Energy-Efficient Roofing: How Cool Roofs Save Money
With energy costs continuing to rise, building owners are looking for ways to reduce HVAC expenses. Cool roofing technology offers one of the most impactful energy-saving opportunities available. By reflecting sunlight rather than absorbing it, cool roofs can dramatically reduce cooling loads and extend roof lifespan.
What Makes a Roof "Cool"?
Cool roofs have two key properties: high solar reflectance (reflecting sunlight) and high thermal emittance (releasing absorbed heat). A traditional black roof might reach 150°F on a summer day, while a cool white roof might stay below 100°F under the same conditions.
- Solar Reflectance Index (SRI) measures both reflectance and emittance
- Cool roofs typically have SRI values above 78
- White TPO and PVC membranes are inherently cool
- Reflective coatings can upgrade existing dark roofs
Energy Savings Potential
The energy savings from cool roofs depend on several factors: building size, insulation levels, cooling equipment efficiency, climate zone, and utility rates. In the Chicago area, buildings with significant cooling loads can see annual savings of $0.10-0.50 per square foot of roof area.
Real-World Example
A 50,000 square foot warehouse switching from a dark EPDM roof to white TPO could save $5,000-25,000 annually on cooling costs, depending on building use and HVAC efficiency.
Beyond Energy: Additional Benefits
- Reduced heat island effect benefits surrounding areas
- Lower roof surface temperatures extend membrane life
- May qualify for utility rebates and LEED credits
- Improves occupant comfort in top-floor spaces
- Reduces strain on HVAC equipment, extending its life
When Cool Roofs Make the Most Sense
Cool roofs provide the greatest return for buildings with high cooling loads, large roof areas relative to building volume, older or less efficient HVAC systems, and locations with high electricity rates. Buildings that primarily need heating rather than cooling may see less benefit.
Upgrading Your Existing Roof
If your current roof is in good condition but not reflective, coating options exist. Reflective elastomeric or acrylic coatings can be applied over many existing roof types, providing cool roof benefits without full replacement. These coatings typically last 10-15 years and can be reapplied.
When it's time for full replacement, choosing a cool roof system adds minimal cost while providing decades of energy savings. For most commercial buildings in our service area, the investment pays for itself within 3-7 years.
