The terms curtain wall and glass façade are often used interchangeably. Technically, however, they do not mean exactly the same thing. A glass façade primarily describes how a façade looks and which material defines its appearance. A curtain wall is a specific, non-loadbearing façade structure fixed to the primary structure in front of or between the floor slab edges. A curtain wall can consist largely of glass and therefore also be a glass façade, but not every glass façade is automatically a curtain wall.
If you are considering a curtain wall or glass façade it is therefore advisable to establish the intended appearance, façade build-up and technical requirements first. The name alone does not specify which profiles, glazing, fixings and junction details are needed.
What is a curtain wall?
A curtain wall is a lightweight external envelope that does not support floors or the roof. The system does support its own weight and transfers loads, such as wind loads, to the primary structure through anchors. The precise calculations and detailing form part of the design for the building concerned.
Many curtain walls consist of aluminium mullions and transoms with insulating glass units, opaque panels or a combination of the two between them. The vertical mullions and horizontal transoms form a recognisable grid. Depending on the chosen system, cover caps remain visible or the glazing has a flatter external appearance. Opening sections, doors and junctions with other façade elements can be incorporated into the design.
On the page about curtain walls you can read more about this specific façade solution. For the wider range of installation services, see façade systems.
What is meant by a glass façade?
Glass façade is a broader, visual description. It refers to a façade in which glass defines much of the appearance. The underlying structure may be a curtain wall or another system. Examples include large areas of framed glazing, linked glazed screens, storey-height glass elements or a structure with point fixings.
The term therefore says little about how the façade is supported, fixed and sealed. Two buildings may both have transparent glass façades while their structural arrangements differ considerably. For a quotation or technical discussion, the description ‘glass façade’ alone is therefore usually insufficient. Drawings, dimensions, the choice of system and glazing specifications provide the necessary clarity.
Curtain walls and glass façades compared
| Aspect | Curtain wall | Glass façade |
|---|---|---|
| Meaning | A specific type of façade with a non-loadbearing external envelope. | A broad description of a façade whose appearance is defined by glass. |
| Structure | Fixed to the primary structure and does not support floors or the roof. | Depends on the system used; this may be a curtain wall or another construction. |
| Materials | Often aluminium mullions and transoms with glass and, where applicable, opaque panels. | Predominantly visible glass, combined with profiles, window frames or other fixings. |
| Façade appearance | A regular grid of profiles and glazing, with visible or partly concealed cover caps. | Can range from clearly defined framed sections to glazing with as flush an appearance as possible. |
| Specification | The chosen system determines dimensions, detailing and installation sequence. | The term alone is insufficient to specify the technical construction. |
Which solution suits your project?
The choice starts with the design rather than the name. If you want a regular grid across several storeys, a curtain wall may be a logical solution. For a single transparent glazed screen or a series of large areas of framed glazing, another type of glass façade may be more suitable. The existing supporting structure, access and sequence of work also affect the feasibility of installation.
Appearance and panel layout
Decide how much of the framing you want to see in the façade and how the vertical and horizontal lines should align with floors, walls and façade openings. The positions of doors and opening sections also need attention. A balanced overall appearance relies above all on consistent dimensions and well-coordinated junctions.
Performance depends on the complete system
Thermal insulation, solar shading, airtightness, watertightness, sound insulation and fire safety are not inherent in the terms curtain wall or glass façade. They depend on the profiles, glazing, gaskets, joints, anchors and connections to the rest of the building. The required performance should therefore be specified for each project and technically assessed.
Installation and junction details
Installation brings design and site conditions together. Dimensional variations in the structural shell, anchor positions, glass weights and access to the façade influence planning. Details at roof edges, floors, corners, sills and adjacent masonry or sheet metal must also be clear in advance. View the how ACS Montage works for the steps from preparation to finishing.
Practical checklist for your façade project
The following information helps a façade specialist define the scope of your enquiry:
- Façade elevations, sections and relevant detail drawings.
- Overall dimensions, grid layout and preferred profile widths.
- Preference for a particular façade system, if one has already been specified.
- Type of glazing and any solid panels or spandrels.
- Position and opening direction of doors, windows and other opening elements.
- Requirements for thermal and acoustic performance, watertightness, airtightness and fire safety.
- Information on the substrate, supporting structure and fixing points.
- Access, lifting options, scaffolding and construction sequence.
- Junctions with the roof, floor, window frames and other façade cladding.
- Preferred finish, colour and visible detailing.
Photographs of completed installation work can help you assess the profile layout and standard of finish. To see examples, view the projects.
Frequently asked questions
Is every curtain wall a glass façade?
No. Many curtain walls contain large areas of glass, but a curtain wall can also include solid panels. ‘Glass façade’ mainly describes the appearance; ‘curtain wall’ describes the structural arrangement.
Is a curtain wall load-bearing?
A curtain wall does not support floors or the roof. It does, however, support its own weight and must resist loads and transfer them to the main structure through fixings designed for that purpose.
Can a curtain wall include windows and doors?
Yes, opening windows and doors can form part of the façade design, provided the chosen system and detailing are suitable. Their position, dimensions and junction details are specified in advance.
What information is needed for an initial assessment?
A floor plan or façade elevation, approximate dimensions, photographs of the site and a description of the desired appearance provide a useful starting point. System information, performance requirements and junction details are needed as the design develops.
Have your façade plans assessed
Are you deciding between a curtain wall and another type of glass façade, or has the system already been specified and you need an installer? Send drawings, dimensions and access information via the contact page. This allows ACS Montage to assess whether the installation work falls within its range of services.