Why Structural Glazing Is the Preferred Choice for Commercial Buildings
Structural glazing is the reason commercial buildings can now wear a facade with almost no visible metal. The glass bonds straight to the frame with silicone sealant or hidden fittings.
As a manufacturer that fabricates curtain wall and glazing systems for commercial projects. We get asked on almost every call why architects keep specifying structural glazing over a standard framed system.
This guide walks through the materials, the system types, and the performance numbers behind that choice. Plus a straight answer on where structural glazing falls short.
Quick Summary: Structural Glazing at a Glance
| Question | Short Answer |
|---|---|
| Why is structural glazing preferred over framed systems? | It gives a near-frameless look with more daylight and less thermal bridging |
| Most frameless option? | Four-sided structural glazing |
| Most budget-friendly option? | Two-sided structural glazing |
| Best for maximum transparency? | Point-supported (spider) glazing |
| Fastest to install? | Unitized structural glazing (factory pre-glazed) |
| Typical sealant lifespan? | 20 to 25 years before inspection or replacement |
What Is Structural Glazing?
Structural glazing fixes glass panels to a building’s structural frame with high-strength silicone sealant or concealed mechanical fittings. So no aluminium cap is ever visible from outside. The glass sits almost flush against the building’s face. This is why a facade reads as one continuous sheet of glass from the street.
The glass panel is not what holds the building up. It passes wind pressure, thermal movement, and its own weight back to a hidden aluminium or steel sub-frame sitting behind it. The sub-frame carries the structural load; the glazing just has to stay sealed and firmly attached.
Our point-supported and framed glass curtain wall systems both use structural glazing principles. They are engineered and fabricated at our Foshan factory before shipping.
Why Architects Choose Structural Glazing for Commercial Buildings
Architects specify these mainly because of the clean, frameless look and the extra daylight it brings into the interior.
- Frameless appearance. No caps or pressure plates interrupting the glass line
- More daylight. Less metal on the facade opens up more usable glass area
- Reduced thermal bridging. Less exposed metal on the exterior limits unwanted heat transfer
- Design freedom. Large, uninterrupted glass spans give architects room for bolder building forms
Good looks alone don’t make a facade work. It only performs as well as its sealant, its sub-frame, and the crew installing it. This is exactly why it pays to source all three from one factory instead of splitting the job across vendors.
Types of Structural Glazing Systems
Two-sided, four-sided, point-supported, and unitized are the four main types used on commercial buildings today.
1. Two-Sided
Two-sided systems bond the glass with silicone on two opposite edges, usually top and bottom. While the other two edges sit in a conventional frame. This gives a partially frameless look at a lower cost than a full four-sided system.
2. Four-Sided
Four-sided structural glazing bonds all four edges of the glass panel with structural silicone. Thus, leaving no visible frame from the outside.
This is the system most people picture when they hear the term structural glazing, and it delivers the most seamless finish.
3. Point-Supported (Spider) Glazing
Point-supported glazing holds each glass panel with countersunk stainless steel fittings at the corners instead of continuous sealant lines. They are often paired with steel spider brackets.
It is common on lobbies, entrances, and feature walls where maximum transparency matters most. And it is one of the curtain wall styles we fabricate for hotel and commercial entrances.
4. Unitized
Unitized systems are pre-glazed and sealed at the factory, then shipped as complete panels and craned into place on site. This cuts weather-dependent, on-site wet-sealing work and speeds up installation on tall buildings.
Materials Used in Structural Glazing
Glass, aluminium framing, and structural silicone sealant are the three core materials that make a structural glazing system work.
1. Glass Types
Toughened (tempered) glass, laminated glass, and insulated glass units (IGUs) are all used in structural glazing. They are chosen based on safety codes, climate, and the building’s energy targets.
Laminated glass is often required on overhead or point-supported applications for fall-safety reasons.
2. Aluminium Framing
Even in a frameless-looking facade, an aluminium sub-frame sits behind the glass to carry structural loads. Thermally broken aluminium, like the profiles used in our aluminium window range, is standard here. Because it resists corrosion and limits heat transfer through the hidden frame.
3. Structural Silicone Sealants
Structural silicone is the adhesive that actually holds the glass to the frame in two- and four-sided systems.
It has to resist UV exposure, temperature swings, and constant wind load without losing adhesion for the life of the facade.
Structural Glazing vs Traditional Curtain Wall
The table below compares structural glazing against a traditional framed curtain wall on the factors that matter most to a commercial project.
| Factor | Structural Glazing | Traditional Curtain Wall |
|---|---|---|
| Visible framing | Minimal to none | Visible aluminium caps |
| Daylight area | Higher | Moderate |
| Thermal bridging | Lower | Higher |
| Upfront cost | Higher | Lower |
| Installation skill needed | High | Moderate |
| Best for | Feature facades, entrances, high-rises | Large-scale, budget-driven projects |
Performance Factors That Matter Most
Wind load capacity, thermal performance, water and air infiltration control, and sealant lifespan. These are the four performance factors that decide whether a structural glazing facade lasts.
1. Wind and Structural Load
Structural glazing has to pass structural load testing under standards such as ASTM E330 for wind and static load resistance. This confirms the sealant and sub-frame together can hold the glass under design wind pressure without failure.
2. Thermal Performance
Because there is less exposed metal, structural glazing generally performs better on thermal bridging than a capped curtain wall. Though the glass specification still drives most of the result.
IGUs with low-E coatings help structural glazing meet ENERGY STAR and similar efficiency targets on commercial projects.
3. Water and Air Infiltration
Every joint in a structural glazing system is a potential leak point. So systems are tested against AAMA water penetration and air leakage standards before approval.
Factory-glazed unitized panels generally perform better here than site-sealed stick systems. Since the critical seals are made under controlled conditions.
4. Sealant Lifespan and Maintenance
Structural silicone typically lasts 20 to 25 years before it needs inspection or replacement. All depending on climate and UV exposure.
Regular sealant checks are a standard part of any structural glazing maintenance plan. Not an optional extra.
How Structural Glazing Is Installed (Step-by-Step)
Structural glazing installation follows four main stages. From sub-frame anchoring to final sealant cure, whether the system is stick-built or unitized.
- Step 1. Anchor the aluminium or steel sub-frame to the building’s structural slab or columns
- Step 2. Set the glass panels into the frame using setting blocks for even load distribution
- Step 3. Apply structural silicone along the bond lines, either in the factory (unitized) or on site (stick-built)
- Step 4. Allow full sealant cure time, then carry out water and air infiltration testing before sign-off
We handle this process end to end through our design and installation guidance services. So the same team that engineers the panel also supports the crew putting it up.
Why Choose Starveil for Your Projects
Starveil is a strong fit for a structural glazing project because we engineer, fabricate, and support installation of the full curtain wall system from one Foshan factory.
- 28 years of experience and 1,500+ completed projects
- In-house design, aluminium fabrication, glazing, and on-site installation guidance
- ISO 9001 and SGS certified production, with certifications matched to each region’s building code
- Free drawings and 3D renderings before production
See completed facade projects on our about page, or contact our team for a structural glazing quote specific to your building.
Get Your Quote Today
Structural glazing only delivers on its promise when the sealant, sub-frame, and glass all come from a supplier who engineers them together. And that is the standard we hold every project to.
Send us your project drawings or floor plan, and our team will send a quotation within 24 hours. Get a free quote and let Starveil’s engineers design the right structural glazing system for your building.
FAQs
What is meant by structural glazing?
Structural glazing means fixing glass panels to a building’s frame using structural silicone sealant or hidden mechanical fittings instead of visible aluminium caps.
What are the types of glazing?
The main types of glazing used on buildings include single glazing, double glazing, triple glazing, laminated glazing, toughened glazing, and structural glazing.
What is 4-sided glazing?
Four-sided structural glazing bonds all four edges of a glass panel to the sub-frame with structural silicone. Leaving no visible metal frame on any side and giving the most frameless appearance.
What are the disadvantages of structural glazing?
The main disadvantages of structural glazing are higher upfront cost, dependence on skilled installation crews, and more complex repairs compared with a standard framed system.
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