, dining room, or bedroom. Bow windows provide a softer, more gradual projection suited to curved elevations and contemporary interpretations of the bay window theme. Both configurations add depth to a facade and increase daylight penetration into a room by bringing the glass closer to the outdoor light source. They are typically placed in primary living spaces, dining rooms, and master bedrooms.

Series Availability

Ultraslim Series

Reduced visible profile (2 7/8″) with deeper frame depth (4 9/16″)
Maximized glass area and clean sightlines
Hidden gasket design
Optimized for new construction and larger openings
Contemporary architectural appearance
Bay and bow assemblies available for new construction

Explore the Ultraslim Series

Classic Series

Proven standard-profile frame design (3 1/4″ platform)
Optimized for retrofit and replacement applications
Reliable compatibility with a wide range of installation conditions
Balanced performance and traditional aesthetics
Frame depth 3 1/4″
Double-pane 13/16″ overall or triple-pane 1 5/16″ overall
Hardware type dependent on integrated operable units

Explore the Classic Series

Frame & Structural Design

uPVC The window system is manufactured using uPVC vinyl extrusion supplied by Vision Extrusions Group, a North American manufacturer specializing in high-performance vinyl profiles. The material is formulated to provide long-term dimensional stability, impact resistance, and resistance to discolouration under varying environmental conditions.

Internal Chambers These windows have the highest number of internal chambers, giving them out-standing insulation and sound abatement qualities, as well as thermal efficiency and increased sturdiness.

Fusion Welded Corners Provide attractive appearance & eliminate the need for adhesive and sealants. There are no imperfections on the completely watertight and airtight surface, Interior walls are also welded.

Outside Vinyl Brickmould

Inside Trim

Jamb Extensions A choice of maintenance-free uPVC, solid vinyl and wooden jamb extensions, frame moldings and corner blocks are available to enhance inside finish.

Sealed Units Sealed glass unit has 13/16” overall thickness. Depending on the model, glazing and different types and thicknesses can be applied, including double, triple and Low-E glazing (3/4” to 1-1/8)

Hidden Gasket Concealed sealing without visible rubber lines.

Reinforced head board spans the full assembly width and distributes load to the rough opening header

Seat board provides a structural base for the projecting assembly and the interior window seat or sill

Multi-unit load distribution across the full assembly rather than relying on any single unit

Custom angle configurations available for the side panels of bay assemblies

Structural mullion integration between adjacent units transmits lateral and vertical loads across the assembly

Compatible with operable casement, awning, and hung units integrated within the bay or bow configuration

Hardware and Operation

Hardware type in a bay or bow window depends on the operable units integrated into the assembly. Casement units use Encore operator systems and multi-point locking hardware. Awning units use the same hardware system as standalone awning windows. Hung units use cam lock and balance cartridge hardware. Fixed units within the assembly have no hardware. Contact Window Force with your assembly configuration to confirm hardware specifications.

Glazing Options

LoĒ-180

Surface 2

High solar heat gain for north and east-facing elevations

LoĒ-272

Surface 2

Solar control for south and west-facing elevations

LoĒ-366

Surface 2

Advanced solar control for high-sun conditions

LoĒ-i89

Surface 4/6

Interior heat reflection for U-factor reduction

Neat+

Self-cleaning coating for exterior surface applications

Safety

Tempered safety glass where required by code on lower panels

Security

Laminated glass available for security and sound attenuation on fixed panels

Spacer

Technoform rigid thermoplastic or Super Spacer flexible foam

Double-pane sealed IGUs (13/16″ overall) or triple-pane (1 5/16″ overall)

Argon gas fill comes standard in every unit to improve the overall thermal performance

Glazing can be specified independently for each panel within the assembly

Configurations

All Window Force window types support standardized customization options across Classic and Ultraslim Series, ensuring compatibility and clean integration across mixed window projects.

Colour Options

At Window Force, we offer a carefully curated palette of durable, fade-resistant colours designed to match any architectural style, from classic to contemporary.

Explore Colour Options

Glass Options

We provide a wide range of advanced glass types tailored for modern window systems. From partially transparent decorative glass with artistic textures for enhanced privacy, to high-performance Low-E coatings that improve energy efficiency.

Explore Glass Options

Jambs, Casing, Brickmoulds

Jambs, casings, and brickmoulds come in a variety of sizes to suit different needs, and they're available in a full color palette to complement your design vision. These components provide versatile options for functional and aesthetic window finishing.

Explore Options

Grills Options

If you want to enhance your windows with decorative pane patterns, we offer a flexible range of interior grill shapes to choose from — from the most common layouts to fully custom designs made to fit your style.

Explore Grills Options

Energy Performance

Series	Glazing	U-Factor, W/(m²·K)	SHGC	Energy Rating
Classic, Picture Panels	Double Pane	1.21 – 1.51	0.35 – 0.59	34 – 44
Classic, Picture Panels	Triple Pane	0.83 – 0.86	0.30 – 0.31	38 – 40
Classic, Fixed Casement Panels	Double Pane	1.19 – 1.47	0.32 – 0.54	32 – 46
Classic, Fixed Casement Panels	Triple Pane	0.88 – 0.98	0.27 – 0.44	34 – 41
Classic, Casement Units	Double Pane	1.28 – 1.49	0.42 – 0.47	34 – 36
Classic, Casement Units	Triple Pane	0.95 – 0.98	0.23 – 0.24	31 – 33
Classic, Awning Units	Double Pane	1.3 – 1.5	0.42 – 0.48	34 – 35
Classic, Awning Units	Triple Pane	0.95 – 1.0	0.23 – 0.24	31 – 32
Classic, Single Hung Units	Double Pane	1.48 – 1.51	0.53 – 0.55	35 – 38
Classic, Double Hung Units	Double Pane	1.48 – 1.51	0.53 – 0.55	35 – 38

Performance of a bay or bow assembly is determined by the individual units within it. The overall assembly thermal performance is calculated as a weighted average across all panel areas.

Size Limitations

The table below outlines standard high fix window and casement fix size limitations for the Canadian market. Maximum dimensions depend on glazing configuration and structural performance requirements.

Series	Pane	Width, min – max	Height, min – max	Max Sq.Ft.
Classic, Picture Panels	Double Glass	12" – 90"	12" – 90"	30 sq.ft.
Classic, Picture Panels	Triple Glass	12" – 60"	12" – 60"	25 sq.ft.
Classic, Fixed Casement Panels	Double Glass	12" – 120"	12" – 120"	50 sq.ft.
Classic, Fixed Casement Panels	Triple Glass	12" – 96"	12" – 96"	33 sq.ft.
Classic, Casement Units	Double Glass	15.5" – 38"	18" – 72"	17 sq.ft.
Classic, Casement Units	Triple Glass	15.5" – 36"	18" – 64"	14.5 sq.ft.
Classic, Awning Units	Double Glass	14.5" – 50"	14" – 60"	17 sq.ft.
Classic, Awning Units	Triple Glass	14.5" – 50"	14" – 50"	16 sq.ft.
Classic, Single Hung Units	Double Glass	15" – 46"	27" – 66"	21 sq.ft.
Classic, Double Hung Units	Double Glass	15" – 46"	28" – 58"	21 sq.ft.

Actual size limits may vary based on series selection, glass thickness, and project-specific requirements.

Warranty Coverage

Full warranty details

Up to 25 years: 100% factory coverage, 0% dealer/client
25–30 years: 80% factory coverage, 20% dealer/client
Over 30 years: 25% factory coverage, 75% dealer/client

Glass warranty: 10-year non-prorated sealed unit warranty covering seal failure, internal condensation, and visual obstruction between glass panes

Window Force provides warranty coverage on materials and manufacturing defects under normal use and service conditions. Claims are handled directly through Window Force. Inspection and resolution are coordinated by the factory. Repair or replacement is determined based on assessment.

Covered:

Manufacturing defects in window components, sealed glass unit failure under normal conditions, hardware performance under standard use

Not Covered:

Installation-related issues, damage during handling or after delivery, structural movement or excessive humidity, misuse or modification

Frequently Asked Questions

Everything you need to know about the product and billing.

What is the difference between a bay window and a bow window?

A bay window uses a small number of angled panels — typically three — meeting at fixed angles, commonly 30° or 45° at the side panels. The result is a squared-off projection from the wall plane. A bow window uses more panels (four to eight) meeting at shallower angles, which creates a curved or gradual arc projection. Bay windows have a more angular, architectural look; bow windows have a softer, more flowing appearance. Both can integrate operable and fixed units.

How many units can a bow window include?

Window Force bow windows support up to 8-lite configurations. The number of lites determines the degree of the curve — more panels produce a tighter, fuller arc, while fewer panels produce a shallower curve. The specific angle between panels is set at manufacture based on the required projection and the total assembly width.

What operable window types can be integrated into a bay or bow assembly?

Casement, awning, and hung units can all be integrated into bay and bow assemblies. The choice of operable type depends on the design and the position within the assembly. Side panels in a bay window are often casements, since their compression seal performs well at the angled position. Centre panels are often fixed. Awning units can be used where a top-hinged option is preferred.

Do bay and bow windows include a seat board?

Yes. Window Force bay and bow assemblies are supplied with an integrated head board and seat board system. The seat board forms the structural base of the projection and the interior sill or window seat surface. The head board spans the assembly width and connects to the rough opening header. Both boards are reinforced for the multi-unit load distribution across the assembly.

Is triple-pane glazing available in bay and bow windows?

Yes, for any casement or awning units within the assembly, and for fixed panels. Hung units within a bay or bow assembly are double-pane only. Triple-pane on the operable units provides lower U-factors and better noise reduction, which is particularly useful on bay windows facing a street or an active outdoor space.

Does a bay or bow window require a structural header in the wall?

Yes. Removing the section of wall for a bay or bow installation requires a header sized to carry the load of the wall above the opening. The size of the header depends on the span, the loads above, and the local building code. This is a structural decision that must be confirmed with a qualified contractor or structural engineer before the rough opening is framed. Window Force does not supply structural headers — they are a wall construction component, not a window component.

Where does Window Force supply bay and bow windows in Canada?

Bay and bow assemblies are manufactured at our 80,000 sq.ft. facility in Vaughan, Ontario, and shipped to dealers and projects across Canada, including markets in Halifax, Moncton, Montréal, Québec City, Winnipeg, Regina, Saskatoon, Red Deer, Kelowna, and Victoria.

Bay and Bow Windows