How a Roof Coating Cut a Texas School District’s Electrical Costs by 20%+

Energy savings claims in roofing are common. Verified, multi-year utility data is less common — which is why this case is worth walking through in detail.

The project

Tomball Jr. High School and Tomball High School both received a fluid-applied roof coating application in the summer of 2008. Both tracked electrical costs for a full baseline year before the application, then compared that baseline to the two years that followed.

Tomball Jr. High School — the numbers

• Base year (2007–2008): $619,539
• Year 1 after application: $551,914 — a $67,625 reduction, roughly a 20% decrease
• Year-to-date, Year 2: $530,649 — an $88,890 reduction, roughly a 24% decrease
• Total savings since application: $87,515

Tomball High School — the numbers

• Same base year cost: $619,539
• Year 1 savings: $67,625, an 11% reduction
• Year 2 year-to-date savings: $88,890, a 14% reduction
• Total savings since application: $156,515

Worth noting: unlike the Jr. High project, Tomball High School’s roof was only about 66% coated rather than fully coated. A complete coating application would likely have produced an even larger cost reduction — which tells you something about how directly coverage percentage correlates with energy savings.

Beyond the utility bill

Independent temperature readings taken on-site captured a real-world illustration of why the savings show up: a coated roof surface measured 96.3°F on a day when the surrounding gravel measured 161.7°F — a temperature differential of more than 65 degrees.

Less heat absorbed by the roof means less heat transferred into the building, which means the HVAC system works less to maintain the same indoor temperature.

A roof coating isn’t just a maintenance decision — it’s an energy decision with a payback period you can actually calculate from utility bills, not just from a manufacturer’s projection.