BY: ZERO MURRAY*
When designing a facade access system solution, Builders, Building Owners and Architects often are choosing between two options: Rope Access Systems or BMU’s.
It is up for debate as to which working at height solution is better, but it will depend on your circumstances and the site you are operating on. The right solution for the building will be entirely dependent on several factors, such as budget, maintenance requirements, roof space, and facade structure. Rope access is often a more cost-effective and flexible option for small to medium buildings with simple facades.
The biggest comparison between BMUs and Rope Access Systems is the initial cost outlay. BMUs can be expensive to install and maintain, as well as the high sub structural load requirements.
It is estimated over a 10-year cycle, the Rope Access System will generally be a fraction of the costs to maintain as the BMU system, however, when the BMU system is used regularly or the building has a large complex facade, the advantages of a BMU may outweigh the cost savings of a Rope Access System in certain situations.
Rope Access Systems, on the other hand, provide a lower cost and more flexible solution for small to medium buildings and non-complex facade buildings.
The cost of installing a BMU is significantly higher, ranging from $150,000 to $400,000, compared to $10,000 to $50,000 for a Rope Access System. The estimated annual maintenance cost for a BMU is also significantly higher, ranging from $2,500 to $4,000 compared to $900 to $1,800 for a Rope Access System. Overall, the cost savings of a Rope Access Systems over a BMU are significant, with a much lower initial outlay and ongoing maintenance costs.
|LIKE FOR LIKE||BMU SYSTEM||ROPE ACCESS SYSTEM|
|Induction Time||1 hour||1 hour|
|Perform Works Time||6 hours||6 hours|
|Clear Site Time||1 hour||1 hour|
|System Installation Cost||$150,000 – $400,000||$10,000 – $50,000|
|Estimated Average Annual Maintenance Cost||$2,500 – $4,000||$900 – $1,800|
|ESTIMATED TOTAL TIME||8 hours||8 hours|
As you can see, the timelines for both BMUs and Rope Access Systems are the same, with an induction time of 1 hour, 6 hours to perform the work, and 1 hour to clear the site equaling an 8 hour day. However, installation times can be significantly longer when installing BMUs.
BMUs PROS & CONS
- Accessibility: Provides safe and easy access to all parts of the building, including hard-to-reach areas.
- Efficiency: Maintenance work can be done quickly and efficiently, minimising disruptions to occupants.
- Safety: Provides a secure platform for low trained workers, protecting them from falls and other accidents.
- Flexibility: Can be customised to suit the needs of most buildings.
- Glass Replacement: Good glass replacement capabilities but has limitations for some under-hang sections of the building.
- Cost: Expensive to install, operate, and maintain. High maintenance costs. 4 compliance visits and one full service required annually.
- Space: Requires a large amount of space on the roof of the building and a high substructural load requirement.
- Reliability: Much greater risk of breakdown due to complex machinery.
- Retro-fit: Difficult to add BMUs to existing building or structures.
- Visibility: Can be unsightly and detract from the aesthetic of a building.
- Weather: Only suitable for use in good weather conditions.
ROPE ACCESS PROS & CONS
- Accessibility: Can access areas that are difficult or impossible to reach with a BMU.
- Efficiency: Can be set up quickly and easily, reducing downtime for the building and has the ability to have multiple workers on the one site at one time. •
- Cost: Generally less expensive to install and maintain. Low inspection costs. One compliance testing visit required annually.
- Flexibility: Can be used on a wide range of building types and sizes and can be customised to suit the needs of most buildings.
- Safety: Properly trained rope access technicians can work in a safe and controlled manner.
- Visibility: Generally less visible than BMUs.
- Weather: Can be used in a wider range of weather conditions compared to BMUs.
- Glass Replacement: Good glass replacement capabilities especially on some under-hang sections but has some load limitations.
- Space: The working area can sometimes be more limited but is remedied by increasing the number of technicians working at any one time. Sometimes difficult to access complex facades.
- Efficiency: Less capacity for heavy tools and equipment. Limitations for glass replacement on some high-rise buildings but still possible, although it requires a specialised team.
As both industries move forward, a combination of BMU and Rope Access Systems is often the most practical solution for high-rise buildings with complex facades. The combination of both systems provides the best of both worlds and allows for a more efficient and cost-effective solution for building access and maintenance. In conclusion, the choice between BMU and Rope Access Systems depends on several factors, including the type of building, the nature of the maintenance work, and the budget.
An excellent example of successful collaboration is the Quay Quarter Tower project, which has won multiple awards and is located in the Sydney CBD. The project involved a collaboration between the developer MULTIPLEX, the BMU company FARRA Engineering, as well as SAYFA, the design consultants and manufacturers for difficult access systems, who worked together to identify, troubleshoot, and execute the complex facade access requirements of the building.
The primary goal of the project was to ensure that two different access systems could work seamlessly without interfering with each other’s parameters. The successful execution of this project highlights the importance of collaboration in achieving complex construction objectives, and serves as an inspiration for future similar projects.