Drone vs. On-Site Surveys: Showdown or Tag Team?

As you likely know, regular evaluation of your facility assets, such as roofing and pavement, is the cornerstone of effective facilities management. Having accurate, timely data about the condition of these assets is essential for prioritizing projects, designing repairs or replacements, and planning long-term capital investments. Without a clear understanding of asset inventory and health, organizations risk unexpected failures, spending money on the wrong work, and missing opportunities to extend the life of critical infrastructure.

Regular assessments inform building operators on maintenance, repair, and replacement decisions at the building level and provide context for portfolio-wide facility asset management strategies. They’re an important tool for organizations that want to allocate resources effectively, forecast long-term capital expenditures, and ensure that repairs and replacements are performed at the optimal time while maintaining warranties.

However, as technology has evolved, techniques for gathering this vital data have expanded to include both drone-based and on-site surveys. Each offers advantages and disadvantages... and can be used in concert.

Drone Surveys: Speed, Safety, Cost

In recent years, drone surveys have become both viable and popular for facility assessments, especially for large or complex sites. This method can deliver fast, cost-effective, and safe data collection, often with minimal disruption to operations.

Drones can capture high-resolution visual data across expansive or hard-to-reach areas, making them an efficient choice for routine documentation and initial assessments.

Pros

• Speed: Drones can quickly cover large areas or many buildings.
• Cost: These surveys can be significantly less expensive, especially for large or complex sites.
• Access: Drones can survey steep slope, standing seam, tile, or other roof types that could be risky or inaccessible to humans.
• Image Volume: Capturing copious high-resolution imagery provides a comprehensive visual record that supports due diligence and ongoing asset management.

Cons

• Regulations: FAA restrictions near airports can limit drone deployment at some facilities.
• Weather: Similarly, adverse weather can hamper a drone operator.
• Basic Analysis: Drones can identify surface-level issues; however, complex or hidden defects may go undetected.
• Moisture Analysis Limitations: Thermal drones can perform moisture analysis, but these flights are more expensive (ranging from two to three times the cost of a standard drone survey) and may not always be the best choice, depending on the asset or weather conditions.
• (Zero) Preventive Maintenance: Drones don’t have hands!
• Warranties: Many manufacturers require physical, on-site inspections for warranty compliance.

On-Site Surveys: Depth, Detail, Context

On the other hand, on-site surveys, conducted by skilled technicians, are best for a true, in-depth asset evaluation and provide a level of insight that is difficult to match with remote methods.

Having a seasoned eye on a site can reveal hidden issues or details that a drone operator may miss.

Additionally, a technician can perform preventive maintenance, such as cleaning up debris or addressing minor defects, thereby adding even more value to the process.

You’ll want a real human on site when asset longevity, project prioritization, and ensuring compliance with warranty requirements are paramount.

Pros

• An Expert Eye: Technicians identify both surface and hidden defects, perform detailed seam and drainage reviews, and investigate root causes of issues.
• Moisture Analysis Options: Standard on-site surveys include precise moisture detection using infrared (IR) scanning tailored to the roof type and climate.
• Preventive Maintenance: During a site visit, technicians can perform minor maintenance tasks, correcting small problems before they become big ones
• Warranty and Compliance: Manufacturers often require on-site surveys to maintain warranty coverage and ensure regulatory compliance.
• Detailed Reporting: The resulting reports are highly detailed, providing actionable insights and physical verification of inventory and defects.
• Weathering the Weather: On-site teams are better equipped to adapt to changing weather conditions or unexpected site conditions that could delay a drone operator.

Cons

• Time: Manual inspections take longer, especially on large or complex sites.
• Cost: Labor and travel expenses make on-site surveys more expensive, particularly for large-scale assessments that span multiple buildings.
• Safety: Inspectors may face safety risks on steep or hazardous roofs, and some areas may be inaccessible without specialized equipment.

Here’s a Side-by-Side Comparison

So... Which Survey Type is Best and When?

Drone Surveys

Drones can be the right-sized solution when speed, safety, and cost are top of mind. For organizations managing large campuses or portfolios with many facilities, drones offer rapid, high-level assessments, enabling them to prioritize where more detailed follow-up is needed. They are especially useful for capturing routine inventory data and accessing areas that would otherwise be unsafe or pose logistical challenges for humans. 

On-Site Surveys

For deeper insight, moisture analysis, or warranty compliance, a seasoned technician will provide more value. Having a trained professional on site is the best way to gain a comprehensive understanding of asset condition, especially when the stakes are high, such as with aging assets, suspected leaks, or before major capital investments. While they require more time and resources, the long-term value of precise diagnostics and hands-on expertise often outweighs the initial investment, especially for critical or high-value assets.

Taking a Hybrid Approach

In practice, taking a hybrid approach that leverages drone surveys to quickly capture initial data or across a large portfolio, followed by on-site surveys for facilities that warrant closer inspection, can be an effective strategy. This combination maximizes the strengths of both methods, delivering comprehensive data while optimizing costs and supporting a proactive, data-driven asset management strategy.

Maximizing Value: Expert Insight from Mantis Innovation

Drone and on-site surveys are not mutually exclusive; rather, they complement each other. Understanding your assessment goals, operational priorities, and long-term strategy should guide your decision on which route to take. That said, an expert like Mantis helps you get clear on the assessment tools in your toolkit so you can make the best operational and financial decisions in both the short and long term.

Contact us today to discover which survey approach best suits your organization (and when!)