Window Grills Explained: Between-Glass, SDL, and What Works in Canadian Homes

I get asked about window grills more than most people expect. Homeowners usually notice them when they are shopping for replacements and suddenly realize there are a lot of options, and that the choice is mostly permanent once the window is manufactured.

The main thing is understanding what each type actually means before committing.

The Three Main Types

Most Canadian window manufacturers offer three common grill configurations.

Between-glass grills are sealed inside the insulated glass unit itself. They sit between the panes, protected from weather, dust, and handling. These are one of the most common choices I see in new construction and replacement projects because they look clean, require almost no maintenance, and usually do not meaningfully change the certified performance of the full window unit.

SDL, or Simulated Divided Light, grills are applied to both the interior and exterior glass surface, usually with a spacer bar inside the unit to create the appearance of true individual panes. They give the most authentic heritage look, which is why they are popular in older homes where the original windows had real divided lites. The trade-off is that the exterior bars collect dirt, debris, and moisture, so cleaning takes more effort.

Removable interior grills are wood or plastic profiles placed on the inside of the sash. They offer flexibility because they can be taken off for cleaning, but they tend to collect dust, are limited in design variety, and can feel less refined compared to the other options.

How Climate Affects the Choice

Canadian winters are hard on anything exposed to the outside. Freeze-thaw cycles, ice buildup, and prolonged cold can affect exterior-mounted components over time.

SDL grills face that exposure directly. Paint can chip, frost can accumulate around the bars, and moisture can work its way into areas that are difficult to maintain in winter. Between-glass grills avoid most of that exposure because they are sealed inside the unit.

For homeowners who want to avoid seasonal maintenance headaches, between-glass is usually the more practical choice. For homeowners restoring or replacing heritage-style windows where authenticity matters, SDL may still be worth the trade-off.

Energy Performance and What to Watch For

A common question I hear is whether window grills make windows less efficient. The short answer is usually no, as long as the full window unit is properly built, rated, and installed.

Between-glass grills sit inside the sealed glass unit, so in most cases they do not meaningfully change the window’s insulation rating. If the full window unit is ENERGY STAR certified, the rating of the complete unit matters more than the presence of decorative between-glass grills.

For Canadian homeowners, NRCan’s key features and buyer tips for windows, doors, and skylights are useful for understanding which specs to verify before buying.

Where issues can arise is with SDL or surface-applied grills that use poor adhesive attachment. Over time, a compromised exterior attachment can create weak points or maintenance problems. This is another reason installation quality matters alongside product selection.

Matching Style to Your Home

Grill pattern is where homeowners sometimes get tripped up. Not every pattern suits every house.

Colonial and Prairie patterns are among the most commonly requested across Canadian homes. Colonial works well on traditional and symmetrical facades. Prairie, with its border grid pattern, suits craftsman and arts-and-crafts styles. Georgian and Ladder patterns have their own applications depending on the period and architecture.

Picking a grill pattern that clashes with the home’s style affects curb appeal and can be difficult to undo. If you are replacing windows in an older home, it is worth looking at photos of similar builds to see what pattern fits naturally.

Grill colour matching to the frame is another detail that gets overlooked. Most manufacturers offer white, sandstone, cream, and metallic finishes. A mismatched grill and frame colour is hard to correct after the fact.

If you are comparing grill layouts as part of a larger replacement project, AlphaTech’s custom window options can help you plan what belongs on the front, sides, and rear of the home.

A Quick Field Example

I worked with a homeowner replacing windows in a 1940s-era house. They wanted to replicate the original look of small individual panes without paying for true divided light.

We went with SDL grills in a Colonial pattern on the front-facing windows and between-glass grills on the sides and rear. That gave them the heritage curb appeal they wanted while keeping the maintenance burden manageable on windows they would rarely need to access closely.

That is also where overspending can sneak in. SDL may make sense on the front of a home, but it is not always worth paying for it on every window if those units are barely visible from the street.

Timing and Planning

Grills are selected at the manufacturing stage. They are factory-integrated, which means changing the grill style after installation usually requires replacing the full window unit.

Spring and early summer get busy quickly in the renovation season. If you have a specific grill configuration in mind, especially SDL or a less common pattern, ordering earlier can help avoid delays heading into fall.

The best choice is not always the most expensive one. In many homes, a clean between-glass grill gives the right look with less maintenance. In others, especially homes with a strong traditional style, SDL on selected elevations may be worth the added care.

Closing Thought

Grill choice is mostly a visual and maintenance decision. Get the type right for your climate and lifestyle, match the pattern to your home’s character, and coordinate the colour with your frames. Those three steps cover most of what goes wrong when homeowners look back and wish they had chosen differently.

Q&A

Will grills affect my window’s energy rating?

Between-glass grills usually do not meaningfully affect the certified performance of the full window unit. The important thing is to compare the actual window rating, not just the appearance package.

Can I change my grill style after installation?

Not easily. Between-glass and SDL grills are factory-selected and are usually permanent. Removable interior grills offer more flexibility, but they have fewer design options.

Do SDL grills cause problems in winter?

They can require more maintenance over time. The exterior bars are exposed to freeze-thaw cycles, frost, and moisture, so they need more cleaning and inspection than between-glass options.

Which grill pattern suits a heritage home?

Colonial and SDL configurations are common choices for older homes. Matching the pattern to the original window style usually gives the most natural result.