RIMA International Celebrates 40 Years

In 1978 Don Roy (Roy & Son’s), Pat Mascari (Infra) and Robert Dittemore (Superior) met in a hotel restaurant in Los Angeles to discuss forming an industry trade association for their products. It was decided to name the association the Reflective Insulation Manufacturers Association (RIMA).

These original three members were invited to Washington, DC, in 1979 to participate in the DOE/FTC hearings on insulation products. They were joined by RIMA member Raymond Urias of A.I.M. and together represented reflectives at the event. At the completion of the hearings, the Federal Trade Commission published what was to become known as the “R-Value Rule”. This rule still governs the way all insulation products and radiant barriers are packaged, tested, and sold today.

RIMA went international in 2007 when the first international gathering took place in Paris, France.  There were 11 different countries represented at the event where guests were able to share how reflectives were being used and tested, how they were incorporated into building codes and the various hurdles being encountered.  The event was such a success, the International Reflective Insulation Manufacturers Conference (I-RIM Conference) was born and is now held every two years in various locations around the world.

RIMA-I members are still very active in ASTM, ASHRAE, ICC and IBC participating in code development/changes and participating in meetings and code hearings throughout the year.  In 2018 the Advanced Building Code Coalition (ABCC – www.advancedbuildingcodecoalition.org) was created to allow companies that are not reflective manufacturers to support and take a more active role in the codes teaming together to have a stronger presence and make a bigger impact within the building codes.

For more information, visit www.rimainternational.org.

Cool Roofs Are Still a Hot Topic

Figure 1. ASHRAE Climate Zone Map. Cool roofs are currently required in Zones 1-3 only.

The overwhelming consensus is that cool roofs are a clear top choice in warm climates, but what about cooler ones?

Studies and decades of real-world experience clearly show that cool roofs are net energy savers and improve thermal comfort in Climate Zones 1-3. The model codes (ASHRAE and the I-codes) already include requirements for some new and replacement roofs to be highly reflective in these areas.

But what about “cool, northern” climates like Climate Zone 4? Shown in yellow on the ASHRAE Climate Zone Map in Figure 1, Zone 4 stretches from the Mid-Atlantic across the southern Appalachian states to the southern Midwest.

There are a number of myths that have led to a notion that the dividing line between “warm” and “cool” lies between Climate Zone 3 and Zone 4. In “cool” climates where heating degree days outnumber cooling degree days, the traditional thinking goes, the cost of extra heating demand caused by cool roofs in winter would offset the cooling energy cost savings in summer. Despite decades of market experience and a vast body of research supporting the net benefits of cool roofs in Climate Zone 4, this line of thinking has been an obstacle to cool roof policy in the United States. Let’s dispel some of those myths by looking at a few facts.

  • Winter heating penalties associated with cool roofs in cool climates are vastly overstated. Higher insulation levels in Climate Zone 4 do not offset the benefits of cool roofs. Research over the last couple of year (field and modeling), some of which I’ve cited in this article, show that the so-called “winter heating penalty” is much smaller than many

    Figure 2. Peak demand is remarkably similar across climates. Source: Dr. Jim Hoff. “Reducing Peak Energy Demand: A Hidden Benefit of Cool Roofs.”

    thought. Specifically, a field and modeling study done at Princeton University’s campus (in Climate Zone 4) compared cool and black membranes over roofs with insulation levels up to R-48. The studies show that cool roofs reduce heat inflow in summer but have the same heat loss in winter as black surfaced roofs over the same level of insulation.
    Another study evaluated the impact of reflective roofs on new and older vintage commercial buildings in cold locations including Anchorage, Milwaukee, Montreal, and Toronto. All cities in the study are located in climates zones north of Climate Zone 4 and experience longer, colder winters than cities in Climate Zone 4. The study finds that “Cool roofs for the simulated buildings resulted in annual energy expenditure savings in all cold climates.” The study also identified peak energy savings in addition to the base energy efficiency gains.

  • Figure 3. Projected temperature change for mid-century (left) and end-of-century (right) in the United States under higher (top) and lower (bottom) emissions scenarios. The brackets on the thermometers represent the likely range of model projections, though lower or higher outcomes are possible. Source: USGCRP (2009).

    Heating and cooling degree days are not a good way to determine the appropriateness of cool roofs. Heating/cooling degree days indicate the intensity of the annual heating/cooling demand in a location, as a function of how far the outdoor air temperature is below/above a “comfortable” temperature and how much of the year is spent below/above that threshold. These metrics paint a misleading picture because they are based on outdoor air temperature and do not account for the sun’s ability to heat buildings or on the heat generated by human activity in the building. To illustrate this point, consider a cool sunny day during which the outdoor temperature approaches, but never exceeds, the comfort threshold (meaning zero cooling degree days). The sun may nevertheless heat the building enough throughout the day to require air conditioning by late afternoon, and cooling degree days would then underestimate actual cooling energy use.

Conversely, the sun’s heat on a cold sunny day may cause heating degree days

Figure 4. Energy cost increases and total damages from rising heat. Source: Solomon Hsiang et al. “Estimating economic damage from Climate Change in the U.S.” Science, June 2017.

to overstate the true demand for heating energy. This suggests that reflective roofs can save energy over the course of a year even if heating degree days exceed cooling degree days. Or take heat from building occupancy and activity — many commercial buildings run space cooling year-round, thus negating the concept of a heating penalty altogether. The effect of occupancy will only increase as building standards require more insulation and fewer air gaps. The comparison of heating and cooling degree days, though simple and logical-sounding, is actually a very unreliable rule of thumb for the assessing the suitability of reflective roofs.

  • Peak energy demand reduction is a huge, but often overlooked, benefit of cool roofs in all climate zones. Reflective roofs save the most energy during peak energy demand periods, like hot summer afternoons. Field studies indicate a peak demand savings of 15 percent to 30 percent resulting from reflective roofs (see http://www.coolrooftoolkit.org/wp-content/uploads/2012/07/CEE_FL-Cool-Roof.pdf).

Unfortunately, most energy savings calculators exclude peak demand, thus painting only a partial picture of the energy savings opportunity of cool roofs. Peak reductions are more than just an energy saver. Most utilities charge a peak demand fee to non-residential customers based on their maximum demand in a given period of time. This fee can be more than half the bill for some customers. Peak

Figure 5. Summers in New England could soon feel like summers in South Carolina. Source: Union of Concerned Scientists. “The Changing Northeast Climate,” 2006.

demand is also different from “base” cooling demand because it is not driven by climate. The graph in Figure 3 compares base and peak cooling demand for all U.S. climate zones and finds that peak demand requirements in Minneapolis are the same as they are in Phoenix.

  • “Cool” climates in the United States are starting to feel a lot hotter. Scientists predict an average increase in temperatures of 4-6 degrees Fahrenheit in the United States over the next 30 years or so. But as the maps in Figures 4 and 5 show, the amount of warming and its economic impact will be most acutely experienced in parts of the United States covered by Climate Zones 1 through 4.

It won’t just be hot areas getting hotter. An analysis by Union of Concerned Scientists forecast that, under a high but realistic emissions scenario, summers in New York City (the northernmost city in Climate Zone 4) could feel like South Carolina. Recently, the school district in Eau Claire, Wisconsin committed to replacing its black membrane roofs with white ones to help reduce temperatures during their increasingly hot summers. So, even if one still believes that Climate Zone 4 is too cool for cool roofs now, it certainly won’t be for long.

Are You Meeting Thermal Insulation Code Requirements?

Photo 1. Conditions such as this, in which the fastener plates melt the snow, visually demonstrate the heat loss that is a known entity to roof installers and knowledgeable roofing professionals.

You may have overheard conversations such as this:

New Building Owner: “You promised energy conservation and savings.”

Mechanical Engineer: “We sized the mechanical unit based on the code required effective thermal value.”

New Building Owner: “But why are my cost 30 percent above your estimates and I am needing to run my units constantly and they still barely maintain a comfortable environment?”

Mechanical Engineer: “We have checked all the set points and systems and they are all working, albeit with a bit of laboring. We don’t know why there is not enough heat.”

New Building Owner: “Well, someone is going to have to pay for this!”

Scenarios and liability questions like this are being repeated across the northern North American continent, and to mechanical engineers, architects and owners, the cause is a mystery. Perhaps they should have talked to seasoned roofing professionals and consultants. They could’ve told them that many mechanically attached roofs, incorrectly promoted and sold as energy-saving systems, were actually energy pigs. One only needed to walk a mechanically attached roof with a few inches of snow on it to see the heat loss occurring. It doesn’t take scientific studies and long-winded scenarios to prove this — just get up on the roof and see it. (See Photo 1.)

Photo 2. When a light dusting of snow blew off this 2 million-square-foot facility in central Illinois, every single mechanical fastener and insulation joint could be identified by the ice visible at their locations. This roof needed to be replaced due to condensation issues several years after installation at a cost of more than $10 million.

I spoke on this topic back in 2007 at the RCI Cool Roofing Symposium. I always like being a soothsayer, and several recent studies are demonstrating and attempting to quantify this energy loss that most roofers could tell you was there.

For years the NRCA suggested a loss of thermal value of 7 percent to 15 percent through the joints in a single-layer insulation application and through mechanical fasteners used to secure the insulation. (The NRCA has since removed this figure and suggests that professionals be consulted to determine thermal heat loss.) The NRCA recommended a cover board to reduce this effect. This was at a time when roof covers were predominantly BUR, modified bitumen or adhered single plies. The upsurge in mechanically attached single-ply membranes, brought on by low-cost installation and the promise of energy savings, changed the game. No one was asking, if there could be a loss of 7-15 percent when mechanically attaching insulation, what could the effective R-value loss be when we install thousands of fasteners and plates 12 inches on center (or less) down a membrane lap seam? Gee, haven’t we seen that before?

Code Requirements

The code and standard bodies — ICC, IECC, ASHRAE — have been repeatedly raising required thermal insulation values over the past decade in an attempt to conserve energy; that is their intent. They listened to astute designers and

Photo 3.This is close-up of the roof shown in Photo 2. Heat loss through the screws and fastener plates and through joints in the single layer of insulation melted the snow. The water froze when the temperatures dropped and the ice was revealed when a light wind pillowed the membrane and the remaining snow blew away.

prescribed two layers of insulation, and then again to determine the minimum R-value and not allow averages. The intent is clear. The required R-value per ASHRAE zone is to be achieved.

Their goals were laudable, but not all roof systems achieved the in-place R-values required. So, this article is in part an attempt to educate code officials and explain the need for a change.

Words can explain the phenomenon of thermal loss, but photos are worth a thousand words, and since my editor has told me that I cannot have a 4,000-word article, I leave it to the photos to do the talking. (See Photos 2, 3 and 4.)

Scientific Studies

In their Buildings 2016 article titled “Three-Dimensional Heat Transfer Analysis of Metal Fasteners in Roofing Systems,” Singh, Gulati, Srinivasan and Bhandari (Singh) studied the effect of heat transfer through thermal bridging (mechanical fasteners) in various roof assembly scenarios.

Their study exposes a shortfall in many standards that have as their goal a reduction in energy loss through building envelope systems through prescriptive approaches. For roofing assemblies, standards prescribe a minimum R-value, but they do not take into consideration the heat loss that happens though metal fasteners. There are no guidelines or recommendations in regards to thermal loss, including the loss of heat through roof system fasteners. It’s actually ignored.

Figure A: The effect of mechanical fasteners below the roof cover in mechanically attached roofs is not negligible as considered by general standards. As can be seen here for systems 1A and 1 B, in which mechanical fasteners are used in the lap seams of the roof cover (systems 3A and 3B have the fasteners below a layer of insulation), the actual thermal value loss caused by mechanical fasteners can be as high as 48 percent, as seen in system 1A with a high density of mechanical fasteners. As the mechanical fastener density decreases (1B), the heat loss also decreases. Thus, a correlation appears to exist in which heat loss due to thermal bridging is proportional to the fastener density.

The results of the Singh study, as seen in the graph (Figure A), show that the effects of thermal shorts, e.g., mechanical fasteners used to secure the roof cover, is not negligible. In fact, thermal shorts can result in a loss of 48 percent of the effective value. Read that again! The thermal value of the roof insulation layer on which the mechanical engineer has in part sized the mechanical equipment — and which the owner is counting on for significant energy savings — could be about half of what was assumed. Add in gaps and voids, and the loss in the effective R-value could top 50 percent. What that means is that to achieve the code required R-30, say in Chicago, mechanically fastened roof systems need to have R-45 in the design to meet the effective code required R-value. This last sentence is for the code bodies — are you listening?

The value of this study cannot be underestimated, as thousands of buildings have been constructed since its publication that would not meet an effective R-value check in a commissioning study.

Changing the Code

The energy inefficiency of mechanically attached roof systems in ASHRAE zones 4 and above has been known to roofing crews for decades. Now, with the requisite scientific studies completed, the codes need to be revised to reflect the inherent thermal loss through mechanical fasteners. Additionally, studies from Oak Ridge National Laboratory highlight the energy increase required with inherent air changes below the membrane, confirming the need for air/vapor barriers on the deck on mechanically attached roof assemblies. (See “The Energy Penalty Associated with the Use of Mechanically Attached Roofing Systems,” by Pallin, Kehrer and Desjarlais.)

Photo 4: Heat loss also occurs through adhered roofs when the insulation is mechanically attached.

As a starting point for code groups and officials, I suggest the following code revisions:

  1. State that if a mechanically attached roof cover is being used that the prescribed thermal R-value shall be increased by 50 percent.
  2. State that if a mechanically attached roof cover is being used that an air barrier below the insulation must be used and that it shall be fully adhered to penetrations and roof perimeters.

Closing Thoughts

The goal of energy conservation is a laudable one. The American Institute of Architects’ goal of zero-energy building by 2030 will never be met until real-world empirical information can be presented at code hearings. (For those of you who do not attend code hearings or know the process, information is usually disseminated in two-minute sound bites without documentation.) This lack of information sharing is a travesty and has resulted in numerous code changes that have been detrimental to the goal of energy savings. Time has come for a new way of thinking.

Efficient and Effective Construction Through Building Codes

This fire station roof assembly includes thermally efficient cross-ventilated non-structural composite insulation manufactured by Atlas Roofing and installed by Utah Tile & Roofing.   Photos: Atlas Roofing Corp

This fire station roof assembly includes thermally efficient cross-ventilated non-structural composite insulation manufactured by Atlas Roofing and installed by Utah Tile & Roofing. Photos: Atlas Roofing Corp

In a world where the bottom line is a critical concern in any construction project, conscientious design and roofing professionals look at the lifetime costs of a building instead of just the short-term construction outlay. Choices made during a building’s initial design and construction have long-term influence on the lifetime of its operation and maintenance. With so many building products and options available, building codes take on a vital role in guiding decisions about building quality, safety, and energy performance. These trusted benchmarks, compiled with input from a broad range of stakeholders, are designed to ensure that the best technologies, materials, and methods are used in construction.

Building Energy Codes 101

Model building energy codes are revised every three years to incorporate the latest research and ensure that new and existing buildings benefit from the methods and products that will produce the most value and safety over time. The International Energy Conservation Code (IECC) and ASHRAE set standards tailored to specific climate zones and include options to provide flexibility in choosing the methods and materials best suited to each project’s needs while nevertheless meeting the requirements. Without regular, incremental improvements to these codes, new buildings would be dated even before their construction begins.

Indeed, while some building features are straightforward to replace and upgrade over time, some of the most vital elements of building performance need to be “designed in” at the outset. Codes are designed to lock in savings during initial construction or major renovations to promote cost-effective design and construction practices. For example, roof replacement projects provide an opportunity to cost-effectively improve the overall energy efficiency performance of buildings.

Energy-efficient design strategies are helpful to all building owners, including government and municipal projects built with taxpayer funding. Pictured here is Fire Station #108 in Brighton, Utah. Photos: Atlas Roofing Corp.

One of the major benefits of building code updates in recent years is the focus on energy efficiency and resiliency. The Insurance Institute for Business and Home Safety writes that, “Over the centuries, building codes have evolved from regulations stemming from tragic experiences to standards designed to prevent them.” With the ongoing effects of climate change, buildings are subjected to extremes of weather and temperature that challenge the performance of their systems. Most structures built over the previous century were not designed or constructed with energy efficiency in mind and suffer from poor insulation and dramatic thermal loss. Buildings account for over 40 percent of America’s total energy consumption, 74 percent of our electricity, and cause 40 percent of our greenhouse emissions. Implementing best practices for sustainable design and utilizing highly efficient building materials like insulation could save billions of dollars a year and improve the reliability of the electrical grid systems.

Energy-Efficient Roofing

A report prepared in 2009 by Bayer MaterialScience (now Covestro), “Energy and Environmental Impact Reduction Opportunities for Existing Buildings with Low-Slope Roofs,” determined that going from an R-12 insulation level (i.e., the average R-value of roofs on older buildings) to R-30 would pay for itself in energy savings in just 12 years with an average reduction in building energy use of 7 percent. Better roof insulation also saves money on equipment, since buildings with weaker envelopes require larger and costlier HVAC systems and future upgrades to HVAC equipment that is smaller and less expensive will always be limited by this constraint.

These savings are not only confined to new construction. In renovations, the removal and replacement of a roof membrane offers the best and most cost-effective opportunity to improve a building’s thermal envelope and better position that building for energy-efficiency upgrades down the road.

Energy Efficiency in Government Buildings

While these strategies are helpful to all building owners, they are especially important for government projects built with an increasingly tight supply of taxpayer dollars. Here is another place where the building codes provide a major assist. For federal commercial and multi-family high-rise residential buildings where the design process began after Nov. 6, 2016, agencies are required to design buildings to meet ASHRAE 90.1-2013 and, if life-cycle cost-effective, achieve energy consumption levels that are at least 30 percent below the levels of the ASHRAE 90.1-2013 baseline building. These savings are calculated by looking at the building envelope and energy consuming systems normally specified by ASHRAE 90.1 (such as space heating, space cooling, ventilation, service water heating, and lighting but not receptacle and process loads not covered by 90.1).

Photos: Atlas Roofing Corp.

Changes in the 2013 edition of ASHRAE 90.1 clarify the insulation requirements of various low-slope re-roofing activities. New definitions of “roof covering” (the topmost component of the roof assembly intended for weather resistance, fire classification, or appearance) and “roof recovering” (the process of installing an additional roof covering over an existing roof covering without removing the existing roof covering) were added and the exceptions to the R-value requirement for roof replacements were clarified to include only “roof recovering” and the “removal and replacement of a roof covering where there is existing insulation integral to or below the roof deck.” In all other instances, when a roof membrane is removed and replaced, the insulation must be brought up to current R-value requirements, which range from R-20 to R-35, depending on climate zone. In addition, the prescriptive R-value requirements for low-slope roofs under 90.1-2013, as compared to previous version (90.1-2010), are higher. For instance, in populous climate zones 4 and 5 the R-values for these roofs increased from R-20 to R-30.

The Department of Energy is preparing to start a rulemaking process to update the federal building energy standard baseline to the 90.1-2016 Standard, which will provide about an 8 percent improvement in energy cost savings compared to 90.1-2013. However, no changes were made to the R-values for low-slope roofs. Managers of federal buildings are working to comply with updated directives that impact new construction and building alterations, including:

  • “Guiding Principles for Federal Leadership in High Performance and Sustainable Buildings”
  • GSA PBS-P100 “Facilities Standards for the Public Buildings Service”
  • DOD’s Unified Facilities Criteria (UFC).

The instructions in these publications coupled with Executive Order 13693, issued on March 15, 2015, and “Guiding Principles for Sustainable Federal Buildings,” require new and existing federal buildings to adopt improved energy efficiency and “green building” attributes. New buildings are expected to “employ strategies that minimize energy usage” and existing ones must “seek to achieve optimal energy efficiency.” These directives require:

  • Regular benchmarking and reporting of building annual energy use intensity.
  • Annual 2.5 percent improvement in energy use intensity every year through the end of 2015.
  • All new buildings be designed to achieve net-zero energy use beginning in 2020.

Good Practice in Action

At the end of the day, the success of building codes in producing the cost-savings, weather-resiliency, and energy efficiency is determined by how they are adopted and enforced locally. If the most current codes were universally adopted and enforced,

Photos: Atlas Roofing Corp.

there would be no competitive advantage to inferior building construction practices. Incremental upgrades would provide a steady stream of work that would increase competitiveness for building professionals and suppliers. Updated job skills would increase market value for construction professionals and enable innovation in the construction sector and increased market share for innovative products and processes that would improve economies of scale and lower their cost differential.

Building codes provide a comprehensive and reliable standard that contribute to local economies and improve building performance. Knowledge of code requirements help designers and contractors deliver more value to their clients. Finally, a bit more of an investment during design and construction can yield significant savings in building operation and tangible benefits to the environment and economy of areas that adopt higher building standards.

Cool Roofs in Northern Climates Provide More Bang for the Buck Than We Thought

Electricity demand in Washington, D.C., plotted against daily high temperature. Source: Weather Underground, PJM Interconnection (PJME).

(Figure 1) Electricity demand in Washington, D.C., plotted against daily high temperature. Source: Weather Underground, PJM Interconnection (PJME).

The energy savings from cool, reflective, roofs have long made them the go-to roof choice in warmer and temperate climates here in the United States. Both ASHRAE and the International Energy Conservation Code have included roof surface reflectivity requirements for a number of years. About half of all new flat roofs installed in the country are highly reflective and in some product categories white options outsell dark ones by a substantial margin. It is hard to argue with the notion that, where it is warm, the roofs should be white. While the building-level impacts of cool roofs in cool climates has been covered in the past, very little has been written about the broader economic benefits of cooler buildings and cities. When we include the economic impacts of factors like improved health, air quality, and energy savings, the case for cool roofs in cool climates looks even better.

The Benefits of Cool Roofs Go Way Beyond the Building

The building-level impacts of cool roofs are a central part of the discussion about whether they should be used in cold climates. However, it is also important to recognize the substantial co-benefits that come from installing cool roofs in terms of healthier and more comfortable people, improved productivity, better air quality, and increased economic prosperity. While the economic benefits of cool roofs are substantial, they may not always be fully included in a building owner’s roof buying decision.

How much cooler could our cities become if we added more reflective roofs? In a comprehensive review on this topic, Santamouris 2012 found that when a global increase of the city’s albedo is considered, the expected mean decrease of the average ambient temperature is close to 0.5°F (0.3°C) per 0.1 increase in reflectivity, while the corresponding average decrease of the peak ambient temperature is close to 1.6°F (0.9°C). The cooling impact of reflective roofs in certain neighborhoods could be significantly better, though. A study of Chicago by Notre Dame University found that installing reflective roofs cooled city surfaces by around 3.5 to 5.5°F (2-3°C), but surfaces in the downtown core cooled by 12.5 to 14.5°F (7-8°C).

Cool Cities Are Energy Savers

We have started to better understand and quantify the impact in cities that are able to get a degree or two of cooling. The most obvious benefit is that cooler cities demand less energy on hot days. The graph in Figure 1 plots electricity demand in

Lowering the temperature of cities can bring a multitude of benefits. Source: Global Cool Cities Alliance.

(Figure 2) Lowering the temperature of cities can bring a multitude of benefits. Source: Global Cool Cities Alliance.

Washington, D.C., against the maximum temperature every day for 5 years (2010–2015). The graph’s shape looks very similar to plots from other cities with high penetrations of air conditioning units. Demand for electricity climbs rapidly above about 80°F. When the maximum temperature is 90°F, the city requires 21 percent more electricity, on average, than on 80°F days. At 95°F, demand has spiked by nearly 40 percent over the 80°F baseline. Charges for peak electricity demand are a major expense for commercial and industrial building operators and, in seventeen states, for homeowners as well. Further, peaking demand is often met by less efficient, more expensive, and dirtier power plants that worsen air quality. At worst, peak demand can cause productivity-killing service interruptions or brownouts.

Cooler Cities Are Healthier Places

Heat is a potent but silent killer. On average, heat kills more people than any other natural disaster, and heat-related deaths tend to be underreported. In 2015, Scientific American reported that 9 out of the 10 deadliest heat events in history have occurred since 2000 and have led to nearly 130,000 deaths. Cities on dangerously hot days experience 7 percent to 14 percent spikes in mortality from all causes.

Heat stress and stroke are only the tip of the pyramid of heat health impacts. Heat puts significant additional stress on people already suffering from diseases of the heart, lungs, kidneys, and/or diabetes. A recent study finds that every 1.5°F increase in temperatures will kill 5.4 more people per 100,000 people every year.

Installing cool roofs or vegetation can lead to a meaningful reduction in heat deaths by making the daytime weather conditions more tolerable. There are a number of studies estimating the impact of increasing urban reflectivity and vegetative cover on weather conditions. Kalkstein 2012 and Vanos 2013 looked at past heat waves in 4 U.S. cities and modeled the impact of increasing reflectivity by 0.1 (the estimated equivalent of switching about 25 percent of roofs from dark to light colors) and vegetative cover by 10 percent. Though the sample sizes are too small to draw sweeping conclusions, the studies found that cities making these modest changes could shift weather into less dangerous conditions and reduce mortality by 6 percent to 7 percent.

Cooler Cities Are Engines of Economic Growth

The health, air quality, and energy benefits of modest increases in urban roof reflectivity could generate billions of dollars of

An infrared scan of Sacramento, Calif., shows the range of surface temperatures in the area. Source: Lawrence Berkeley National Laboratories.

(Figure 3) An infrared scan of Sacramento, Calif., shows the range of surface temperatures in the area. Source: Lawrence Berkeley National Laboratories.

economic prosperity for our cities. A study of 1,700 cities published in the Journal Nature Climate Change found that changing only 20 percent of a city’s roofs and half of its pavement to cool options could save up to 12 times what they cost to install and maintain, and reduce air temperatures by about 1.5°F (0.8°C). For the average city, such an outcome would generate over a $1 billion in net economic benefits. Best of all, adding cool roofs to between 20 and 30 percent of urban buildings is a very realistic target if existing urban heat island mitigation policy best practices are adopted.

Cool Roof Performance in Cold Climates: In Brief

As positive as cool roofs are for cities in cool climates, they first have to be a high-performing choice for the building itself. What do we know about net energy savings in cool climates with higher heating load? This question was the subject of “There is Evidence Cool Roofs Provide Benefits to Buildings in Climate Zones 4-8” in the November/December 2016 issue of Roofing that summarized the newest science and field studies that show that reflective roofs provide net energy benefits and favorable heat flux impacts on roofs in cold climates. In short, the newest research from Columbia, Princeton and others demonstrates that the size of the “winter heating penalty” is significantly less than many had thought and shows net reductions in annual energy use when cool roofs are used, even with roof insulation levels as high as R48.

Real Cool Roofs in Cold Climates: The Target Survey

It is not just the science that supports the use of reflective roofs in cold climates. The strong and steady growth of cool roofing in northern markets over the last decade or two is also a good indication that reflective roofs are a high-performance option in those areas. For almost 20 years, Target Corporation has installed reflective PVC membranes on nearly all of its stores in the

Studies estimate that modest increases in urban roof reflectivity could generate billions of dollars of economic prosperity for cities. Pictured here is the roof on the Cricket Club in Toronto. Photo: Steve Pataki

Studies estimate that modest increases in urban roof reflectivity could generate billions of dollars of economic prosperity for cities. Pictured here is the roof on the Cricket Club in Toronto. Photo: Steve Pataki

United States and Canada. The membranes are usually installed over a steel deck with no vapor retarder. Target and manufacturer Sika Corporation undertook a field study of 26 roofs on randomly chosen stores located in ASHRAE Climate Zones 4-6 including Connecticut, Illinois, Massachusetts, Michigan, Minnesota, New York, Washington, and Wisconsin. The roofs were 10-14 years old at the time of the survey. None of the 51 total roof sample cuts were made across these roofs showed signs of condensation damage. A more detailed accounting of the study by representatives of Target Corporation and Sika Sarnafil published in Building Enclosure includes this important paragraph from authors Michael Fenner, Michael DiPietro and Stanley Graveline:

“Specific operational and other costs are confidential information and cannot be disclosed. However, it can be stated unequivocally that although the magnitude varies, Target has experienced net energy savings from the use of cool roofs in all but the most extreme climates. Although the savings in northern states are clearly less than those achieved in southern locations, experience over approximately two decades has validated the ongoing use of cool roofs across the entire real estate portfolio. Even in climates with lengthy heating seasons, overall cooling costs exceed heating costs in Target’s facilities.”

It is increasingly clear that installing cool roofs is the definition of “doing well by doing good.” Even in cold areas, a properly built roof system with a reflective surface is a high-performance option that delivers value for building owners while making hugely positive contributions to the neighborhoods and cities they occupy.

Court Ruling Allows Continued Development of Public Health and Safety Standards

The United States District Court for the District of Columbia (Hon. Tanya S. Chutkan) has issued a ruling that will support federal, state and local governments’ efforts to support public health and safety through the use of voluntary consensus codes and standards. The court granted a motion for summary judgment filed by a number of standard development organizations (SDOs), including the National Fire Protection Association (NFPA), ASTM International and ASHRAE. The court’s ruling permanently enjoins Public.Resource.org from its previous systematic infringement of numerous SDO copyrighted codes and standards. The ruling vindicates the longstanding public-private partnership pursuant to which government entities may, if they choose, incorporate by reference high quality safety codes and standards.

“We are pleased with the court’s decision, which recognizes the importance of a time-tested process that serves governments and individuals well and is vital to public health and safety,” says Jim Pauley, president of NFPA.

The history of not-for-profit SDOs developing voluntary consensus standards goes back more than a century. Governments, businesses, and individuals across the country rely on a variety of works, from product specifications and installation methods to safety codes and standards.  SDOs, not governmental agencies, underwrite the costs of developing standards.
 
“The court’s ruling means federal, state and local agencies can continue to rely on not-for-profit SDOs to develop voluntary consensus standards at a high level of excellence and at minimal cost to government,” says Kathie Morgan, president, ASTM International.

SDOs pay for the standard development process and invest in new standards with the money earned selling and licensing their copyrighted works.  This model allows SDOs to remain independent of special interests and to develop up-to-date standards.  It also allows the U.S. government, and governments at all levels, the freedom to decide whether to incorporate these standards by reference without a drain on their resources.
 
“We and many other SDOs already provide free online access to many standards as part of our commitment to safety,” says Timothy G. Wentz, ASHRAE president. “And, preventing the infringement of copyrighted material will allow not-for-profit SDOs to continue meeting the needs of the people and jurisdictions we serve.”
 
For more information about this issue visit the website.

NIBS Releases New Building Information Modeling Guideline

Following a year-long development process, the National Institute of Building Sciences has released its new guideline to help building owners utilize building information modeling (BIM). The “National BIM Guide for Owners (NBGO)” provides building owners with an approach, from their own profession’s standpoint, to create and fulfill BIM requirements for a typical project. Unveiled during the kickoff of Building Innovation 2017, the Guide is now available free online.

The National Institute of Building Sciences, with the support of ASHRAE, Building Owners and Managers Association International (BOMA) and financial support from the U.S. Department of Defense – Defense Health Agency, compiled a balanced, integrated team that has worked for the past year to craft the NBGO. The team developed the guide under the premise that BIM, in and of itself, is not the end but rather the means to a number of potentially valuable project delivery outcomes for the building owner.

The 36-page NBGO addresses three broad areas the owner should understand in order to work effectively with the Project BIM Team: process; infrastructure and standards; and execution.
 
The guide provides building owners with a documented process and procedure for their design teams to follow to produce a standard set of BIM documents during the design and construction of the facility, and for maintenance and operations of the facility upon handoff. Establishing the criteria, specifications and expectations in the design and construction process will help owners capture the full value of investing in BIM, while providing a uniform approach for institutional and commercial building owners to achieve consistent BIM requirements for their facilities.

Thanks go to the NBGO team, including the team’s chair, Dan Chancey, RPA, senior vice president, Asset Management, Cushman & Wakefield, Commercial Advisors; Ernie Conrad, PE, BOMA fellow, representing BOMA International; Carrie Sturts Dossick, PhD, PE, associate professor and executive director, Center for Education and Research in Construction, University of Washington; Craig R. Dubler, PhD, DBIA, manager, Facility Asset Management, Penn State University; Johnny Fortune, CDT, LEED AP, BIM/IT director, Bullock Tice Associates; M. Dennis Knight, PE, FASHRAE, founder & CEO, Whole Building Systems LLC, representing ASHRAE; and John I. Messner, PhD, Charles and Elinor Matts Professor of Architectural Engineering, director, Computer Integrated Construction Research Program, Penn State University.

The new guideline, which is based on a number of foreign, federal, state and local BIM guides that already exist, is geared to a generic facility with uniform requirements for use by a variety of government, institutional and commercial building owners. It references a range of documents and practices, including those contained within the National BIM Standard-United States.

The next step will be to submit the NBGO for publication as an industry standard. Download the NBGO.

There Is Evidence Cool Roofs Provide Benefits to Buildings in Climate Zones 4 through 8

FIGURE 1: Reflective roof requirements in ASHRAE 90.1 and IECC only apply in Climate Zones 1 through 3, shown here on the ASHRAE Climate Zone Map. SOURCE: U.S. Department of Energy

FIGURE 1: Reflective roof requirements in ASHRAE 90.1 and IECC only apply in Climate Zones 1 through 3, shown here on the ASHRAE Climate Zone Map. SOURCE: U.S. Department of Energy

Reflective roofs are a tried and true way to improve building energy efficiency and comfort, generate net energy savings and help mitigate summer urban heat islands. Reflective roofs work by reflecting solar energy off the roof surface, rather than absorbing the energy as heat that can be transmitted into the building and surrounding community.

The simple act of switching from a dark to a light-colored roof surface has a number of benefits. Buildings protected by these types of roofs require less energy to cool and help building owners and residents save money. Cool roofs on buildings without air conditioning can save lives during heat waves by lowering indoor temperatures. Cooler city air is safer to breathe and less polluted, which makes cities more livable and less vulnerable during heat waves. Increasing the reflectivity of urban surfaces can also offset the warming effect of green- house gases already in the atmosphere and help us address the challenges of climate change. Taken together, these benefits are worth billions of dollars to the growing number of people that live and work in U.S. cities.

The energy-savings case for cool roofs in warm climates is clear. Widely adopted model building-code systems, ASHRAE and the IECC, address roof reflectivity. ASHRAE 90.1-1999 added a credit for highly reflective roofs with IECC allowing compliance via ASHRAE in 2003. ASHRAE 90.1-2010 added reflectivity requirements for new and replacement commercial roofs in Climate Zones 1 through 3. IECC added the same requirements in its 2012 version. (Figure 1 shows the ASHRAE climate zone map for the U.S.)

There is, however, an ongoing debate about whether cool roofs deliver net energy benefits in northern climates that experience cold winters and warm to hot summers (Climate Zones 4 through 8). Do reflective roofs remain beneficial as the cold weather season kicks in? The same properties that allow reflective roofs to keep buildings cooler in the summer may also cause them to make buildings colder in the winter. Theoretically, buildings with cool roofs could require more energy to reach a comfortable temperature in winter—a consequence known as the “winter heating penalty.” Furthermore, building codes tend to require more roof insulation in colder climates than warmer climates, potentially reducing the energy-efficiency benefits of roof surface reflectivity.

FIGURE 2A: Annual energy-cost savings ($1 per 100 square meters) from cool roofs on newly constructed, code-compliant buildings with all-electric HVAC. SOURCE: Energy and Buildings

FIGURE 2A: Annual energy-cost savings ($1 per 100 square meters) from cool roofs on newly constructed, code-compliant buildings with all-electric HVAC.
SOURCE: Energy and Buildings

The “winter heating penalty” and the impact of insulation are considerations when installing reflective roofs in some cold climates, but their negative effects are often greatly exaggerated. The sun is generally at a lower angle and days are shorter in winter months than summer months. In fact, in northern locations winter solar irradiance is only 20 to 35 percent of what is experienced in summer months, which means the sun has a reduced impact on roof surface temperature during the winter. Heating loads and expenditures are typically more pronounced in evenings, whereas the benefit of a darker roof in winter is mostly realized during daylight hours. Many commercial buildings require space cooling all year because of human activity or equipment usage, thereby negating the little—if any—heating benefit achieved by a dark roof.

Two new studies, along with decades of real-world examples from the marketplace, indicate that reflective roofs are an effective net energy (and money) saver even in our coldest cities.

SNOW’S IMPACT

In a study recently published in Energy and Buildings, researchers from Concordia University in Montreal evaluated the energy-consumption impact of adding cool roofs to a number of retail and commercial buildings in Anchorage, Alaska; Milwaukee; Montreal; and Toronto. The researchers looked at older, less insulated building prototypes, as well as newer buildings built with code-compliant levels of insulation. Unlike earlier work evaluating the impact of roof reflectivity on building energy consumption in cold climates, this new analysis also accounted for the impact of snow on the roof during winter months.

FIGURE 2B: Annual energy-cost savings ($1 per 100 square meters) from cool roofs installed on older buildings with all- electric HVAC. SOURCE: Energy and Buildings

FIGURE 2B: Annual energy-cost savings ($1 per 100 square meters) from cool roofs installed on older buildings with all- electric HVAC.
SOURCE: Energy and Buildings

Snow has two impacts on the roof that are relevant to understanding the true impact of roof surface reflectivity on energy consumption. First, snow helps insulate the roof. As a porous medium with high air content, snow conducts less heat than soil. This effect generally increases with snow density and thickness. Second, snow is white and, therefore, reflective. At a thickness of about 4 inches, snow will turn even a dark roof into a highly reflective surface (approximately 0.6 to 0.9 solar reflectance).

When snow is factored in, the benefits of cool roofs in cold climates be- come much clearer. Figure 2a shows the net energy savings and peak electricity reduction with and without snow for cool roofs installed on newly constructed, code-compliant buildings, assuming all-electric HVAC. Figure 2b shows savings from cool roofs installed on existing, older vintage buildings. The paper, available from the journal Energy and Buildings also includes results with gas HVAC systems.

INSULATION’S EFFECTS

Another argument often heard against reflective roofing in cold climates is that buildings in northern climates tend to have higher levels of roof insulation that reduce or negate the energy-savings impact of roof surface color. A new field study and model analysis of black and white roof membranes over various levels of insulation by the City University of New York and Princeton University and Princeton Plasma Physics Lab, the latter two of Princeton, N.J., clearly rebuts the “insulation versus reflectivity” tradeoff.

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You Can Influence Codes and Standards

As associate executive director of the Washington, D.C.-based EPDM Roofing Association (ERA), I focus a great deal of my time and energy on the codes and standards that regulate or guide the roofing business. In the current environment, driven by constant upgrades in technology, as well as the need to save energy, these codes—and the standards that often inform them—seem to be undergoing steady revision. Believe it or not—and the word “geek” does come to mind—I find participating in this process extremely interesting. In fact, following and sometimes influencing emerging codes and standards is among the most important responsibilities of my job.

I’ll be the first to admit that a detailed review of a standards manual is probably not anyone’s idea of exciting reading. But given the importance of codes and standards to the construction industry, we ignore them at our own risk.

For a start, what’s the difference between a code and a standard? Ask enough people in the roofing industry and you will get a variety of answers. But generally, codes are the “top-tier” documents, providing a set of rules that specify the minimum acceptable level of safety for manufactured, fabricated or constructed objects. They frequently have been enacted into local laws or ordinances and noncompliance can result in legal action. Standards, on the other hand, establish engineering or technical requirements for products, practices, methods or operations. They literally provide the nuts and bolts of meeting code requirements. If codes tell you what you have to do, standards tell you how to do it. Frequently, standards—especially “voluntary consensus standards”—are the precursors for what becomes law years down the road.

ERA has represented the manufacturers of EPDM roofing for more than a decade. Through the years, we have learned the importance of interfacing with standard-setting and regulatory bodies. One of our first, and most important, learning experiences was working with the Northeast and mid-Atlantic states when they issued regulations designed to achieve federally mandated air-quality standards. (See the article in Roofing’s September/October 2014 issue, page 58.) The initial regulations, which lowered the amount of VOCs in many roofing products, were based on those used in southern California and incorporated provisions that were effective in the climactic and market conditions of that state. But states in the affected areas, from Virginia to Maine, confronted a situation where the new regulations threatened to bring the roofing industry to a sudden halt. In some instances, no adhesives and sealants were available to meet the new standards. And the new products, when they became available, would need to be effective in very cold climates totally unlike those on the West Coast.

ERA worked with officials throughout the impacted areas, helping to create “phase-in” schedules that would give industry enough time to develop products to meet the new standards. In state after state, the local regulators welcomed our input. Our point-of-view was based on a deep understanding of the business needs of our industry. Just as important, we understood the science behind the proposed regulations and could work with the regulatory bodies to ensure the air-quality needs and the needs of the roofing industry were met.

This experience has informed our ongoing approach to code-setting and regulatory bodies. Since our work with the states setting VOC standards, we have invested staff time and resources to stay current with and even ahead of proposals that would impact our members and their customers. We have testified before the South Coast Air Quality Management District in California on its proposal to limit VOCs. ERA has organized an ad-hoc coalition to successfully oppose an unnecessarily stringent proposal to require reflective roofs in the Denver area. And our organization is currently providing input to Atlanta-based ASHRAE’s efforts to clarify its regulation regarding air leakage. This issue—of great importance to the roofing industry—relates to other work being done in ASHRAE working groups and subcommittees on thermal bridging, as well as the definition of walls and wall assemblies. ASHRAE has convened an “Air Leakage Work Group” whose charge is to review the pertinent sections of Standard 90.1 and make recommendations for revising it. ERA staff will be present at this group’s meetings and will once again provide input based on the expertise of our members.

When I work with code-setting and regulatory groups, I am reminded of that very familiar saying, “It’s not whether you win or lose, it’s how you play the game.” Based on our work at ERA, I’d like to revise that. Your skill at “playing the game” will definitely influence whether you win or lose. Our experience tells us that staying involved with regulatory groups and providing them with input based on firm science and field experience leads to a winning outcome for the roofing business.

Standard for the Design of High-Performance Green Buildings Is Open for Public Review

Changes to the purpose and scope that reflect advances in green buildings over the last 10 years are proposed for the high performance building standard from ASHRAE, the International Code Council (ICC), the U.S. Green Building Council (USGBC) and the Illuminating Engineering Society (IES).

ASHRAE/IES/USGBC/ICC Standard 189.1, Standard for the Design of High-Performance Green Buildings, contains minimum requirements for the siting, design and construction of high-performance green buildings in support of reducing building energy use, resource consumption and other environmental impacts while maintaining acceptable indoor environments.

Among them is addenda o, which proposes revisions to the existing purpose and scope of the standard to clarify its intended purposes and application, and to better reflect the revisions to the standard that are being considered by the committee.

Committee chair Andrew Persily notes that the current title, purpose and scope were approved in 2006 and that much has taken place in the world of green buildings in the past 10 years.

Under addenda o, the purpose of the standard has been rewritten to focus on goals vs. strategies. For example, rather than energy efficiency, the goal of reduced building emissions is proposed for inclusion in the purpose.

A new section of the purpose speaks to the alignment of Standard 189.1 with the International Green Construction Code (IgCC), noting specifically that the standard is intended to serve as the technical basis of mandatory buildings codes and regulations for high-performance buildings.

Standard 189.1 currently is a compliance option of the 2015 IgCC, published by the International Code Council, ASTM and the American Institute of Architects. The standard will serve as the technical content for the IgCC beginning in 2018.

Other addenda open for public review until May 8, 2016 are:

  • Addendum i reorganizes the roof heat island mitigation section and adds new provisions for vegetated terrace and roofing systems relative to plant selection, growing medium, roof membrane protection and clearances. In addition, provisions for the operation and maintenance of vegetated roofs are proposed for addition to Section 10.
  • Addendum n clarifies footnote b to Table 7.5.2A. This footnote provides a method to adjust the percent reduction for buildings with unregulated energy cost exceeding 35 percent of the total energy cost. This addendum clarifies that the adjustment is to be made on the basis of energy cost, not energy use.
  • Addendum p proposes to add requirements for water bottle filling stations, which are intended to improve water efficiency and sanitation of public drinking water and to reduce the environmental effects of plastic bottles.
  • Addendum r lowers the ductwork pressure testing threshold to include 3-inch pressure class ducts, which are common upstream of variable air volume (VAV) boxes.
  • Addendum t adds new requirements for reverse osmosis and onsite reclaimed water systems in order to reduce the likelihood of excessive water use because of poor design of water treatment and filter system.
  • Addendum u adds new requirements for water softeners to reduce water consumption given the impact of the design and efficiency of these systems on water discharge water rates.

Open for public review from April 8 until May 23, 2016 are:

  • Addendum q modifies Chapters 5, 7, 8 and 11, as well as Appendices A and E, to reflect the addition of Climate Zone 0 in ANSI/ASHRAE Standard 169-2013, Climatic Data for Building Design Standards.
  • Addendum s removes the performance option for water use and moves the prescriptive option into the mandatory section.