ORNL Roof and Attic System Shows Efficient Retrofit Option

The article discusses an innovative roof and attic system developed at Oak Ridge National Laboratory’s Building Technology Center. The research, funded by Texas-based Billy Ellis Roofing, focuses on creating energy-efficient designs suitable for both retrofitting existing buildings and new construction.

The Technology

The system utilizes Thermadeck Styrofoam insulation with a foil-facing that installs over existing roof rafters. According to William Miller of ORNL, the approach combines “ventilation, insulation and radiation” to reduce heat transfer.

How It Works

The reflective foil technology works as a radiant barrier, minimizing both heat gain and loss in attics through several mechanisms:

Radiant Heat Reflection

• Foil surface reflects radiant heat back toward its source
• In summer: reflects solar heat away from living space
• In winter: reflects indoor heat back into home
• Reduces attic temperature extremes year-round

Enhanced Insulation

• Styrofoam provides continuous insulation layer
• Eliminates thermal bridges through framing
• Maintains R-value over existing insulation
• Creates air gap for additional insulation value

Improved Ventilation

• System design maintains proper air flow
• Prevents moisture buildup
• Extends roof lifespan
• Reduces ice dam formation in cold climates

Cost Analysis

Miller emphasized the lifecycle perspective, noting specific cost implications:

Retrofit Applications

The installation would add approximately $6 per 100 square feet to an existing shingle roof (which costs $100 per 100 square feet). This represents:

• 6% cost increase for retrofit
• Payback through energy savings
• Extended roof lifespan
• Improved home comfort

New Construction

New construction applications would cost around $200 per 100 square feet, including:

• Complete roof installation
• Integrated insulation system
• Labor and materials
• Long-term performance warranty

Energy Performance

The system addresses major source of energy loss:

Attic Heat Transfer

Attics represent significant energy challenge because:

• Summer: Extreme heat (often 140°F+) conducts into living space
• Winter: Warm air escapes through inadequate insulation
• Air leakage: Poorly sealed attics allow conditioned air loss
• Thermal bridging: Framing creates insulation gaps

Expected Savings

While specific savings vary by climate and building, benefits include:

• Reduced cooling costs in summer
• Lower heating bills in winter
• More consistent indoor temperatures
• Less HVAC system strain

Broader Context

The article positions this technology as responsive to growing demand for affordable retrofitting solutions, particularly relevant to:

Green Jobs Initiatives

• Installation creates skilled labor opportunities
• Manufacturing supports domestic production
• Maintenance and inspection jobs
• Training and certification programs

Recovery Act Funding

Federal stimulus included significant weatherization funding for:

• Low-income housing improvements
• Energy efficiency retrofits
• Job creation in construction sector
• Reducing energy burden on vulnerable households

Retrofit Advantages

This system offers particular benefits for existing buildings:

Installation Simplicity

• Installs over existing roof structure
• Minimal disruption to occupants
• No interior demolition required
• Compatible with most roof types

Performance Enhancement

• Improves existing insulation effectiveness
• Addresses both conduction and radiation
• Reduces air infiltration
• Extends useful life of existing materials

Economic Accessibility

• Moderate cost increase
• Can be done during normal roof replacement
• Qualifies for energy efficiency incentives
• Provides measurable return on investment

Technical Considerations

Climate Adaptability

The system performs across climate zones:

• Hot climates: Primarily blocks solar heat gain
• Cold climates: Retains indoor heat, prevents ice dams
• Mixed climates: Year-round benefits
• Humid climates: Manages moisture properly

Building Code Compliance

Successful deployment requires:

• Meeting ventilation requirements
• Complying with fire safety standards
• Achieving minimum R-value requirements
• Following installation specifications

Integration with Other Systems

The roof system works alongside:

• Air sealing at attic floor
• Proper ventilation design
• Adequate insulation in walls and floors
• Efficient HVAC equipment

Research Validation

ORNL’s Building Technology Center provides:

• Controlled testing: Measuring actual performance
• Long-term monitoring: Tracking durability
• Climate simulation: Testing various conditions
• Third-party validation: Independent verification

This research backing gives confidence that real-world performance will match expectations.

Market Implications

For Homeowners

• Affordable efficiency improvement
• Can be done during planned roof replacement
• Reduces energy bills
• Improves comfort
• Increases home value

For Contractors

• New revenue opportunity
• Differentiates services
• Relatively simple installation
• Growing market demand
• Partnership with manufacturers

For Utilities

• Reduces peak demand
• Supports conservation goals
• May offer rebate programs
• Helps meet regulatory requirements
• Defers generation capacity needs

Barriers to Adoption

Despite benefits, challenges exist:

Awareness

• Homeowners don’t know about option
• Contractors unfamiliar with installation
• Benefits not well understood
• Competition from conventional approaches

Upfront Cost

• Adds to roof replacement expense
• Payback period may seem long
• Competing budget priorities
• Uncertainty about savings

Market Inertia

• “Good enough” attitude toward existing insulation
• Reluctance to try new approaches
• Lack of standardization
• Limited installer training

Overcoming Barriers

Successful deployment requires:

Education and Outreach

• Consumer awareness campaigns
• Contractor training programs
• Performance data sharing
• Case study development

Financial Incentives

• Utility rebate programs
• Tax credits for efficiency
• Low-interest financing
• Property assessed clean energy (PACE) programs

Market Development

• Manufacturer partnerships
• Installer certification
• Quality standards
• Warranty programs

Environmental Benefits

Beyond energy savings, the system offers:

Carbon Reduction

• Lower energy use = fewer emissions
• Lifecycle benefits exceed production impacts
• Contributes to climate goals
• Scalable impact across building stock

Resource Conservation

• Works with existing structures
• Extends roof lifespan
• Reduces material waste
• Uses recyclable materials

Future Developments

The technology represents starting point for:

Continued Innovation

• Material improvements
• Installation simplification
• Cost reduction
• Performance enhancement

Market Expansion

• Multi-family applications
• Commercial buildings
• Industrial facilities
• Institutional buildings

Lessons for Green Building

This case illustrates important principles:

Retrofits Matter

• New construction is small percentage of building stock
• Existing buildings offer largest efficiency opportunity
• Retrofit solutions must be cost-effective and practical
• Innovation should focus on easier, cheaper retrofits

Integrated Design

• Single measures have limited impact
• Systems thinking essential
• Multiple building envelope improvements needed
• Coordination with mechanical systems important

Economic Viability

• Green solutions must make financial sense
• Moderate cost premiums more adoptable
• Lifecycle analysis should drive decisions
• Value beyond energy savings matters

Conclusion

The ORNL roof and attic system demonstrates that thoughtful engineering can create affordable efficiency improvements for existing buildings. By combining proven technologies (insulation, ventilation, radiant barriers) in innovative ways, researchers developed a practical solution for widespread adoption.

As building energy efficiency becomes increasingly important for climate, economic, and security reasons, innovations like this—moderately priced, technically sound, and readily deployable—will prove essential for transforming the existing building stock.