1 the emerging role of the roof in a sustainable world dr. james l. hoff research director craig...

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The Emerging Role of the Roof in a Sustainable World

Dr. James L. HoffResearch Director

Craig SilvertoothExecutive Director

2Few Major Building Systems Offer As Many Energy & Environmental Benefits…

… And Few Major Building Systems Are Installed as Frequently as Roofs!


Why Sustainable Roofing?

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Energy / Environmental Benefits

Increased Energy Efficiency

Clean Energy Production

Cleaner Air & Water

Reduced Material Waste

Extended Building Life Cycle

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1 Billion Sq. Ft.

3 Billion Sq. Ft.

New Construction

Re-Roofing North American Low-Slope Roofing Market

(Billions of Square Feet, 2006)

Each year, 4 billion square feet of commercial roofs are installed in North America, exceeding new commercial construction by a factor of 4!


The Roofing Multiplier Effect

Source: TEGNOS Research, Inc. 2008

51. High R Roofs

2. Cool Roofs

3. Rooftop Energy Production

4. Roof Daylighting

5. Rooftop Water Management

6. Roofing Material Management

7. Roof Life Cycle Management


Sustainable Roofing Opportunities

Energy

Environment

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High R Roofs

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High R Roofs

What is a High R Roof?

“A High R Roof is a roof that provides a level of thermal resistance (R) substantially higher than current minimum standards and practices.”

Center For Environmental Innovation In Roofing

Knowledge Center( http://roofknowledge.org/main/energyefficientroofs/highrroofs/whatisahighrroof )

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High R Roofs

Why High R Roofs?

Globally:

Locally:

• Most effective way to reduce green house gas emissions between now and 2030

• Increasing federal, state & local incentives available

• Established economic payback

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ASHRAEClimate

Zone

1234567

“Old” ASHRAE 90.1 -1999

10151515152025

“New”ASHRAE

90.1 - 2007

15202020202530

TypicalCity

Example

MiamiHoustonAtlanta

BaltimoreChicago

MilwaukeeMinneapolis

Minimum R-Values:

Low-Slope Commercial Roof Insulation

High R Roofs

Current ASHRAE Minimum Standards

First major increase in roof R values since 1972…

“Proposed”ASHRAE 189.1P1

20252525253035

… with more increases to follow soon

1 Third public review draft, May, 2009.

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High R Roofs

R-Value & LEED

ASHRAE 90.1-2007LEED 2009 Minimum**

13579

1113151719

Energy SavingsTarget

Baseline10%

12%16%20%24%28%32%36%40%44%48%

ProportionalRoof R-Value*

20.022.2

22.723.825.026.327.829.431.333.335.738.5

Source: Center for Environmental Innovation in Roofing. Note: Chart is applicable for buildings within ASHRAE Climate Zones 2 through 5 - from Houston, Texas to Chicago, Illinois. Target energy savings and proportional roof insulation R-values will be lower in Zone 1 and higher in Zones 6 and 7. For a detailed analysis of a specific building in a specific location, ASHRAE 90.1-2007 should be consulted.

LEED 2009 (v3)

New Building Energy Savings Targets(ASHRAE Climate Zones 2 through 5)

* Roof R-Value Needed to Achieve Proportional Energy Savings **Minimum LEED 2009 (v3) Prerequisite

ProportionalRoof U-Value*

0.0500.045

0.0440.0420.0400.0380.0360.0340.0320.0300.0280.026

LEED Points

Available:

(EA Credit 1)

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High R Roofs

R-Value & LEED

ASHRAE 90.1-2007LEED 2009 Minimum**

13579

1113151719

Energy SavingsTarget

Baseline5%

10%12%16%20%24%28%32%36%40%44%

ProportionalRoof R-Value*

20.021.1

22.222.723.825.026.327.829.431.333.335.7

Source: Center for Environmental Innovation in Roofing. Note: Chart is applicable for buildings within ASHRAE Climate Zones 2 through 5 - from Houston, Texas to Chicago, Illinois. Target energy savings and proportional roof insulation R-values will be lower in Zone 1 and higher in Zones 6 and 7. For a detailed analysis of a specific building in a specific location, ASHRAE 90.1-2007 should be consulted.

LEED 2009 (v3)

Existing Building Energy Savings Targets(ASHRAE Climate Zones 2 through 5)

* Roof R-Value Needed to Achieve Proportional Energy Savings **Minimum LEED 2009 (v3) Prerequisite

ProportionalRoof U-Value*

0.0500.045

0.0440.0420.0400.0380.0360.0340.0320.0300.0280.026

LEED Points

Available:

(EA Credit 1)

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Cool Roofs

13“A cool roof interacts with solar radiation to reduce solar heat transfer from the roof into the building and reduce ambient air temperatures above the roof surface.”

Center For Environmental Innovation In Roofing

Knowledge Center(http://roofknowledge.org/main/energyefficientroofs/coolroofs/whatisacoolroof)

Cool Roofs

What is a Cool Roof?

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Cool Roofs

Why Cool Roofs?

• Building Energy Savings

• Heat Island Reduction

• Peak Electricity Reduction

Atlanta, GA

Standard Rate: Summer Peak Rate:

$ $$$

1972 1993

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Cool Roofs

Where are Cool Roofs Useful?

• In climates with warm, sunny summers

• In areas considered Urban Heat Islands

• In areas with increased peak electricity rates, demand charges, and interruptible supply agreements

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Cool Roofs

Cool Roofing Options

Cool Vegetated

Roofs

Reducing Heat Build-Up By Reflecting the

Sun’s Rays

Cool Reflective

Roofs

A Traditional Alternative Using Transpiration & Thermal Mass

LEED 2009 Cool Roofing Options1

1 LEED SS Credit 7.2

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Cool Roofs

Cool Roofing Options

Cool Reflective Cool Vegetated

+ Variety of material and color options

+ Little or no initial cost premium

– May lose some reflectivity with age

+ Potential environmental benefits in addition to cool roofing

– Increased weight and depth requirements

– Cost premium

LEED 2009 Cool Roofing Options1

1 LEED SS Credit 7.2

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Green Roofing Opportunities

Rooftop Energy

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Rooftop Energy

Why Rooftop Energy?

• Direct Access to Sun and Wind• Low Cost “Energy Real Estate”• Close to the Customer / Close to the Grid• Expanded Federal, State & Local Incentives• Rapidly Approaching “Grid Parity”

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Rooftop Energy

Current Technologies

• Photovoltaics (PV)

• Solar Thermal

• Combined PV / Solar Thermal

• Roof-Mounted Wind Turbines

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Roof Daylighting

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Roof Daylighting

Why Roof Daylighting?

• Easy to install or retrofit in typical low-rise commercial buildings

• Proven energy savings / high return on investment when integrated with building lighting system

• Increasing federal, state & local incentives available

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Roof Daylighting

Current Technologies

Passive Systems Capture, Reflect &

Direct Daylight

Active Systems

Follow the Sun to Maximize

Sunlight Capture

Integrated Systems Combine Solar and

Electric Lighting in an Integrated Package

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Rooftop Water Management

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Why Rooftop Water Management?

• Reduced storm water runoff

• Improved water quality in rivers and lakes

Cities with Combined Sewer Systems

Combined sewer system are remnants of the country's early infrastructure and so are typically found in older communities. Combined sewer systems serve roughly 772 communities , home to over 40 million US citizens.

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Water Management Options

Vegetated Options Ballasted Options

Retaining Storm Water Runoff with Planting Media &

Moisture Retention Mats

Retaining Storm Water Runoff with Moisture

Retention Mats

… Plus Hybrid Vegetated / Ballasted Options

Combining the best of both alternatives

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Water Management Options

Vegetated Ballasted Hybrid

+ Possible LEED credits (SS Credits 6.1 & 6.2)

+ LEED cool roof credit (SS credit 7.2)

– Cost premium

+ Opportunity to optimize economics & benefits

+ LEED cool roof credit for 50% vegetated

+ Possible LEED credit (SS Credits 6.1)

+ Low initial cost

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Roofing Material Management

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Why Roofing Material Management?

• 160 Million Tons Of Construction Waste

• 40 Million Tons of Roofing Waste • 25%+ of Total Construction Waste

Annual U.S. Landfill Waste

Source: US EPA (1998)

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Current Recycling Options

• Asphalt Shingles / Wood Shakes: Local and regional recyclers are developing roof recycling programs.

• Single-Plies: Several roofing manufacturers and trade associations have initiated recycling programs for some single-ply membranes.

• Metal Roofing: The metal industries have well-established recycling programs.

• Insulation: A new organization has started a successful national recycling program for foam insulation boards

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Roof Life Cycle Management

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• Roof Asset Management

• Preventative Maintenance Programs

Not only extend the roof life cycle, but the life cycle of the entire building

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Sustainable Roofing Resources

• Online Energy Calculators

• Federal, State & Local Energy Incentives

• Federal Stimulus Project Resources

• Cool Roofing Resources

• Renewable Energy & Daylighting Resources

• Vegetated Roofs / Water Management Resources

• Roof Recycling Resources

• Roof Life Cycle Management Resources

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• High R Insulation & Energy Savings

– NRCA “EnergyWise” (http://energywise.specright.net/)

– Calculates roof energy costs per ASHRAE 90.1

– Allows comparison between roofing alternatives

– Provides printable summary with charts & graphs

• Cool Roofing & Energy Savings

– DOE Cool Roofing Calculator (http://www.ornl.gov/sci/roofs+walls/facts/CoolCalcEnergy.htm)

– Calculates annual heating / cooling savings for cool roofs

– Allows comparison between roofing alternatives

– “CoolPeak” option for areas with peak demand charges


Online Energy Calculators

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Federal, State & Local Energy Incentives

• Federal Tax Incentives Assistance Project

– http://www.energytaxincentives.org/

– Information on Commercial Building Energy Efficiency Tax Deduction

– Information on Solar Energy Investment Tax Credit

• Database of State Incentives for Renewables and Efficiency

– http://www.dsireusa.org/

– Covers both energy efficiency & renewable energy incentives

– Includes state and local programs, including utilities

• Green Roofs Tree of Knowledge

– http://greenroofs.org/grtok/index.php

– Covers community incentives for vegetated roofing systems

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Federal Stimulus Information

• Construction Stimulus Special Section

– http://www.construction.com/stimulus/default.asp

– Information by market sector (Federal buildings, state projects, local schools)

– Sponsored by McGraw Hill

• Federal Stimulus Construction Project Leads

– http://www.reedconstructiondata.com/construction-project-leads/infrastructure/

– Free downloadable regional reports

– Sponsored by Reed Construction Data

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Cool Roofs

• Cool Roof Rating Council

– http://www.coolroofs.org

– Third-party certifier of cool reflective roof ratings

– Resource for cool reflective roofing standards & incentives

• Energy Star Roof Program

– http://www.energystar.gov/index.cfm?c=roof_prods.pr_roof_products

– Home of EPA Energy Star cool roofing product registry

• LBL Heat Island Group

– http://eetd.lbl.gov/heatisland/

– Resource for heat island / cool roofing research

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• Interstate Renewable Energy Council

– http://www.irecusa.org/

• U.S. Department of Energy Solar Energies Technology Program

– http://www1.eere.energy.gov/solar/

• Whole Building Design Guide: Building-Integrated Photovoltaics (BIPV)

– http://www.wbdg.org/resources/bipv.php

• Daylighting Collaborative

– http://www.daylighting.org


Renewable Energy & Daylighting

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Vegetated Roofs / Water Management

• Penn State Center for Green Roof Research– http://hortweb.cas.psu.edu/research/greenroofcenter

• Green Roofs for Healthy Cities– http://www.greenroofs.org

• NRCA Green Roof Systems Manual– http://www.nrca.net

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Roof Recycling • Construction Waste Management Database

– Sponsored by Whole Building Design Guide

– National database with state and local sources by material

– (http://www.wbdg.org/tools/cwm.php?c=6)

• Foam Insulation Recycling– Nationwide Foam (http://www.nationwidefoam.com/)

• Single-Ply Roof Recycling– Vinyl Roofing Division, CFFA (http://www.vinylroofs.org/)

– EPDM Roofing Association (http://epdmroofs.org)

• Metal Roof Recycling– Metal Construction Association (http://www.metalconstruction.org/)

• Asphalt Shingle & Wood Shake Recycling– American Roofing Recyclers (http://www.roofingrecyclers.com )

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• Whole Building Design Guide

– Building Commissioning

– Facilities Operation & Maintenance

– http://www.wbdg.org/index.php

• National Roofing Contractors Association Inspection Manuals

– Built-Up and Modified Bitumen Roofing Systems

– Existing Single-Ply Roofing Systems

– Spray Polyurethane Foam-Based Roofing Systems

– Steep-Slope & Low-Slope Architectural Metal Panel Roof Assemblies

– http://www.nrca.net

WBDGWHOLE BUILDING DESIGN GUIDE

1 the emerging role of the roof in a sustainable world dr. james l. hoff research director craig...

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