WINDOW STYLES

Bay & Bow Windows

The architectural statement. Bay and bow windows project outward from the wall, adding interior space, dramatic light, and a panoramic view that flat windows can’t deliver.

[Hero image: A bay or bow window projecting outward on a Pacific Northwest home, ideally with interior bench seating]

Bay and bow windows are multi-unit assemblies that project outward from the home’s exterior wall, creating a small bumped-out alcove of glass. A bay window typically uses three units at angled joints (a flat picture window in the middle with two angled units flanking it). A bow window uses four to six units in a gentle curve. Both add usable interior floor space, often used for window seats, plant displays, or breakfast nooks, and both create a dramatic exterior architectural feature.

Bay versus bow

A bay window has three units with sharp angled joints, usually a flat picture window in the middle and two angled units (often casements or double hungs) on either side. The result reads as a clean three-sided projection. A bow window has more units (typically four to six) arranged in a gentle arc, which gives a softer rounded shape. Bays project further out and have a sharper architectural character; bows are subtler and curve smoothly.

What you gain

Square footage, light, and view. The projection adds roughly 12 to 36 inches of interior floor space, perfect for a window seat or display ledge. Light pours in from three (bay) or more (bow) angles, which transforms a room. The view widens because you’re looking through multiple panes facing different directions instead of one flat plane.

Structural and installation considerations

Bay and bow windows are heavy multi-unit assemblies that project beyond the home’s exterior wall. They need adequate structural support beneath, often including a small roof above (called a cap), and they require careful framing to integrate with the existing wall. We handle the full installation including cap roof framing if needed. Bay and bow projects are typically more involved than standard window replacements.

Operating versus fixed configurations

On a bay window, the flanking units (the angled ones on either side of the center) are usually operating windows for ventilation, while the middle picture window is fixed. The configuration is flexible: you can specify casements, double hungs, or sliders for the flanking units depending on your preference. Bow windows can be all-fixed for maximum view, or alternate fixed and operating units around the curve.

Series we install in this category

Three of our series build bay and bow window assemblies: Milgard Tuscany, Cascade Series, and Ply Gem MIRA. The assembly typically uses a picture window in the middle with casements or double hungs flanking, all built in the same series for visual consistency.

MILGARD

Premium

Tuscany

The PNW favorite. Premium vinyl with a traditional look.

Wider frame with shadow lines that mimic wood
Smooth folding nesting handle
Full Lifetime Warranty plus glass breakage

Best for: Traditional and transitional homes where you want premium vinyl with traditional sightlines.

CASCADE

Premium

Cascade Series

Northwest manufactured. Equal sightlines that capture the wood window look.

Engineered specifically for western US climates
AutoLock self-latching hardware
AAMA and NFRC certified

Best for: PNW homes where regional manufacturing and climate-specific engineering matter.

PLY GEM

Luxury

MIRA

Top of the line. Real wood interior, aluminum-clad exterior.

Solid wood interior, stainable to match your home
46 exterior color options
Up to 4x more efficient than single-glazed

Best for: High-end remodels and custom homes where the interior look matters as much as the exterior performance.

Which one is right for you?

Tuscany is the most popular choice for traditional and craftsman homes, with the wider frame profile that suits the architectural drama of a bay window. Cascade Series is the right pick if Pacific Northwest manufacturing and the equal sightline aesthetic matter to you. MIRA is the high-end option, with a real wood interior that’s particularly striking on a bay or bow assembly. We’ll walk through configuration options and structural considerations during your consultation.

Common questions

How much do bay and bow windows cost compared to flat windows?

Significantly more. You’re buying three to six window units in one assembly, plus the structural support and exterior cap roof in many installations. Expect bay and bow projects to run 3 to 6 times the cost of a single equivalent flat window. They’re a meaningful investment, justified by the architectural impact and added interior space.

Will a bay or bow window require structural work to my home?

It depends on the existing opening. Replacing an existing bay or bow with a new one of the same size is straightforward. Adding a new bay or bow where one didn’t exist before requires enlarging the wall opening, adding structural support beneath the projection, and often building a small cap roof above. We handle all of this and will scope the work specifically for your home during the consultation.

Do bay and bow windows leak more than flat windows?

Not when installed correctly. The risk areas are the cap roof above the projection and the flashing where the assembly meets the existing wall. Our installation includes proper flashing, weather seals, and (where needed) a small sloped cap roof that sheds water away from the assembly. A poorly installed bay or bow can leak; a properly installed one performs as well as flat windows for decades.

Can I put a window seat under a bay or bow window?

Yes, this is one of the most common uses. The projection creates a small alcove that’s the right size for a built-in bench, often with storage underneath. We can coordinate with your contractor or carpenter on the interior buildout, or recommend partners we work with in the Puget Sound area.

Are bay and bow windows energy-efficient?

Modern bay and bow assemblies with Low-E glass are as energy-efficient as their constituent windows, since each individual unit is a fully sealed modern window. The exception is the area beneath the projection (the cantilever) which needs proper insulation. Our installations include insulating the cantilever floor and ceiling, so the whole assembly performs like a normal exterior wall section.

Planning a bay or bow window for your home?

Free in-home consultation. No-pressure estimate. We’ll discuss configuration options, structural considerations, and timing for your project.

★★★★★

From the estimate process to the job itself, all excellent. Ken was personable and very efficient in measure and telling us what to expect. The crew was obviously very experienced, doing 7 windows in a little over half a day. Our only prep was moving furniture; we had no post job things to do at all - the crew cleaned up everything. This was a great experience. I will admit that based on good recommendations on the Fircrest 411 site, I did not even get a second bid, so can't comment in detail on the value; I do think what we paid was in the ballpark. It's so nice when a contractor job goes so well from beginning to end; this is not always the case. I highly recommend SRC.

This company had excellent reviews and my experience was 5 star worthy. I appreciated the knowledge of the sales staff and how they respected where we were at in our buying process. We had educated ourselves and this was not our first bid. We were familiar with the product and wanted to get to pricing, which they did for us (I do not recommend if you are still learning about windows). We found the company to be responsive, professional and such a pleasure to work with from sales, installers to the business office personnel. We had one window that came scratched that the installers caught and placed a claim into Milgard for replacement which happened promptly. We are so happy with our Milgard windows and the pricing we got. You can't go wrong with SRC Windows if they have what you are looking for. I would recommend them to a friend and would use them again without hesitation.

SRC Windows and Doors is hands down one of the best suppliers I’ve worked with. I’ve used them on many jobs and they are ALWAYS reliable and ALWAYS on time. The staff is friendly, knowledgeable, and genuinely helpful—they make the whole process easy from start to finish.
Quality products, great communication, and people who actually care—can’t ask for more than that. I’ll continue using them for all my window and door needs and would recommend them 100% without hesitation.

Before and after, please excuse the clutter we are still renovating! The crew were very friendly and quick! They laid tarps to catch and screws or old calking. They left no mess! I would absolutely recommend SRC windows!!

We are a developer and remodeling contractor who knows a ton about buying windows! SRC Windows is amazing. Their customer service is outstanding to say the least. They make the ordering process simple and are very accommodating to any needs that are requested. Tess the owner goes above and beyond and gets the job done. Thank you SRC, we all greatly appreciate your team here at Pacific Coast.