Drones are transforming industries across the globe, and one sector experiencing a significant shift is construction. With an estimated one million drones currently in use across the construction industry, their role in improving safety, efficiency, and data collection is undeniable. In particular, drones are proving to be a valuable tool in facade inspections—a process traditionally carried out using methods such as swing stages, boom lifts, and rope access. These traditional methods often put workers in close proximity to potentially hazardous building facades, but drones can carry out inspections from a safe distance, reducing risk and increasing the speed of data collection. However, despite their advantages, drones have not yet gained widespread acceptance for facade inspections, particularly in cities with restrictive local ordinances.
One of the most prominent regulations to address this issue is New York City’s Local Law 102 of 2020 (Local Law 102), which provides a new framework for facade inspection and includes the use of drones as a potential tool. This article explores the advantages of using drones for facade inspections, the challenges associated with their implementation, and the key considerations that must be taken into account when using drones in this context.
Facade Inspection Safety Program (FSP) – New York City
New York City is home to thousands of historic buildings, many of which are in dire need of frequent inspections to ensure the safety of residents and pedestrians below. The importance of these inspections was tragically highlighted in late 2019 when architect Erica Tishman was killed by falling debris from a 105-year-old high-rise building in Manhattan. This incident prompted the New York City Council to take action, leading to the passage of Local Law 102 of 2020.
This law mandates that all buildings with six or more stories undergo periodic facade inspections, a process known as the Facade Inspection Safety Program (FSP). The law also requires the New York City Department of Buildings (DOB) to study the use of drones for facade inspections, alongside traditional hands-on methods, with the goal of improving the safety and efficiency of these inspections.
Advantages of Drones in Facade Inspections
Drones offer several significant advantages when it comes to facade inspections, primarily in terms of safety and efficiency. Drones are equipped with high-resolution cameras, thermal imaging systems, and other sensors that can quickly and effectively capture visual data, such as videos and images of potential damage or defects on building facades. These tools allow inspectors to spot problems like cracks, wear, or structural issues without the need for workers to scale the building or work at dangerous heights.
The ability to access hard-to-reach areas, such as window sills, balconies, cantilevered structures, and mechanical equipment, further enhances the value of drones. These are areas that would otherwise require scaffolding, rope access, or other time-consuming and potentially hazardous methods. By flying over or around a building with minimal setup, drones can significantly reduce the time and effort required to inspect difficult-to-reach parts of a building.
While drones can capture a wealth of visual data, it’s important to note that the data still needs to be analyzed by a qualified professional to identify defects and hazards. In New York City, these inspections are typically carried out by Qualified Exterior Wall Inspectors (QEWIs), who are licensed design professionals trained to interpret the data captured by drones and take appropriate action.
Key Considerations for Facade Inspection Using Drones
While drones offer impressive benefits, their use in facade inspections is not without challenges. Several factors must be considered to ensure that drone inspections are effective, safe, and compliant with local regulations.
1. GPS Availability
Drones rely on GPS signals to navigate and stabilize during flight. A strong GPS signal is crucial to ensure smooth operation and precise data collection. However, in urban environments like New York City, tall buildings can block GPS signals, leading to interruptions in communication and flight instability. To mitigate this, it is important to plan drone flights in areas with good GPS coverage. In cases where GPS signals are weak or unavailable, alternative methods—such as non-GPS control systems—may be used to maintain control and safety during flight.
2. Number of Facades to Inspect
The efficiency of a drone inspection also depends on the number of building facades that need to be covered and the flight path required to complete the task. For a single facade, a simple up-and-down flight pattern may suffice. However, for larger buildings with multiple facades, drones typically need to fly horizontally (left-to-right) along the facade before moving vertically (top-to-bottom). In some cases, especially with larger or taller buildings, maintaining a clear line of sight can be challenging. When this occurs, the flight plan may need to be split into multiple smaller flights, each focused on a specific facade.
3. Drone Takeoff Locations
Determining the appropriate takeoff location is a critical part of any drone inspection. To reduce risks and ensure a smooth flight, it is essential to identify safe and feasible locations for the drone to launch. In many cases, taking off from the roof of a building is the best option, as it provides ample space and clear access to all facades. However, it is important to consider the altitude and the potential for barometric sensors to report incorrect data at higher altitudes. A thorough site assessment should be carried out to identify the best takeoff location and avoid potential issues.
Complementary Methods and Technologies
While drones are highly effective tools for facade inspection, many countries and regions are adopting a complementary approach that combines drones with other inspection technologies. For example, drones may work in tandem with ground-based sensors or building information modeling (BIM) systems to provide a more comprehensive view of a building’s condition. The integration of multiple technologies ensures that inspectors have all the necessary data to make informed decisions and carry out maintenance or repairs efficiently.
Conclusion
Drones represent a significant advancement in the field of facade inspection, offering numerous advantages over traditional methods. From enhancing safety by reducing the need for workers to work at heights to increasing efficiency by allowing inspectors to quickly access hard-to-reach areas, drones are revolutionizing the way facade inspections are conducted. However, to fully realize the potential of drones in this context, it is essential to address key considerations such as GPS availability, flight paths, and safe takeoff locations. As local regulations, such as New York City’s Local Law 102 of 2020, evolve to accommodate the use of drones, the construction industry is poised to embrace this technology more widely, improving both the safety and effectiveness of facade inspections for years to come.