A common misconception about commercial windows: They’re the same – albeit slightly larger than residential windows. In other words, commercial and residential windows should be priced about the same, right?

That couldn’t be further from the truth. In actuality, commercial windows have a lot of differences compared to residential windows, and those differences have a significant impact on pricing.

Commercial windows, for example, are required to have higher wind ratings. They’re designed to bear greater structural loads, are more complex to install, and they typically require special coatings and glazing to ensure thermal performance in large office buildings, restaurants, and commercial properties.

Bottom line: Comparing residential windows to commercial windows would be a lot like comparing a Honda Accord to a bulldozer. Here’s a look at the differences between commercial and residential windows, and how those differences affect pricing.

How Commercial Window Installations Affect Cost

Commercial window installations are often complicated. They’re more challenging to plan for and more time- and cost-consuming to execute. In fact, the complexity of commercial window replacements adds to costs in three ways:

  • Equipment: A commercial property – particular mid- and high-rise properties – requires special equipment to hoist and place windows.
  • Customization: Most commercial windows are large and custom-built, and they typically require on-site glazing. Customization has a significant impact on cost.
  • Time: Due to installation complexity and that commercial projects tend to require more windows, commercial installations take longer to complete. This adds to greater labor costs.

Residential window options, on the other hand, tend to be available in standard sizes, which can help reduce customization costs. They’re also typically installed on one- or two-story properties, and this helps to limit installation costs.

Commercial vs Residential Windows: Design Requirements

The North American Fenestration Standard (NAFS) is a set of standards that regulate the performance of windows and doors in commercial construction. Windows, therefore, must be manufactured within the NAFS guidelines for the property to meet building codes.

There are several Performance Class ratings for windows, including Residential (R), Light Commercial (LC), CW and AW, and these ratings generally represent the type of application they’re rated for. Windows rated LC, for example, tend to be installed in low-rise commercial properties, while AW windows are common on high rises.

These ratings also relate to performance in a number of ways. With each level up in class, the window must meet successively higher minimum requirements in three areas:

  • Structural loads: Commercial windows generally bear greater structural loads compared to residential windows. Windows in high-rise properties, for example, must carry a significant load, and therefore, they’re typically classified as AW (which has the highest minimum load requirement).
  • Wind Resistance: Commercial windows are generally more resistant to high-speed windows. LC class windows, for instance, must withstand 99 MPH winds at a minimum, while residential windows are only required to withstand 77 MPH winds at a minimum.  
  • Water Penetration Resistance: Commercial windows are also generally more resistant to wind-driven rainwater. This is important since commercial properties tend to incorporate more windows in their exterior walls.

So how does this relate to costs? Windows that can bear greater structural loads and are more resistant to wind and water require more parts and materials. In other words, commercial-rated windows are more costly to manufacture – which is a primary reason for the cost differential.

Commercial Windows and Solar Heat Gain

Finally, commercial windows must be designed to limit the amount of solar heat that enters a property. Think about it like this: Commercial buildings generate a lot of interior heat – from crowds, lighting, computers and electrical outlets – and as such, commercial buildings require year-round cooling to counteract this created heat.

Sunlight that enters a property contributes to created heat, and if not correctly counteracted, it can cause many issues (from overheating to uneven temperatures.)

Residential properties, on the other hand, rely on sunlight for eating, and they are not crowded or create a lot of interior heat.

What does this have to do with window design? Commercial windows typically require special coatings, high-performance glazing and other measures to limit the amount of solar radiation that enters the property. This added feature increases manufacturing and materials costs – another contributor to the price differential.

Pricing Commercial Window Replacement and Installation Projects

The costs of a commercial window installation project can vary greatly. Windows may require custom manufacturing – to fit the particular project – and the installation itself may have some variables, including the number of windows, the complexity of installing the windows, and the size of the building.

In other words, it’s difficult – if not impossible – to estimate the costs of a project without talking with a commercial window installation company. The right partner can help walk you through window pricing, determine timeframes, and help you more accurately estimate labor and installation costs.

So before you start looking at the costs of a residential installer, save yourself some time and contact a commercial window installer.