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Understanding the Different Types of Curtain Wall Systems
More Than Just Glass on a Building
When people look at a modern office tower, hotel, or commercial complex, what they often admire first is the facade – the sleek glass exterior that defines the building’s identity. Behind that visual appeal lies a carefully engineered system known as a curtain wall.
Curtain wall systems are not one-size-fits-all. Choosing the right type has a direct impact on cost, performance, installation speed, maintenance, and long-term value. This guide breaks down the different types of curtain wall systems, explains where each works best, and helps developers, architects, and consultants make informed decisions – especially in the context of Sri Lanka’s climate and construction environment.
What Is a Curtain Wall System?
A curtain wall is a non-structural outer envelope of a building, typically made of aluminium framing and glass. Unlike load-bearing walls, curtain walls transfer wind and gravity loads back to the main building structure while providing weather protection, insulation, and aesthetics.
Key functions include:
- Protecting the building from wind and rain
- Allowing natural daylight
- Enhancing thermal and acoustic performance
- Creating a modern architectural appearance
Why Curtain Wall Selection Matters
Choosing the wrong system can lead to:
- Water leakage during monsoons
- Excessive heat gain and higher cooling costs
- Difficult maintenance at height
- Delays during installation
Choosing the right system ensures:
- Faster construction timelines
- Better long-term performance
- Lower lifecycle costs
- Improved tenant and occupant comfort
The Main Types of Curtain Wall Systems
1. Stick System Curtain Walls
What it is:
The stick system is assembled piece by piece on-site, with vertical mullions and horizontal transoms installed first, followed by glazing.
Best suited for:
- Low- to mid-rise buildings
- Projects with tight budgets
- Sites with limited access for large prefabricated units
Pros and Cons
| Pros | Cons |
|---|---|
| Lower initial material cost | Slower installation |
| Flexible on-site adjustments | More labour-intensive |
| Ideal for simple geometries | Greater exposure to weather during install |
Stick systems are often chosen when budgets are tight, but timelines are flexible. However, in Colombo’s unpredictable weather, longer on-site exposure can increase risk.
2. Unitized Curtain Wall Systems
What it is:
Unitised systems are prefabricated in factory-controlled conditions, delivered to site as complete panels, and installed floor by floor.
Best suited for:
- High-rise buildings
- Commercial towers and hotels
- Projects with strict timelines
Key Advantages
| Feature | Benefit |
|---|---|
| Factory fabrication | Higher quality control |
| Faster installation | Reduced site disruption |
| Weather-tight units | Better performance in monsoon conditions |
3. Semi-Unitized Curtain Wall Systems
What it is:
A hybrid approach where some components are prefabricated while others are assembled on site.
Why choose it:
- Balance between cost and speed
- More flexibility than full unitized systems
- Suitable for medium-rise commercial buildings
This system is often selected when developers want better quality control than stick systems, without the full cost of unitized façades.
4. Structural Glazing Curtain Walls
What it is:
Structural glazing systems use silicone sealants and concealed framing, creating a seamless glass appearance with minimal visible aluminium.
Ideal for:
- Corporate headquarters
- Luxury hotels
- High-end commercial buildings
Visual & Performance Benefits
- Clean, uninterrupted glass façade
- Modern, premium aesthetic
- Improved daylight penetration
Important consideration:
Structural glazing requires precise engineering and expert installation. Poor detailing can lead to long-term maintenance issues.
5. Double-Skin Curtain Wall Systems
What it is:
A system with two layers of glazing, separated by a ventilated cavity that improves insulation and environmental control.
Why it matters in 2026:
- Supports energy-efficient and green buildings
- Reduces cooling loads
- Improves acoustic insulation
Curtain Wall Systems at a Glance
| System Type | Cost Level | Installation Speed | Performance | Best For |
|---|---|---|---|---|
| Stick | Low | Slow | Moderate | Low-rise buildings |
| Semi-Unitized | Medium | Medium | Good | Mid-rise offices |
| Unitized | High | Fast | Excellent | High-rise towers |
| Structural Glazing | Medium-High | Medium | High | Premium projects |
| Double-Skin | High | Medium | Very High | Sustainable buildings |
Choosing the Right System: Key Factors to Consider
When selecting a curtain wall system, consider:
- Building height and geometry
- Project timeline
- Budget and lifecycle costs
- Climate exposure (wind, rain, sun)
- Maintenance access and long-term upkeep
The “cheapest” option upfront is rarely the most economical over 20–30 years.
Why Curtain Walls Perform Well in Sri Lanka
Sri Lanka’s tropical climate demands systems that can handle:
High Humidity
Heavy Rainfall
Strong Solar Radiation
Aluminium-based curtain wall systems excel because they:
- Resist corrosion
- Support high-performance glazing
- Require minimal maintenance
- Adapt well to both coastal and urban conditions
Why Work with Unisyst for Curtain Wall Systems
At Unisyst PLC, curtain walls are not treated as off-the-shelf products. Each system is engineered based on project requirements, performance criteria, and site conditions.
What sets us apart:
- Backed by the Hayleys Group
- In-house technical and fabrication expertise
- Experience across commercial, hospitality, and high-rise projects
- End-to-end responsibility — from design to installation
The Right System Makes All the Difference
Curtain wall systems define how a building looks, performs, and ages. Understanding the differences between stick, unitised, structural glazing, and advanced systems empowers developers and consultants to make smarter, future-ready decisions.
With the right system — and the right partner — curtain walls become more than an architectural feature; they become a long-term asset.
Planning a new commercial or high-rise project?
Speak to Unisyst Engineering to explore the most suitable curtain wall system for your building.