Blog > Category > Posted: 2023-Nov-16, Updated: 2024-Mar-13

The ins and outs of window grills

The Ins and Outs of Window Grills
Windows are an essential part of any home, serving as a source of natural light, ventilation, and insulation. However, homeowners often struggle with choosing the right style and design that complements their home's aesthetic and functionality. One popular design choice that homeowners face is whether or not to add window grills.

Window grills, also known as muntins or grids, are decorative pieces that divide a window pane into smaller sections. They come in various shapes, sizes, and styles, and can be made from a variety of materials such as wood, aluminium, or vinyl. While grilles can add an element of style and charm to your home, they may not be suitable for every home and situation.

To help homeowners make an informed decision, Bayview Windows has put together a comprehensive guide on the ins and outs of window grills. Our guide explores the various types of window grills, their benefits and drawbacks, and how to choose the right style for your home. Whether you're looking for a traditional colonial style or a contemporary look, our guide will provide you with all the information you need to make the best decision for your home.

What is a window grill?

A window grill is a decorative grid pattern consisting of horizontal and/or vertical bars that divide a larger sheet of glass into smaller panes. Traditionally, a window grill, known historically as a muntin, muntin bar, sash bar, or grid was invented purely for ease of production and economical reasons. Smaller-sized pieces of glass were less expensive to manufacture, less likely to break, easier to manage and safer to ship than larger pieces of glass. As a result, gridded windows were invented and became the accepted style of window in many countries.

Grids can add that special touch to match a window or door to an architectural style, turning a large open pane into a dramatic statement. However, grids or grills as we will call them in this blog entry vary in pattern complexity and style which can be a consumer dilemma. This month's story was written to help the consumer understand what grill options are available and whether a grill is something that should be considered for their new or existing home.

Modern glass manufacturing brings new styling opportunities

With the advent of modern glass-making procedures, it has become easier for window manufacturers to produce larger, stronger, less delicate pieces of glass that can span an entire window frame and the development of multi-paned energy-efficient glass. So why grilled windows? The answer is purely aesthetics! The much-loved traditional gridded window of the past did not fade away, so window manufacturers find ways to appeal to their consumers. Thus, the invention of today’s window grills, available in all kinds of patterns, style types, profiles, thicknesses and materials.

An added bonus

Traditional window grids required the cleaning of each grid divider and glass pane individually. Today, a majority of multi-paned windows have grills that are sandwiched between the panes, keeping the grids free of dust and making window cleaning so much faster and easier. Along with the gridded window’s aesthetic appeal and design, it packs benefits capable of lowering a home’s solar heat gain coefficient.

Matching the style of your home

Grills are a great way to add style and elegance to your windows. And with today’s multiple window pane technologies, many manufacturers offer standard and custom configurations between the panes, and even simulated dividers on the exterior of the glass to provide a more traditional look.

As a homeowner, putting grills in your windows can make them look unique, however, when making a choice as to whether you should choose grills or not, you should first think of your home as falling into one of three categories: traditional, contemporary or modern.

Traditional homes

Traditional and colonial-styled Canadian homes are homes that were built up to and around the late ’80s. These homes typically had gridded windows with classical-style trim, porches, classical balusters and in keeping with the existing style of the home traditional gridded windows.

Contemporary homes

The term contemporary architecture is a standard phrase that essentially refers to the architecture of today. While there is no clear definition of what constitutes contemporary architecture, it comprises a range of building styles that often look very different from one another. Non-grilled windows are typically applied to contemporary homes to enhance lighting within and not obstruct views to the outside.

Modern homes

While grids are great for traditional homes, non-grid options are a good choice for modern home upgrades. Bungalows, Ranch-style homes and modern neighbourhood homes look great with clean, un-gridded window styles.

Other considerations

Of course, there are no rules as to whether you should grill or not grill your windows, however, there are some considerations that could be taken into account. For example: if the view out of a window is very boring, a grilled window may make the view out more interesting; grilled windows are typically applied to the front of a home, not the sides or the back of the home; sometimes the view out of a window is so extraordinary that it should not be obstructed by a grill or busy grill pattern.

Grill patterns

Many window manufacturers offer grill patterns to match your existing windows, of course, there are only a few patterns that are considered standard patterns with standard names. Window manufacturers will often create their own unique grid names to separate them from the competition, so be sure to look at the patterns carefully.

The most popular style of window grill layouts is Prairie and Colonial style. Colonial-styled grills are great for making tall, narrow windows look wider. Prairie grills can frame a large window nicely, making it more interesting.

Common Grill Patterns:

Standard Grill Patterns

Grill types

Grills (grids) between the glass (GBG)

The most common grill option, these grid dividing systems sections are sandwiched between glass panes in dual and triple-glazed windows. They are easy to clean and can be colour matched to the colour of the window frame.

Simulated divided lites (SDL)

Simulated divided lites are grids bonded to the window’s interior and exterior to give a window an old wooden separated windowpane traditional look. SDL creates the impression of true divided lites and brings heritage styling to traditional, contemporary and modern homes. For an even more authentic look, custom-fitted grills between the glass are offered as an option by most window companies (between the panes/exterior SDI, or true divided lites (TDL)).

Detachable removable grills

Detachable grids are a great option offered by some window manufacturers, although not typically available in the Ottawa area, these can be custom-made to fit existing windows and can be applied or removed as the homeowner desires.

Grill sizes, profiles & colours

Grill Types


Windows manufacturers don’t make it easy for customers when it comes to picking grill widths - sizes often differ from one manufacturer to another. Architects will tell you that you need a certain thickness for a certain window dimension based on whether it is horizontal or vertical. The main goal for many manufacturers is to be able to match windows that you already have in your home, whether you are replacing one window or all your windows. They usually range from as narrow as 1/4 in. for circular to 1 3/8 in. for flat grills.


Grills can be rectangular, circular, flat, or have a protruding edge, and they can be combined to create a certain look that could perhaps suggest a hung or sliding window.


Most window manufacturers offer colour windows and colour grills in various sizes to match the window colour.

Grill materials

Grills can be manufactured in a variety of metallic and vinyl materials to match your existing windows and help you create a perfect custom style that suits your home or your taste.

Grills & energy efficiency

Because grills take up space inside an insulated glass unit, they reduce the amount of sun that warms your home. They also allow for less gas fill to be inserted into the sealed unit, thus making it more susceptible to heat loss than regular non-grilled windows. Unfortunately, this means grills will make your window less energy efficient than the same window without grills.

Broken grills

One of the biggest post-installation problems associated with grills is that over time, they can fall out of place. Unfortunately, there is no easy fix for fallen window grills and the only way to resolve the problem is by replacing the entire sealed unit. If you are choosing grills as a window option, be sure to discuss the warranty and service procedures with your window consultant.

Talk to an expert

There’s a lot to think about when trying to match grills to already installed windows. Bayview Windows carries several different window brands, each with its own grill sizes, styles, patterns, materials and colour options to maximize your window choices.

Diagram - Anatomy of a window (interior view)

Infographic -
What's there to know about windows

Diagram - Anatomy of a window (exterior view)

e-book - Almost everything to know about windows

Choosing a window style - a practical guide

How to ensure a successful window purchase

Need more information?

If you would like more information or are not sure what grilling options are right for your home, talk to one of our window experts, we’d love to help.

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