No contractor has ever complained about too many details.
Even if you’re taking direction from an architect or engineer, knowing the specifics of facade systems can make big differences in project quality and cost. A prime example is curtain walls vs. storefronts – outside of allowing daylight and inside views, there’s surprisingly little overlap between these two systems.
Because it never hurts to know what you’re getting into, here are clear definitions and job-site concerns for both:
Storefront, curtain wall, veneer, facade – no matter the name, in the case of a commercial front, it’s almost always a glass-heavy design.
In construction, “curtain wall” refers to an exterior shell that acts as an extension of the building envelope. Unlike other parts of an envelope, it serves a unique purpose on a commercial building.
A curtain wall is nonstructural, instead serving as a protective and aesthetic feature. Because this facade type carries no structural load, the designer is free to experiment with materials. The most popular choices are lightweight materials, such as glass or aluminum (or both).
Important: A curtain wall includes, but isn’t limited to, the front “face” of a building.
|
Feature |
Storefront |
Curtain Wall |
|
Primary Material |
Extruded aluminum framing |
Extruded aluminum framing |
|
Sightline |
1.75 to 2” |
2 to 2.5” |
|
Depth |
4.5 to 6.5” |
6 to 10” |
|
Infill Options |
Primarily glass |
Can include glass, metal, or stone panels |
|
Glass Type |
1” insulated glass units (IGUs) |
Large, multipane IGUs |
|
Securing Method |
Glazing gaskets & snap-in stops; structural silicone (high-end systems) |
Pressure plates & caps; structural silicone (high-end systems) |
A storefront is the front veneer of a commercial structure. Storefront systems are simpler, nonstructural systems for livening up the ground level of a commercial or building.
There’s a heightened emphasis on curb appeal when it comes to front-facing exteriors. Visitor accessibility is also at the top of the priority list.
While there are always exceptions, the predominant dimensions for U.S. storefronts are what you see above. Basic dimensions are just one of several ways these facades differ from curtain walls.
Forget the initial similarities. There are different practices and pitfalls for speccing, engineering, manufacturing, and constructing storefronts and curtain walls (and window walls, for that matter).
You may not be using or paying for the final result – or even specifying its details – but it’s still valuable to understand all parties’ intentions.
Curtain walls have become a staple of big, multistory buildings and skyscrapers. They can cover large expanses with sleek, modern protection. Glass is usually the star of the show here, as many times it covers the building floor-to-ceiling.
Modern curtain wall systems focus on thermal efficiency (more on that in #4). Nonetheless, since they’re aesthetically pleasing, at ground level they can actually replace storefront systems. They’re great for buildings requiring extensive natural light and a variety of views.
Storefronts, unlike curtain walls, are generally limited to a single story or low-rise. At ground level, they can provide an inviting and visible path to a:
Easy pedestrian access and visual appeal are extra-important with store veneers.
You shouldn’t treat either facade type as a fully structural component. Still, there are shades of gray here.
Curtain walls do not bear roof or floor loads; instead, they’re attached to the building's frame. They get their name because the installer hangs them off the structure like a “curtain.”
These facades support their own weight – often large glass panels – via a grid of aluminum or steel. This requires a complex system of mullions and transoms to hold the weight of the glass and resist environmental forces. Glazing structural tape and metal panels bond and support these large panes.
Because they’re not on the hook for structural duty, curtain walls can be much larger than storefronts. A curtain wall frame can reach 13’ or higher.
Storefronts, usually anchored directly to the building’s foundation or an adjacent wall, offer a small amount of structural support at ground level. Using mullions and transoms, storefronts can carry some of the weight of the glass and frame, especially in low-rise applications. However, it’s not in their job description to handle heavy wind loads or structural shifts.
Unfortunately, the weight load a storefront has to carry limits its frame height to 10’. Thickness is also different from curtain walls, as the chart above shows.
Both storefronts and curtain walls can benefit from commercial-grade facade restoration products and techniques.
Curtain walls have a surprisingly valuable role – one that goes far beyond surface looks. Depending on the specific system, they can offer several benefits to a building envelope’s performance:
|
Benefit |
How It Happens |
|
Energy Efficiency |
• Insulated glass |
|
Water Resistance |
• Sealants |
|
Wind Protection |
• Flexible aluminum frame |
Generally speaking, curtain walls are better at withstanding severe conditions and stopping water ingress. The system weeps each piece of glass separately.
Storefronts put top priority on accessibility and visibility, which results in less design emphasis on weather resistance. Notably, they handle water differently than curtain walls do.
On a storefront, the entire elevation is weeped at the sill. The system directs incoming water down the vertical mullion to the sill and then weeps it outside the building.
This issue ties back into the height limitation of shopfronts. They belong no higher than the third floor of a building, and there should be an overhead roof section protecting it.
Storefront systems still require weatherproofing products, especially at ground level, where exposure to water and snow is higher. Paintable protection, such as polyurethane-silicone hybrid sealants, helps to close gaps and maintain a sleek appearance.
Curtain wall installation is a specialized process due to their size and how they integrate with a building’s structural system. Adding to the challenge is the need for precise installation and sealing so that components don’t falter in the face of wind loads.
Contractors also need to account for:
Construction specs most often call for structural tape, paintable sealants, and metal panels to support durability and energy efficiency.
Storefront installation is generally faster and more straightforward, as it involves less height and structural complexity.
Store facades also don’t need as much overall protection against wind or temperature changes. However, glazing tape and paintable sealants are still helpful for weatherproofing and ensuring a clean finish.
Expectations are different for full curtain walls vs. storefronts. So too are the costs.
No matter which kind of facade you choose, certain factors may influence the price:
As for system-specific costs?
Curtain walls are generally more expensive to install due to their size and the intensity of the labor involved. Their material makeup also contributes to a higher price point. In most large-scale construction, the superior performance is easily worth the up-front price.
Storefronts are cheaper to install, making them a more attractive option for small projects and lower elevations. You can always advocate for a storefront if savings are critical to the project, and the design doesn’t require a curtain wall’s scale or performance.
Comparing the features and differences of storefront and curtain wall systems is a smart move – the earlier in the project, the better. This ensures your construction looks great, withstands the elements, meets structural needs, and stays within budget.
In short, contractors should view curtain walls as complex, environment-resistant facades that need strong product support and careful installation. Storefronts are more straightforward, ground-level solutions focused on accessibility and aesthetics.
In certain projects, performance standards related to wind loads, energy efficiency, or even seismic resistance might dictate that you use curtain walls. No matter the decision, make sure your techniques and products match the performance needs of the building.
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