In this article, we’ll be examining the differences between stick curtain walling and unitised curtain walling. Both approaches have their advantages and disadvantages and it’s important to understand these differences in order to choose the best option for your building project. We’ll be looking at a range of factors, including costs, programme duration, cash flow considerations, maintenance, thermal performance, structural movement and installation methodology.
Stick Curtain Walling vs Unitised Curtain Walling
Overview
Stick curtain walling and unitised curtain walling are two popular approaches to installing glazing on a building facade.
Stick curtain walling involves assembling individual components (such as mullions and transoms) on site and then installing the glazing panels into these components.
Unitised curtain walling involves prefabricating larger sections of the curtain wall (known as “units”) off-site and then installing these pre-made units onto the building structure.
Cost Considerations
- Stick curtain walling is generally less expensive than unitised curtain walling, as it requires less specialized equipment and labour to assemble the components on site.
- Unitised curtain walling is more expensive due to the increased cost of prefabricating the units off-site, as well as the need for specialized transportation and lifting equipment to install the units on site.
Programme Duration Off Site
- Unitised curtain walling requires more time and planning off site, as the units must be fabricated and shipped to the site before installation can begin.
- Stick curtain walling can begin as soon as the components arrive on site, as the assembly and installation process can be done concurrently.
Programme Duration On Site
- Stick curtain walling requires more time on site, as each component must be assembled and installed individually.
- Unitised curtain walling can be installed much more quickly on site, as the pre-made units can be lifted into place and attached to the building structure.
Cash Flow Considerations
- Unitised curtain walling requires a greater upfront investment, as the units must be fabricated and paid for before installation can begin.
- Stick curtain walling allows for a more flexible payment schedule, as the components can be paid for as they are assembled and installed.
Maintenance
- Stick curtain walling is generally easier to maintain, as each component can be accessed and replaced individually if necessary.
- Unitised curtain walling can be more difficult to maintain, as the units are larger and more complex to disassemble and replace.
Thermal Performance
- Unitised curtain walling generally provides better thermal performance, as the pre-made units can be factory-sealed and insulated to a higher standard than the individual components used in stick curtain walling.
- Stick curtain walling can still achieve good thermal performance, but may require more attention to sealing and insulation during the assembly process.
Structural Movement
- Unitised curtain walling is better able to accommodate structural movement, as the pre-made units can be designed to flex and shift with the building structure.
- Stick curtain walling may require additional design considerations to accommodate structural movement, as the individual components are less flexible.
Installation Methodology
- Stick curtain walling requires skilled labour to assemble and install the components on site and may require scaffolding or other equipment to reach higher elevations.
- Unitised curtain walling requires specialized transportation and lifting equipment to install the pre-made units, but may require less skilled labour on site.
| Stick Curtain Walling | Unitised Curtain Walling | |
| Cost | Less expensive due to less specialized equipment and labour | More expensive due to prefabrication and specialized transportation/lifting equipment |
| Programme Duration Off Site | Can begin as soon as components arrive on site | Requires more time and planning off-site for fabrication and shipping |
| Programme Duration On Site | Requires more time on site as each component must be assembled and installed individually | Can be installed more quickly on site as pre-made units can be lifted into place |
| Cash Flow Considerations | Flexible payment schedule as components can be paid for as they are assembled and installed | Requires a greater upfront investment as units must be fabricated and paid for before installation can begin |
| Maintenance | Easier to maintain as each component can be accessed and replaced individually | More difficult to maintain as units are larger and more complex to disassemble and replace |
| Thermal Performance | Can achieve good thermal performance with attention to sealing and insulation during assembly | Generally provides better thermal performance due to factory-sealed and insulated pre-made units |
| Structural Movement | May require additional design considerations to accommodate structural movement | Better able to accommodate structural movement as pre-made units can be designed to flex and shift with the building structure |
| Installation Methodology | Requires skilled labour and may require scaffolding or other equipment to reach higher elevations | Requires specialized transportation and lifting equipment, but may require less skilled labour on site |
If you’re still undecided, this list of pro’s and con’s for each approach may be of assistance:
Stick Curtain Walling:
Pros:
- Less expensive due to less specialized equipment and labour.
- Greater flexibility in design and installation.
- Easier to maintain and repair as each component can be accessed and replaced individually.
- Can be adapted to accommodate unique building structures and layouts.
- Can be installed over a longer period of time, allowing for greater control over cash flow and scheduling.
Cons:
- Requires more time on site as each component must be assembled and installed individually.
- May be more difficult to achieve good thermal performance due to the need for careful sealing and insulation during assembly.
- May require additional design considerations to accommodate structural movement and ensure long-term stability.
- Requires skilled labour and may require scaffolding or other equipment to reach higher elevations.
- May be more susceptible to water infiltration and other types of weather damage over time.
Unitised Curtain Walling:
Pros:
- Provides better thermal performance due to factory-sealed and insulated pre-made units.
- Can be installed more quickly on site as pre-made units can be lifted into place.
- Generally more resistant to water infiltration and other types of weather damage.
- Better able to accommodate structural movement as pre-made units can be designed to flex and shift with the building structure.
- Provides a more consistent appearance across the building façade.
Cons:
- More expensive due to prefabrication and specialized transportation/lifting equipment.
- Requires more time and planning off-site for fabrication and shipping.
- May be more difficult to maintain and repair as units are larger and more complex to disassemble and replace.
- Provides less flexibility in design and installation, limiting the ability to adapt to unique building structures and layouts.
- Requires a greater upfront investment as units must be fabricated and paid for before installation can begin.
Whether you’re an architect, builder, or main contractor, choosing the right curtain walling system is critical to the success of your project. At Dortech Architectural Systems Ltd, we have extensive experience in all aspects of curtain walling, from design and installation methodology to cost exercises and manufacture. We work closely with our clients to ensure that our solutions are feasible within their budget, and we provide ongoing remediation and maintenance support to ensure long-term performance. Call us now on 01484 451177 to receive expert assistance with your curtain walling project from Dortech Architectural Systems Ltd.
