The Future of Roofing

Gone are the times that roofing systems were only a simple part of a building. Roofing systems are increasingly trending toward saving money and energy, and providing other environmental benefits. And this trend should continue.

White is the New Green

While in London in 2009, President Obama’s Energy Secretary Steven Chu, told his former colleagues at the Lawrence Berkeley National Laboratory that painting roofs white to reflect sunlight can make a huge difference to global warming.

Energy Secretary Steven Chu

“There’s a friend of mine, a colleague of mine, Art Rosenfeld, who’s pushing very hard for a geo-engineering we all believe will be completely benign, and that’s when you have a flat-top roof building, make it white. “Now, you smile, but he’s done a calculation, and if you take all the buildings and make their roofs white and if you make the pavement more of a concrete type of color rather than a black type of color, and you do this uniformly . . . it’s the equivalent of reducing the carbon emissions due to all the cars on the road for 11 years.”

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Yet Another Green Design Tool

Many are at least somewhat familiar with green design programs such as LEED® and Green Globes. The ENERGY STAR® Roof Products Program and the Cool Roof Ratings Council have been providing lists of qualified or rated products for years now, however, recently there have been some questions about another design guide and what it has to say about cool roofing.

The Advanced Energy Design Guides were developed by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). The guides are a series of publications designed to provide recommendations for achieving energy savings above and beyond the minimum code requirements of ANSI/ASHRAE/IESNA Standard 90.1-1999. They are intended for contractors and designers of small buildings and provide a simple approach to achieve energy savings without utilizing complex calculations or analysis.

The guides give general recommendations in the Building Envelope sections stating that cool or “solar reflective” roofs help reduce energy usage. They do not offer the specificity of LEED or Green Globes, rather they make general recommendations like “increase roof surface reflectance and emittance.”

They also provide useful charts and climate maps that indicate relative performance of various types of roofing products and areas of the country that may benefit most from cool roofing systems.

The Advanced Energy Design Guides are available as free downloads from Highly reflective white membranes, such as what’s used in the Duro-Last® Cool Zone® roofing system offer a great opportunity for owners of small buildings to achieve real energy savings.

No News Is No News

Good news for home owners! The Tax Relief, Unemployment Insurance Reauthorization, and Job Creation Act of 2010 extended the residential energy efficiency tax credits.

The bill allows a tax credit for up to 10% of the amount paid by the taxpayer for qualified nonbusiness energy efficiency improvements to a maximum lifetime limit of $500. If more than $500 of these tax credits were already taken between 2006 and 2010, there can be no further credits taken. This is a reduction from the $1,500 credit allowed in the original bill.

The credit applies to principal residential property placed in service between January 1, 2011 and December 31, 2011.

Among the qualifying improvements are windows and doors, metal and asphalt roofing, insulation, HVAC equipment, water heaters, geothermal heat pumps, and solar energy systems. All must be ENERGY STAR® qualified products. Unfortunately, single-ply membranes, such as the Duro-Last® Cool Zone® roofing system still do not qualify for the residential energy efficiency tax credit. However tax policy and incentive programs are constantly being revised. We’ll stay on top of things and report on changes when they occur.

PTOs: New to the Roofing Market?

Be careful what you read! Are PTOs a new competitor in the roofing market? No, it’s an acronym with some misplaced letters from the title of a poorly written magazine article. So much marketing misinformation gets presented as fact that it’s a wonder anyone can make an informed roofing decision. Following is some information that may help in assessing the credibility of statements made about roofing.

PVC roofing is made from two basic components: fossil fuel and salt. Fossil fuel is converted to ethylene and rock salt goes through electrolysis to retrieve chlorine – one of the most abundant elements on earth. These components are combined to produce the vinyl chloride monomer which is used with other components to create PVC membrane.

Europe was early to adopt PVC roofing as a single-ply system of choice. Contrary to some claims, PVC roofing is being sold throughout Europe and in fact enjoys by far the largest market share of any of the thermoplastic single-plies.

ENERGY STAR®, the Cool Roof Rating Council, Green Globes, and the U.S. Green Building Council, among other organizations, have developed programs to help specifiers and consumers make informed roofing decisions. The USGBC developed the Leadership in Energy and Environmental Design (LEED®) Rating System several years ago. LEED aids in the design and construction of buildings that minimize negative impacts on occupants and the environment

PVC membranes offer a host of relevant benefits:

  • White PVC membranes are among the most reflective on the market. The Duro-Last Cool Zone® membrane’s Solar Reflectance Index (SRI) of over 110 exceeds LEED requirements for Sustainable Sites Credit 7.2.
  • Recyclability is also a key element of many green design programs, and unlike other roofing materials, there are well-established programs for recycling PVC roofing membrane, including one offered by Duro-Last.
  • Because of its chlorine component, PVC is inherently flame resistant, unlike many other roofing products with higher carbon content. This makes fire ratings easier to achieve, and means that PVC roofing in general is less likely to emit toxic gases than other materials in building fires.
  • PVC membranes are highly flexible and can be custom-prefabricated before reaching the rooftop for installation. This reduces rooftop labor by minimizing jobsite welding by contractors. In addition, seam integrity is more reliable than for stiffer membranes that are made from materials other than PVC.

So, when evaluating systems for your next commercial roofing project, you may want to ask yourself “Why go with the PTO?” Check the facts; don’t be misled by misinformation, and make an informed decision.

Flooded With Sunlight: Reducing Urban Heat Islands with Cool Roofing

U.S. Department of Energy Secretary Steven Chu is a big proponent of cool roofing. In his July 2010 announcement, Chu made it clear that he was going to push for the installation of cool roofing systems on all federal buildings to help reduce energy usage. Secretary Chu is well-informed about cool roofing because he was formerly the head of Lawrence Berkeley National Laboratories (LBNL), the entity that pioneered the study of Urban Heat Islands (UHIs).

Not only will cool roofing reduce building energy usage, it will also help mitigate the UHI effect. The UHI effect is the tendency for urban areas to be hotter than surrounding areas. LBNL found that the average temperature on a hot summer day will be seven degrees warmer in North American urban areas than surrounding rural areas. During an extended heat wave the difference can be even more pronounced. Studies have shown that there are three primary factors that cause the majority of the UHI effect.


The first factor is that urban areas have less vegetation than rural areas. Not only do trees and shrubs provide shade, but thriving vegetation keeps itself cool through a process called evapotranspiration. Similar to how the human body sweats to keep itself cool, vegetation releases moisture to stay cool. About 56%, or almost four degrees, of the seven degree difference is due to less vegetation in urban areas than rural.

Dark Pavement

Many might think that dark pavement would account for much of the UHI effect. While walking down a city street, one can feel the heat radiating up. But dark pavement accounts for only 6%, or less than one-half degree, of the seven degree difference.

Dark Roofing

Roofing takes up a lot of surface area in urban areas, but roofing is not often considered a source of urban heat because it is “out of sight, out of mind.” Yet dark roofing accounts for 38%, or almost three degrees, of the seven degree difference associated with UHIs.

Many cities have attempted to increase green space and vegetation through civic programs and building codes, but for every tree planted or park developed there is much more green space that succumbs to urban sprawl. Green space initiatives are at best a long term means of mitigating UHIs and can entail significant expense.

Paving products made from lighter colored materials are available, but implementing these measures is capital intensive and can take years to accomplish. And considering the relatively minor role that paving plays in UHIs, there are options that provide more bang for the buck.

Installation of cool roofing during initial construction or when re-roofing offers immediate benefits, not only toward mitigation of UHIs but to the building owner in the form of energy savings. A good roofing system is essential for protecting any building from the elements. Selecting and installing a cool roofing system is easy to accomplish, inexpensive relative to other UHI mitigation efforts, and provides benefits immediately.

Even in northern geographic areas where net energy savings may be minimal, cool roofing systems offer significant benefits that may be less tangible but are essential to the long term performance and durability of the roof, insulation and HVAC equipment.

Green Globes® Is Now An ANSI Standard

In April, the Green Building Initiative received word that its Green Globes® green design guideline was approved as an American National Standard. The new standard is not yet part of Green Globes’ online system, but it will be in the future. It is set up as a tool to assess the designer’s plans rather than to instruct in green design. There are four achievement levels: Level 1 is 35%-54% of the total points, Level 2 is 55%-69%, Level 3 is 70%-84% and level 4 is 85-100%. Achievement levels are based on percentage rather than number of points to allow for a difference in the points total in the event there are “non-applicable” circumstances; e.g. there are no oil fired burners on site, or local codes override certain criterion.

As compared to LEED®, the credit categories are weighted based on importance as determined by the review committee and industry input. A certain percentage of points are required in each category in order to reduce/avoid “point chasing.” There are five categories where Duro-Last can directly influence points and several other areas where Duro-Last or one of our sister companies can have a somewhat indirect influence.

Section 7.2.2 Heat Island Effect

Points can be obtained for having vegetative roofing or a reflective surface with SRI of 78 or greater on various proportions of the roof deck.

Section 8 Energy

Points can be obtained using either a Performance Design path or a Prescriptive Design Path. Duro-Last can help with section 8.2.3 Power Demand Reduction. Above deck insulation can help with section 8.4.1 Thermal Resistance and Transmittance.

Section 10.1.2 Materials Content Assemblies

Points can be obtained when pre or post-consumer recycled content of an assembly accounts for 1% or more of building materials. Number of points achieved goes up with higher percentages.

Section 10.1.4 Transportation of Processed or Manufactured Materials

Points can be obtained when 1% or more of materials and products used in the building were processed or manufactured within 500 miles or if shipped by rail or water within 1500 miles. The number of points allowed goes up with greater percentages.

Section10.7.1.1 Roofing Membrane Assemblies and Systems (and) Section Flashings

Points can be obtained by installing according to manufacturer’s recommendations and inspecting according to:

  1. ARMA/NRCA Manual for Roof Inspection
  2. SPRI/NRCA Manual for Roof Inspection
  3. SMACNA’s Architectural Sheet Metal Manual

In most instances, by installing a white Duro-Last roof according to our standards and performing the approved inspections, we can help directly with obtaining as many as 16 points and indirectly with several more. When there are as many as 1000 total points, that doesn’t sound like a lot. But there are so many categories and options that no one action or product can have an overwhelming influence.

All in all, the standard was well done, is easy to use and in general is a much better product than LEED which is not a recognized green design standard. When GBI gets the standard consolidated with its online Green Globes it should be even more user-friendly.

Cause and Effect (or Robbing Peter to Pay Paul)

Energy savings analysis has been around for years. There are any number of Internet-based calculators, formulas and procedures for estimating the savings associated with products or actions undertaken to reduce or avoid energy usage. Energy savings is but one component of a much more comprehensive analytical process referred to as life cycle analysis or LCA. But LCA is not nearly so well-defined. Unlike energy savings analysis, which considers a limited number of variables that can be reasonably well defined and quantified, there is no uniform procedure for LCA.

There are some Internet-based calculators for LCA, but they range from being over-simplified to exceedingly complex; from being biased toward individual products or special interests to being overly generic and meaningless. Some approaches to LCA only consider short term direct financial burdens while others consider more indirect or subjective costs both upstream and downstream in the life of a product.

A mainly financial LCA approach for comparing roof systems might consider the following:

  • Installation – product cost, installation costs, tear-off costs, disposal costs, business disruption costs.
  • Long Term Durability – routine maintenance costs, roof replacement costs.
  • Repairs – roof repair costs, interior damage repair costs.
  • Energy Savings – estimated savings, rebates and incentives.
  • Warranty – cost premiums.

On the other hand, a highly comprehensive environmental-based approach might entail the evaluation of all material and energy inputs and outputs at every stage, from the creation of natural resources through extraction, manufacture, use, and demolition, and disposal of a product. Consider the complexity of the following extreme LCA flow example:

BANG ? Earth Appears ? Life Begins ? Dinosaurs/Other Creatures Appear ? Creatures Die/Turn Into Fossil Fuels ? Human Race Appears/Evolves ? Resources Extracted (fossil fuels, salt, etc.) ? Resources Transported to be Processed/Refined ? Process/Refine Raw Materials ? Process Components (film, scrim) ? Produce Product Components (membrane, rigid parts, etc.) ? Transport for Fabrication ? Fabricate and Assemble The Duro-Last® Cool Zone® Roofing System ? Deliver to Jobsite ? Installation ? Roof In Action (energy savings/heat island mitigation/global warming or cooling or both) ? End of Useful Life ? Removal/Disposal ? Recycle and/or Transport to Landfill ? 100,000 to 1 Million Years of Decay and Revert to Fossil Fuels, Salt, etc. ? Another BANG!? Or Re-Extraction?

Although this second example seems extreme or absurd, it makes the point that there can be limitless considerations in a comprehensive LCA. The difficulty comes in deciding how far to go and making fair and objective assumptions of all criteria at each stage in the life of the product or system. One of the best things LCA helps accomplish is identification of opportunities for improvement. The important thing to remember in addressing this continuous improvement process is to remember that every action has a reaction, so don’t rob Peter to pay Pa

Will Climategate Freeze Up Cool Roofing Sales?

In case you haven’t seen it in the news recently, another conspiracy and cover-up has been discovered and is being referred to as “Climategate.” It seems there has been some manipulation of the database of historical temperature data that has been used to support the concept of global warming. A string of emails between scientists has been uncovered that indicates there has been some manipulation and/or deletion of data that did not support global warming theories, bringing into question the validity of graphs and studies that suggest the earth is warming because of human activities.

So what does this have to do with cool roofing? Can cool roofing really influence global climate? Energy Secretary Steven Chu thinks so. Some studies have shown that cool roofing can indeed help reduce urban heat islands. This may be true, but given the recent buzz noted above, is the data in those studies also suspect?

There may be some influence on urban heat islands from cool roofs, but the real and practical proven influence cool roofing has is on energy usage. Science isn’t even necessary to prove to building owners that cool roofing reduces air conditioning needs. All that a building owner needs to do is open his or her July utility bill.

Savings in summer electricity use for air conditioning is real, and even if there is some heating penalty (the idea that white roofs will prevent a building from warming up in winter), that penalty is almost always less than the benefits from reduced cooling loads.

Cool Roofing Tax Incentives

Two main Federal tax incentives exist for installation of cool roofing, but as with any Federal government program there are qualifications that need to be met.

Residential Tax Credit

At this time, single-ply membranes are not eligible for a tax credit on residential applications. However, if additional insulation is installed during roof replacement, the cost of the insulation can be claimed as a credit.

Commercial Tax Deduction

In general, tax law allows a deduction for part or all of the cost of energy efficient building property that the taxpayer places in service between December 31, 2005 and December 31, 2013. Several conditions must be met to qualify for the commercial tax deduction:

1. The building must be within the U.S. and must meet the requirements of ASHRAE Standard 90.1-2001 – Energy Standard for Buildings Except Low-Rise Residential Buildings.

2. To qualify for the maximum total combined deduction for all lighting, HVAC, hot water, and building envelope property installed, the total annual energy and power costs of the building must be reduced by at least 50 percent. A partial deduction is allowed for each separate building system. The IRS set the following target reductions in March 2008:

  • Interior lighting – 20%
  • HVAC and hot water – 20%
  • Building envelope – 10%

Cool roofing is partially qualifying if it is estimated to reduce the total annual energy and power costs by 10 percent or more. The maximum deduction amount for partially qualifying property is $0.60 per square foot of the building.

3. The Performance Rating Method (PRM) must be used to compute the percentage reduction. Calculations are based on a reference building located in the same climate zone as the taxpayer’s building and containing the new building component that has been incorporated, but is otherwise identical to the reference building. The Department of Energy maintains a list of qualified software to be used to calculate energy and power costs for certification.

4. To claim the deduction, the taxpayer must obtain a certification provided by a qualified individual. The taxpayer is not required to attach the certification to the tax return, but the taxpayer must maintain proper records to establish the entitlement. A qualified individual:

  • is not related to the taxpayer claiming the deduction;
  • is an engineer or contractor that is properly licensed as a professional engineer or contractor in the jurisdiction in which the building is located; and
  • Has represented in writing to the taxpayer that he or she has the requisite qualifications.

A certification must contain:

  • the name, address, and telephone number of the qualified individual;
  • the address of the building to which the certification applies;
  • one of five statements (as outlined by the IRS) explaining the manner in which the building envelope property satisfies energy efficiency requirements.

Why Cool Roofs Are Way Cool

By Cool Roof Rating Council

A cool roof reflects and emits the sun’s energy as light back to the sky instead of allowing it to enter the building below as heat. In many climate zones, a cool roof can substantially reduce the cooling load of the building, providing several direct benefits to the building owner and occupants:

  • Increased occupant comfort, especially during hot summer months
  • Reduced air conditioning use, resulting in energy savings typically – 10-30%1, and
  • Decreased roof maintenance costs due to longer roof life.

Cool roofs benefit the environment and public health in additional ways. As recognition of these benefits has become more widespread, cool roof requirements are appearing in building energy codes and green building programs across the nation.

Climate Change Mitigation

Cool roofs reduce greenhouse gas emissions by conserving electricity for air conditioning; less CO2 is emitted from power plants. Cool roofs also help cool the world, simply by reflecting the sun’s energy back to the atmosphere, thereby mitigating global warming. A Lawrence Berkeley National Laboratory study found that world-wide reflective roofing will produce a global cooling effect equivalent to offsetting 24 gigatons of CO2 over the lifetime of the roofs. This equates to $600 billion in savings from CO2 emissions reduction.2

Urban Heat Island Mitigation

Cities can be 2° to 8°F warmer than surrounding areas due to dark materials, including roofs, which absorb the sun’s light energy as heat during the day and release it at night as heat.3 This phenomenon prevents air from cooling down at night and results in higher temperatures being maintained longer. By immediately reflecting solar radiation back into the atmosphere and reemitting some portion of it as infrared light, cool roofs result in cooler air temperatures for urban environments during hot summer months.

Urban Heat Island Profile

Reduced Smog

Cool roofs, through mitigation of the urban heat island effect and reduction of ambient air temperatures, in turn improve air quality. Smog is created by photochemical reactions of air pollutants and these reactions increase at higher temperatures. Therefore, by reducing the air temperature, cool roofs decrease the rate of smog formation.

Public Health Benefits

Lower ambient air temperatures and the subsequent improved air quality also result in a reduction in heat-related and smog-related health issues, including heat stroke and asthma.

Peak Energy Savings and Grid Stability

Because cool roofs reduce air-conditioning use during the day’s hottest periods, the associated energy savings occur when the demand for electricity is at its peak. Therefore, cool roofs reduce stress on the energy grid during hot summer months and helps avoid shortages that can cause blackouts or brownouts. In addition, for building owners that pay for energy based on the time of use, they save energy – and more money – when it is at its most expensive.

Secondary Energy Benefits

Cool roofs directly reduce air conditioning use for buildings by reducing heat gain in the building below, but they also indirectly reduce air conditioning use in urban areas by helping lower ambient air temperatures. Cooler daytime temperatures mean that buildings and vehicles use less air conditioning and save additional energy. In turn, this results in a reduction in the CO2 emissions from electricity generating power plants.

The Cool Roof Rating Council (CRRC) is a non-profit membership organization. Formed in 1998, the CRRC maintains a credible, third-party rating system to measure and label the radiative properties of roofing materials. Please visit the CRRC at

2 Akbar, H. (2008). Global Cooling: Increasing Solar Reflectance of Urban Areas to Offset CO2. In press, Climate Change.