Bolt-on balconies are a type of balcony system where a steel-framed structure is fixed directly to a building façade. These balconies can be either cantilevered or self-supporting, typically incorporating a timber or open mesh deck.
While widely used, bolt-on steel balconies can present challenges in installation, weight, and on-site coordination. As a result, many developers are now considering aluminium balcony systems as a more efficient alternative.
What Are Bolt-On Steel Balconies?
This type of balcony is a steel-framed structure bolted on to the building. Balconies can be cantilever or self-supporting with a timber or open mesh deck.
Bolt-on balconies are often specified where:
A traditional steel solution is preferred
Structural integration is required
A cantilever aesthetic is desired
However, their reliance on steel construction introduces a number of practical and performance considerations.
Disadvantages of Steel Bolt-On Balconies
Traditional cantilever steel bolt-on balconies offer the aesthetic appeal of no visible means of support. However, there are a number of disadvantages associated with this option and with the self-supporting type of bolt-on steel balcony:
Time-consuming installation
Our Glide-On™ technology is proven to be up to 50% more efficient, allowing up to 34 balconies to be installed in just 6 hours compared with only 5–10 steel bolt-on balconies per day.
Extensive finishing works required
Unlike bolt-on balconies, our Cassettes® come complete with preassembled soffits, fascia and decks, reducing finishing works and associated costs.
Heavy structural weight
The weight of steel balconies requires more brackets and connections to the main structure. Our aluminium Cassettes® are approximately half the weight, reducing anchor points and minimising cold bridging risk.
Visible welds and fixings
Steel balconies often expose fixings. Our Cassette® balconies are engineered with discreet connections and preassembled soffits for a clean finish.
Health and safety risks during installation
Installers must often work beneath the balcony while it is supported by a crane. Our Glide-On™ balconies eliminate this by allowing installation without fixing from below under live load.
Alignment and tolerance issues
Traditional RC frames can lead to misalignment, causing delays and additional cost. We provide templates with cast-in anchors so balconies fit first time.
Limited adjustment flexibility
Steel balconies require precise hole alignment, whereas our Cassettes® allow adjustment both horizontally and vertically.
Multiple trades required on site
Steel systems require coordination of several trades. Our balconies arrive fully assembled, reducing site complexity.
Higher overall cost
When considering programme time, crane use, and finishing works, bolt-on balconies are typically less cost-effective than factory-finished systems.
Steel Bolt-On Balcony Installation
Below is an example of a traditional steel bolt-on balcony installation. Note the reliance on crane positioning, manual fixing, and the need for operatives working beneath the structure.
Steel vs Aluminium Balconies
Traditional bolt-on balconies are typically constructed from steel, whereas modern systems increasingly use aluminium for improved efficiency.
