Curtain wall system

Explore TECHNAL's curtain wall system designed for commercial and public buildings. Secure, durable, and made from Hydro CIRCAL® recycled aluminium.

TECHNAL's curtain wall system forms part of its range of aluminium façade systems for commercial buildings. Discover a lightweight, non-structural facade system that combines performance with architectural flexibility. Designed to resist wind and weather, aluminium curtain wall systems support glazed or opaque infill panels while transferring imposed loads safely back to the primary building structure.

What Is a Curtain Wall System?

A curtain wall system is a non-load-bearing external building envelope that is fixed back to a building's primary structure. Unlike structural walls, curtain walling systems do not support the weight of the building. They are designed to resist external forces while supporting infill panels. Most curtain wall systems consist of vertical mullions and transoms that form a structural grid, into which glazing or other facade panels are installed. This provides architects with a flexible façade solution that can be tailored to a project's aesthetic and performance requirements. Glazed curtain walling systems are typically used across:

Commercial offices.
Healthcare buildings.
Education projects.
Hotels.
Mixed-use developments.
Residential developments.

By combining architectural flexibility with high levels of façade performance, curtain wall systems have become a common choice for modern buildings throughout the UK and Ireland.

How Curtain Walling Works in Commercial Façade Construction

In curtain walling construction, vertical mullions and horizontal transoms are fixed to the building structure to create a structural grid. Glazed or opaque infill panels are then installed within this framework to form the external facade.

Although the facade is non-load-bearing, it transfers wind and other imposed loads back to the floor slabs or structural frame through its fixing system.

Integrated drainage paths help manage rainwater, while gaskets and seals improve air and weather resistance. Movement joints are also incorporated to accommodate thermal expansion, contraction and slab deflection throughout the building's lifecycle.

Understanding these aluminium curtain wall details during the design stage helps ensure curtain walling systems integrate effectively with the wider building envelope, reducing specification risks and supporting long-term facade performance.

Curtain Wall System Types and Design Options

The choice of curtain wall system types vary depending on the project's design, construction programme, installation strategy and performance requirements. The two most common approaches are stick curtain wall systems and unitised curtain walling, each offering different advantages depending on the building and delivery method.

Other design options may include capped or structurally glazed appearances, pressure-equalised systems and integrated opening vents to support natural ventilation, smoke control or maintenance access where required.

Stick Curtain Wall System

A stick curtain wall system is assembled on site using individual aluminium mullions, transoms and glazing units. This approach offers flexibility during installation and is well suited to projects with complex façade geometry, phased construction programmes or varying floor layouts.

As components are installed individually, aluminium curtain walling fabrication and site coordination play an important role in achieving the required performance, tolerances and finish. Stick systems are commonly specified for bespoke commercial developments and refurbishment projects where flexibility is a priority

Unitised Curtain Walling

Unitised curtain walling systems are manufactured as factory-assembled modules before being transported to site for installation. This approach can improve installation speed, quality control and programme certainty, making it particularly suitable for larger commercial buildings with repetitive façade layouts.

However, unitised systems may be less appropriate for smaller or highly bespoke projects where increased design flexibility and on-site adaptation are required. Careful curtain wall manufacturing coordination is essential to ensure modules integrate successfully with the building structure.

Unitised curtain walling is available from our sister company WICONA.

Curtain Wall System vs Window Wall System

Though there are similarities, a curtain wall system and a window wall system serve different purposes within the building envelope.

A curtain wall system is installed externally and typically spans across floor slabs, transferring wind and environmental loads back to the primary building structure. This makes it well suited to larger commercial buildings where façade performance, architectural flexibility and continuous external glazing are key design considerations.

By comparison, commercial window systems are typically installed between floor slabs, with each window serving an individual floor level. Window wall systems can provide an effective solution for many residential and mixed-use developments but generally offer less design flexibility than curtain walling for large-scale commercial façades.

Selecting between curtain wall window systems depends on the building's structural design, performance requirements and architectural objectives.

Performance, Compliance and Sustainability Considerations for Curtain Wall Systems

Specifying a curtain wall system for a UK commercial project requires an understanding of the overall performance of the facade rather than focusing on a single criterion. Key specification considerations include:

Thermal performance.
Air permeability and watertightness.
Wind resistance.
Acoustic performance.
Movement tolerance.
Durability and maintenance.
Embodied carbon and recyclability.
Compatibility with Net Zero objectives.

Performance should be assessed alongside the relevant UK Building Regulations and Approved Documents, taking into account the specific requirements of the building, its location and intended use.

Thermal Performance, Part L and Net Zero

Thermal performance should be considered early in the specification process, as it plays an important role in the overall efficiency of the building envelope. When assessing an aluminium curtain wall system, project teams should review:

U-values.
Thermal breaks.
Glazing specification.
Solar control.
Airtightness.
Potential risk of overheating.

These factors influence operational energy demand and can help support compliance with Part L of the Building Regulations, depending on the system configuration and project detailing.

For high-performance buildings, such as those targeting Passivhaus standards, curtain walling should be specified as part of the wider facade strategy to ensure it integrates effectively with the building envelope and overall energy performance.

Curtain Wall System Specification, Fabrication and Installation Considerations

Successful curtain walling construction begins with careful planning during the specification stage. Before selecting a system, project teams should consider:

Grid dimensions and spans.
Mullion depth.
Glazing loads.
Fixing strategy and tolerances.
Drainage and water management.
Slab edge interfaces.
Integration with doors and windows.
Site access and installation sequencing.
Long-term maintenance requirements.

Considering these aluminium curtain wall details early helps improve coordination between design, curtain wall manufacturing, fabrication and installation. This collaboration reduces project risk and supports long-term facade performance.

Common Curtain Wall Design Challenges: How to Reduce Risk

Early technical coordination can help reduce many of the risks associated with curtain wall systems. Common design challenges include:

Water ingress.
Condensation.
Thermal bridging.
Movement failure.
Poor interface detailing.
Inadequate drainage.
Seal degradation.
Acoustic underperformance.
Glass replacement access.
Coordination between the façade, structure and internal partitions.

TECHNAL supports project teams with specification advice, detail reviews and fabrication coordination to help identify potential issues early. Contact our team to discuss your façade specification.

Cost Factors for Curtain Wall Systems

The cost of a curtain wall system depends on the specific requirements of each project. Factors that influence cost include:

Facade size.
System type.
Glazing specification.
Performance requirements.
Building height.
Site access.
Installation complexity.
Acoustic requirements.
Bespoke detailing.
Project location and programme.

For accurate pricing, it is recommended that project teams discuss their requirements with a specialist supplier at the early specification stage.

Technical Resources for Curtain Wall Specification

TECHNAL provides a range of technical resources to support curtain wall specification, including:

Product documentation.
Curtain wall system PDF downloads.
Revit and BIM objects.
CAD details.
Performance certifications.
Environmental documentation, where available.
Training and technical support.
Façade specification guidance.

Speak to TECHNAL about your facade specification.

Choosing a Curtain Wall System Supplier for UK & Ireland Commercial Projects

Selecting the right supplier is as important as selecting the right curtain wall system. When comparing curtain wall manufacturers, curtain wall suppliers and curtain wall companies UK, consider: