Green News and Information
Call for uniform and enforceable green code
By: Kermit Robinson
Government at all levels has long been asking citizens to embrace energy efficiency, from promoting recycling to encouraging residents to use their cars less and use energy-efficient light bulbs. Those communities also are demanding more from their state and municipal leaders-energy-efficient buildings constructed according to enforceable, safe and sustainable building codes that complement LEED and other rating systems.
The International Green Construction Code is answering the call, and it will impact metalbased construction.
The IGCC, developed by the International Code Council in cooperation with construction industry associations representing architects, engineers, green building and illumination, is an enforceable building code designed to drive safe and sustainable construction practices. It will improve the long-term performance of new and existing commercial and residential buildings. The code complements existing voluntary rating systems by establishing new requirements for "green" construction within a jurisdiction that adopts the codes. The IGCC is coordinated with ICC's extensive family of construction codes.
Although the IGCC is not a rating system, it incorporates an innovative new concept, project electives designed to encourage and drive the construction of buildings that exceed minimum code requirements, much like rating systems do. It contains features that allow jurisdictions to customize and tailor the code to address sustainability and performance concerns at a local level.
For metal-based construction, energy-efficient design and materials feature prominently as the IGCC focuses on specific areas such as material selection, insulation and roof selection (see sidebar).
The IGCC requires 55 percent of the building materials meet either a minimum percentage of the materials to contain a minimum percent of recycled content; the materials be manufactured such that at least 30 percent can be recycled or recovered later; or use materials or bio-based materials (Sections 503). Most steel structures will likely satisfy this requirement, given their highly recycled and recyclable composition. While such a stipulation may not fundamentally change the materials used in construction, jurisdictions where the code is adopted are going to want proof that the materials being selected and later installed meet that section of the code.
When it comes to the challenge of increased insulation that many metal structures require to meet and exceed efficiency standards, the IGCC offers accommodates for eight climates zones. This piece of the code stipulates how much insulation is needed based on the temperatures and humidity levels in each zone. The insulation requirements are intended to keep better control "on the seams" to keep energy from leaking and resulting in increased efficiency.
The roof of any structure has the potential to be inefficient-allowing cool air to escape and heat to be absorbed. The IGCC provides guidelines to solve those problems by requiring the use of surfaces that are absorbent, reflectant or painted with carefully chosen colors to control heat island impact. Materials common to buildings and roads and site development will absorb and retain heat more than farmland or undeveloped land such as forests. As a result cities develop a 'heat island' that impacts the local climate. Enough heat island build-up and it takes more effort to cool buildings. Vegetative roofs can also be used to absorb heat in certain situations (see sidebar).
The IGCC will have a direct and positive impact on communities' efforts to create healthier environments. For example, it requires that builders reduce construction waste in materials and that at least 50 percent of construction phase waste materials be diverted from landfills. These standards apply to on-site construction, as well as to the manufacturing of materials. Water conservation efforts continue to be a focus of the code throughout the life of the building, as facilities managers are encouraged to use graywater for irrigation, for example. This section of the IGCC may be particularly useful in areas where water must be used strategically, such as in the Southwest.
While IGCC requires the typical commissioning, it also promotes enhanced inspection to measure energy efficiency. Those inspections are conducted at various points during the process, including before and after the building is occupied. One of the goals of commissioning is to ensure that actions such as sealing the building and HVAC systems are doing what they are designed to do-essentially serving as a check on the design. This is required before a building is given its certificate of occupancy.
Under Section 304 and the whole building life cycle assessment, the CO2 emissions may need to be assessed and documented if global warming is included as a component of the review criteria. However, this is not a mandatory requirement, but a good example of the built-in flexibility provided by the code.
The IGCC also weighs quality of life issues when considering energy efficiency, taking occupants' comfort and efficiency into consideration, for example, when it requires the presence of natural light via skylights or windows. This standard represents a shift from building codes of late, which have focused on structures that have fewer windows to keep energy from leaking out of them.
Several jurisdictions have already adopted Public Version 2.0 of the code due to its adaptability, enforceability and ability to lay a foundation for more sustainable communities. Adoptions include including Maryland, Rhode Island, and communities in Arizona, Colorado and Washington.
There will be opportunities for members of the metal design community to comment on the code in May at Code Development Hearings in Dallas and the Final Action Hearings in November 2011 in Phoenix. The final version of the IGCC is slated to roll out in early 2012.
The code's cooperating sponsors are the American Institute of Architects, ASTM International, the American Society of Heating, Refrigeration and Air Conditioning Engineers, the U.S. Green Building Council and the Illuminating Engineering Society.
Insulation
The focus of the IGCC is to increase the long term performance of structures and as part of that goal, sections such as insulation are especially critical to metal building developers.
Structures built using metal frames are susceptible to having heat flow through metal studs and joists. Because of this difference, structures often times need to place continuous insulative sheathing over the outside of the wall frame and between the metal framing pieces in order to maximize energy efficiency. The IGCC addresses this unique need for metal structures in the areas of materials selection and insulation by requiring:
Materials Selection
•No less than 55 percent of the total building materials either be used, recycled content, recyclable or bio based materials
•Requires contractors to document the origins of the materials used, as well as its recycled content
Insulation
•Requires increased insulation to mitigate heat loss of metal structures
•Varies based on the temperatures and humidity levels in each climate zone
•Roof Selection requires the use of surfaces that are absorbent, reflectant or painted with carefully chosen colors to control heat island impact
•Options for vegetative roofs to absorb heat Sections 607 and 806 of the IGCC provide more details on insulation for the building envelope.
Vegetative Roofs
Rising energy costs and the need for increased energy efficiency are two main drivers behind most high performance building efforts such as the IGCC. A third driver of equal importance is to reduce the long term impact of building construction and use on the environment. All of these drivers are also behind the development of vegetative roofing.
Vegetative roofing has the potential to reduce heating and cooling costs in addition to reducing usage of peak electricity, controls ambient air temperature and reduces drainage runoff. One of the best things about the roofs is that they can be developed with very little experience by the owner of the structure, but when it comes to creating a good structural foundation the IGCC provides the footing to make for a successful vegetative roofing project.
There are many areas of the IGCC that cover vegetative roofs and even roofing options that are specific to metal structures. Those areas covered are in the extensive and intensive vegetative roofs and metal roofs section (406.7):
•Requires the use of surfaces that are absorbent, reflectant or painted with carefully chosen colors to control heat island impact
•Not less than 75 percent of the roof surfaces of buildings located in climate zones 1 through 3, as established in the IECC, shall be in compliance with Section 404.3.1 or 404.3.2, or a combination of both methods.
•In climate zones 4 through 8, as established in the International Energy Conservation Code (IECC) the development of a new building with roof coverings in accordance with Section 404.3, shall be recognized as a project elective.
•All plantings shall be selected according their United States Department of Agriculture hardiness zone classifications and shall be capable of withstanding the climate conditions of the jurisdiction and the micro climate conditions of the building site including, but not limited to, wind, precipitation and temperature.
•Protection measures include, but are not limited to, installation of pre-grown vegetated mats or modules, tackifying agents, fiber blankets and reinforcing mesh.
Kermit Robinson is senior technical staff at the International Code Council, Washington, D.C. For more information on these sections of the IGCC, go to www.iccsafe.org/igcc and download a free copy of Public Version 2.0.
Source: Metal Construction News June 2011 Newsletter
Solar Revival: With Falling Costs, Improved Efficiency, and Fresh Designs, the Old Stalwart Photovoltaics are Again Poised to Ascend.
By: Michael Cockram
Photovoltaics, the conversion of solar radiation into electricity, reached two important milestones in 2010. First, new installations of photovoltaic (PV) modules were expected to surpass 14 gigawatts worldwide by year’s end—at least doubling the 2009 installations. Tat’s the equivalent of about 14 coal-fired plants. Also, for the first time anywhere, PVs crossed the “nuclear threshold”: energy from photovoltaics is now more cost effective for North Carolina customers than nuclear energy, according to a Duke University study.
Photons into Electrons
A basic PV module consists of two semi-conductor layers. As light energy strikes the first layer, electrons are “excited” and are captured in the second layer. The amount of energy captured is limited to a small bandwidth of the sun’s available energy. Current commercial solar cells range from 7 to 24 percent in efficiency, but given the quantity of solar radiation available, this percentage can amount to significant power.
For optimal performance a solar panel should be roughly perpendicular to the sun’s rays. Since the position of the sun changes seasonally and throughout the day, arrays are often fixed to the best average south-facing position, according to latitude. This position can be tweaked for certain demands. For example, if cooling loads are higher in the afternoon, the array can be shifted slightly toward the west to harvest more afternoon sun.
The two most common types of PV systems are crystalline silicon and thin-film modules. Crystalline cells are used in typical flat solar panel systems. The most common and efficient crystalline cells are monocrystalline, which are made from a single continuous silicon crystal. Polycrystalline cells are made from multiple crystals and have a more varied texture. They are easier to produce, making them less expensive than monocrystalline cells. All PV panels should be well ventilated since excessive heat build-up can lower the efficiency of the units.
Thin-film modules utilize very fine layers of semiconductors deposited on an electrically conductive surface. While they are cheaper than crystalline cells, they are less efficient so they require more area to generate an equivalent amount of energy. Some thin-film modules have the advantage of being light and flexible, making them a good option for building retrofits where roof loads are a concern.
PVs produce direct current (DC) so most systems require an inverter to transform the power into alternation current (AC) for use with all standard fixtures and equipment. Typical inverter losses drop efficiency by about 5 percent. Since solar panels are wired in a series, when one portion of the array gets shaded then the efficiency of all the panels in the series drops. If it’s unavoidable that one or more panels get occasional shade, then a bypass diode can be installed to keep efficiency of the other panels stable. Another option is to use micro-inverters on each panel or a portion of an array.
Design & Photovoltaics
In his lectures, architect and author Ed Mazria, FAIA, who founded the 2030 Challenge, often begins with the point that more than enough solar energy falls on the average building to power it over the course of a year. Emerging technology and lower costs are bringing this vision closer to reality. One challenge for designers has been in detailing solar components in a way that is integral to the design of the building. The image of an alien-looking solar array bolted to the roof of a structure is giving way to new design approaches that incorporate PV as an aesthetic element rather than an appliance.
Recently, several architects have featured PV in high-profile projects. Japanese architect Toyo Ito ringed the stadium for the 2009 World Games in Taiwan with an enormous snaking arc of PV panels. The 8,840 panels shade the seating areas and are expected to provide 1.6 million kilowatt hours of electricity annually. The project has apparently started a trend in emblematic solar stadium design with similar proposals for Tokyo’s 2016 Olympic and Dubai’s 2022 World Cup bids.
The firm of William McDonough + Partners used a solid PV array on the vaulted roof of the net-zero Lewis Center at Oberlin College completed in 2000. The project demonstrated that architects, balancing efficiency and design, could orient PV panels at less than optimal angles and still produce a substantial amount of power. More recently, McDonough incorporated rooftop panels and thin-film shades over the south-facing windows in the NASA Sustainability Base in Ames, California.
The endeavor was spearheaded by Steven Zornetzer, NASA at Ames associate director, who saw the project as an opportunity for the building to be a net-energy producer and a test bed for emerging technology.
“NASA is in some ways the reason that PVs are where they are today—[much of the development of photovoltaics is] due to the research for powering the early space vehicles of the 60s and 70s and Skylab,” says McDonough + Partners project manager Alastair Reilly, AIA. So, it made sense for PV to play an important role in the building.
As with other high-performance projects, the goal was to make the building as efficient as possible to reduce the amount of PVs required. According to Reilly, building loads were reduced by about 50 percent using an efficient envelope, maximizing natural ventilation, and optimizing building shape and orientation. The level roof of the building accommodates a large array of flat PV panels, and south-facing windows are shaded with horizontal building integrated PVs (BIPV), which are photovoltaic cells laminated between two sheets of glass.
Building Integrated Photovoltaics (BIPV)
Essentially, BIPV incorporates photovoltaics as an integral part of the building’s envelope, rather than a component that’s applied to a building. Still considered a niche market, BIPV is also one of the fastest growing segments in the PV industry.
Photovoltaic roofing tiles have advanced the idea of full integration of PV. The tiles are “walkable” and provide a watertight seal while they generate power. The system utilizes “touch safe” connections so that the array is linked in a series with one home run cable ready for the electrician. “There are no [electrical] tools needed,” says product developer and BIPV consultant Steve Coonen. “You can lay this roof tile down and plug it into the next one. The whole point is: a roofer can deal with it,” Coonen adds.
Another application that’s gaining ground is the use of BIPV products in the ground is the use of BIPV products in the walls and windows of buildings. Vertically oriented PVs, like those mounted horizontally, won’t yield the efficiency of a panel mounted for optimal sun angle. There are options available ranging from whole wall systems to spandrel panels. For lower Manhattan’s Whitehall Ferry Terminal renovation in 2008, Frederic Schwartz Architects used crystalline panels for opaque spandrel glass in the walls. As with Pelli Clarke Pelli’s nearby Solaire residential tower in Battery Park City, the vertical panels can gain up to 10 percent from reflected energy because they face the waters of Hudson Bay, according to Coonen.
Financing PV
With demand and production of photovoltaics increasing, the price continues to fall, placing PV installation within reach for many more consumers. “For commercial projects at the beginning of 2009 the installed cost was about $8 per watt,” says Doug Boleyn, PE, of the Oregon Energy Trust. “Nowadays we’re seeing commercial installations at around $5.50 per wall—a substantial drop in 18 months.”
Despite the trend, some consumers are waiting for PVs to become even more affordable. However, holding out may not be the best strategy. In a Scientific American podcast, groSolar CEO Jeff Wolfe makes a case for investing now: “…while the prices are declining, the government incentives are also declining, and so what you have is a race to [determine] the best time to buy solar. If we look back historically over the last four or five years, the best time to buy solar has always been the present day, because as the prices in equipment and installation decline, incentives tend to decline faster.”
Wolfe adds that payback periods for investing in a PV system can range from 5 to 15 years. However, there are growing options that allow PV use without a large initial investment. The most widely used commercial financing model in the U.S. is called a solar power purchase agreement (SPPA), where an owner makes a building or property available to a third-party solar development company that gets sole rights to any available renewable energy credits (RECs). The third-party developer can usually sell the green power however it wishes—so the owner, while helping to generate renewable energy, may actually be receiving “brown” power the grid. The owner agrees to a rate structure (usually lower than utility rates) and to a time period for the contract. The provider purchases, installs, and maintains the system, so there are no significant upfront costs to the owner.
The National Renewable Energy Laboratories (NREL) opted to use SPPAs on several buildings in their Golden, Colorado, complex. “NREL has four different solar PPAs, about 2.5 MW total,” says NREL’s Otto Van Greet, PE. “In all cases a PPA was chosen because NREL did not have access to funding to directly purchase a PV system at the time. Additionally NREL, like all government agencies, does no pay taxes and is thus unable to take advantage of tax incentives. A system owned by a tax-paying third-party (PPA) can take advantage of tax incentives.” Unfortunately, only 17 states currently accommodate PPAs for renewable energy sources.
In a similar model, several solar developers are offering to lease PV systems. Leasing is growing in popularity especially among residential customers who want to use solar, but who’d like to avoid the substantial front-end costs. In this case, the consumer pays a monthly fee that can shave up to 15 percent off their utility bills. Lease amounts increase annually at set rates, with the assumption that utility rates will increase as well.
An option adapted from Germany is the “feed-in-tariff” system. Here, utilities agree to (or are obliged to) purchase energy from owners with renewable sources such as PVs. Rates are set at an appropriate amount within the established time frame.
Some sites don’t have adequate sunlight to make a PV system viable. And there are those clients and designers who don’t want to apply PVs directly to their buildings. In these instances, owners can purchase a portion of a solar array from a community solar farm or solar collective and have a percentage of their utility bills credited accordingly.
The Role of Incentives
The U.S. federal government offers incentives only in the form of tax credits, leaving most of the incentives up to the states and individual utility companies. Since the range of incentives varies wildly place to place, stakeholders need to be well versed in what rebates, grants, and tax-breaks are available in a particular location. For example, in California there is a plethora of tax breaks and rebates, net-metering is widely available from utility companies, and regulations for power-purchasing agreements are in place. But many states have few incentives, spotty access to net-metering, and no opportunities for third-party agreements. (The North Carolina Solar Center maintains a state-by-state summary of incentives with an interactive map at the Database of State Incentives for Renewables at dsireusa.org).
In areas where there aren’t enough incentives to make PVs viable, NREL’s Van Geet points to the importance of designing buildings solar ready. “In a state like Arkansas, you’re less likely to use solar because of cheap coal-fired power and the economics of incentives aren’t good there,” He continues: “You should at least plan for PVs because it doesn’t cost anything by designing for the weight of the future PV system.” Polk Stanley Wilcox Architects designed the LEED-Platinum Heifer International for PV. “We looked at PV initially but the payback didn’t meet our goals,” relates principal Reese Rowland, AIA. “We recognized that we could prepare for a time when costs would come down.”
For residential pitched roofs, designers should add about 2 pounds per square foot. Flat commercial roofs require about 4 pounds per square foot additional capacity. NREL has a guide to making buildings solar ready that available at nrel.gov.
The International Boom
Recently, the U.S. has made significant gains in the number of PV systems installed. Growing at 30 to 40 percent a year, we’re now third in PV installations. However, that’s still behind the smaller European countries of Germany and Italy. Germany’s solar surge is fueled by generous incentives aimed at curbing greenhouse gas emissions. Also, European countries are interested in curbing dependence on Russian fossil fuel. China has become a top producer of inexpensive PV modules. Despite its enormous economy and its penchant for headline-grabbing green projects, China doesn’t rank in the top tier of PV consumers.
The potential in the U.S. is tremendous. Big box retailers and other corporations are beginning to make green flourishes with PV installations. Wal-Mart, with some 81 million square feet of roof area, has installed panels on 31 stores with another 20 to 30 slated for thin-film installations. And the much publicized Google campus has a 1.6 megawatt system that will power up to 30 percent of its facilities. However, the majority of these projects remain in states like California where the incentives are strong.
The crossing of the nuclear threshold in the Duke University study shows that PVs are viable in a state with average renewable energy incentives and moderate solar conditions. It is another bellwether that PVs, with their near universal availability, are going to play a key role in our energy future. That future was alluded to in a recent double-page ad in The New Yorker magazine that showed three lithe girls under an umbrella taking refuge from North African sun. The headline asserts: “0.3 percent of Saharan Solar Energy Could Power Europe.” This pronouncement comes not from the solar energy industry, but from a bank. The gist of the ad is that, with some smart financing, we could use the energy that’s warming the planet and transform it into renewable energy. While the answers to the climate change and our dependence on fossil fuels are more complicated than the ad implies, photovoltaics are proving to be one solution worth investing in.
Source: GreenSource magazine, January/February 2011
Metals Roofs And Renewable Energy Systems – A Lasting Combination
By: Scott Kriner, Technical Director, LEED AP, The Metal Initiative
A growing need to reduce energy consumption, waste, and CO2 emissions is clear. But the next step – how to reasonably achieve that – still needs to be addressed.
Building owners and developers face difficult challenges in this process, particularly when it comes to meeting stringent codes for energy efficiency in new and existing buildings. But a logical, easily accessible solution to this dilemma lies with renewable energy systems integrated with metal roofs.
Value
Metal has several benefits for renewable energy systems. Durability is a major one, according to Tony DeLoach, owner of WES Industries, Sarasota FL, a company that engineers, designs and installs renewable energy systems.
“Metal roofing makes complete sense for solar because of the life of the metal roof at 40, 60 or more years. There’s nothing I know of that offers the kind of warranty as a standing seam metal roof. Plus, they’re now all very attractive and come in a variety of colors. If our company owns the renewable energy system, we also look at the efficiency we can gain by mounting it on a metal roof. If we can incorporate the cost of the metal roof in the project we gain warranty and thermal benefits and are still dollars ahead,” DeLoach says.
Metal roofing also allows the roof to be installed to a pitch that takes full advantage of the angle of the sun in a given location. This ability to customize the pitch maximizes a solar system’s output on a direct mount.
Costs
Building owners have several ways to fund a renewable energy system. The four main ways are to pay cash, obtain a bank loan, tap a line of credit or lease the system through vehicles such as a power purchase agreement (PPA). In a PPA, the developer or other third party entity funds the renewable system and sells the energy to the building owner at a reduced rate.
According to Gregg Cassarini, Business Development Manager for Conergy, a solar energy company focused on large scale solar development projects, commercial projects generally average an 8 to 10 percent internal rate of return, but can be higher depending on applicable incentive and cost structures.
“You need to look at all of the cost parameters, including installation and operating expenses, revenues, and borrowing costs to see how much you’ll get back over a certain time horizon. Some states have government subsidies for system owners, which can be the host or a third party. Those incentives along with the electricity savings will provide the rate of return on the investment,” he said.
Conergy is based in Hamburg, Germany, and Cassarini is based in its U.S. headquarters in Denver. The company also is a wholesale distributor of solar products.
Other alternatives can trim the upfront cost of the system, according to Tom Price, Executive Director, of San Francisco-based Black Rock Solar. His organization is the nation’s largest non-profit installer of renewable energy. It obtains most of its funding from public utility rebates and donations from foundations.
His company works with organizations that can’t afford the systems on their own and recently helped an elementary school in rural Nevada that was forced to lay off six of its 40 teachers due budget cuts.
“The school administrators thought they couldn’t afford a renewable energy system even though it’s what they needed to reduce costs. But we figured out how to have it paid almost entirely by rebates from utilities and raised the balance through donations. After two months they saved enough money to hire back two teachers,” Price said.
“The exciting thing about renewable energy systems is that they’re not complicated they’re just unfamiliar to a lot of people. Any competent roofer can learn the basics in a day,” Price said.
Bright Future
The experts all agree that the use of renewable energy systems will continue to increase. And as long as the sun is in motion this market will grow and metal roofs will continue to be the choice for optimum long-term performance.
Source: www.designandbuildwithmetal.com
Opportunities Opening for Metal
By: Brendan O'Neill
The leaking pipe causing the oil spill in the Gulf of Mexico has been effectively capped at the time of publication of this issue of Metal Construction News. This is of course good news for residents in the Gulf region after nearly three months of continually bad news. During this time, alternative energy experts have been cropping up everywhere you look, from television to newspapers and magazines and numerous online outlets.
The consensus seems to be that this recent oil tragedy is just the latest—and possibly largest—reminder that we need alternative sources of energy in place now, not five, 10 or 20 years from now. One of the possibilities is wind energy, illustrated on every news program with giant wind turbines grouped in expansive wind farms. But that requires great resources—chief among them, land and money.
The other popular alternative is solar power. This is where metal construction comes in. Over the years it has become obvious that metal roofing is the perfect place for photovoltaics. Large solar panels, flexible films and even PV paint are all in use on metal roofs across the country, and with a relatively small capital investment, these quick-and-easy installations are recouping their costs quicker than ever before. As solar power grows in popularity, so too will metal construction components.
In one example, a 7,500-square-foot solar panel array installed on the headquarters of a company in New Jersey consisted of 392 panels for a 81.5 kW system. The $700,000 investment generated 124,034 kWh of energy in the first full year of operation, ending in June 2010. The system generates 305 kWh of electricity per day, representing approximately 99 percent of the company's current power needs.
To date, the solar panels have prevented 227,011 pounds of emissions of CO2, NOx and SO2 into the atmosphere—more than an average passenger car emits during a 20 year period. Also of note, the company has recouped 75 percent of the cost of the installation already, thanks to utility savings and various state and federal programs.
While this is a large PV system, the positive benefits and savings are on par (proportionally) with arrays of other sizes.
The integration of such energy systems into metal construction components like roofs, the expansion into other areas such as wall panels, and the development of new technologies including PV paints and coatings, should all help the metal construction industry propel itself into the future as the best, most effective construction method for an increasingly green and sustainable society.
Source: Metal Construction News magazine, August 2010
With Prepainted Metal, Products Last Longer And The Environment Stays Greener
By Jim Dockey, National Coil Coating Association
While there are many benefits to using prepainted metal in terms of cost savings and production line efficiencies, many manufacturers choose coil coated metal for its durability. Prepainted metal provides products with increased performance and corrosion protection, helping coatings last longer, look better and end up in landfills less often. That’s a win for us all.
In the metal construction industry, prepainted metal is the de facto standard for metal roof and wall panel systems specified with a painted finish. And beyond metal cladding systems, prepainted metal is routinely used for HVAC units, truck trailers, bleachers, road signs, fuel tanks, exterior doors, window frames and metal furniture. Coil coated metal is used for these products because it provides the utmost protection from the elements.
Even when the same type of coating is used, prepainted metal parts outperform post-painted parts due to the application process. When the coil coating process is used, the metal is uniformly cleaned, primed, pretreated and painted as a flat surface on both sides before it is formed into parts. A primer coat is often used and prevents the undercutting of paint and enhances corrosion resistance, durability of the product, and overall quality. Furthermore, with prepainting, the primer and paint are tightly bonded to the metal and are often applied to both sides of the metal. Post-painted parts generally do not include the primer and are not coated as evenly as prepainted coils.
During the design phase, and then regularly thereafter during regular production, coil coated parts are tested for corrosion-resistance with standardized testing using salt, chemical sprays, and/or water immersion. They are also examined for weathering resistance with accelerated ultraviolet and other environmental exposure tests. Test relating to stain resistance, welding capability, and resistance to abrasion are also performed depending on final application.
Continuous testing and adjustments made during the coating process ensure high-quality output. The paint thickness, curing temperature, and production line speed are monitored and controlled throughout the process. And then before leaving the production line, physical characteristics including gloss, color, hardness, adhesion, and resistance to cracking and marring are tested. This high level of control is not possible with post painting processes.
For products with exposed cut-edges, prepainted coatings outperform post painted coatings significantly. In field tests, prepainted metal louvers with exposed cut edges were compared to the same type of louvers with three different post paint applications (electrocoat, powder finish and spray finish). The louvers were exposed to the same elements in Florida for five years. The prepainted cut-edge far outlasted all three types of the postpainted edges. Visit www.coilcoatinginstitute.com/tutorials/# for details on the independent field study on cut edge.
All in all, manufacturers using prepainted metal will find superior coating durability, increased corrosion resistance and consistent color, texture and thickness in their finished products. For more information about converting to prepainted metal, visit: www.coilcoatinginstitute.org.
Source: www.designandbuildwithmetal.com
The Ecological Benefits of Metal Roofing
Metal roofing has a long, successful history worldwide. It's proven track record spans all types of projects-new construction and remodeling for commercial, industrial, and residential buildings. With today's heightened interest in and demand for ecologically sound building materials, metal roofing rises to the top as the product of choice. The Metal Construction Association ardently supports metal roofing's inclusion in all lists of environmentally friendly or "green" roofing materials
The ecological benefits of metal roofing include:
Sustainability
Metal roofing's durability can virtually eliminate the need to use future raw materials to produce roofing. Metal roofing is unaffected by the hot-cold/wet-dry weather cycles that break down other materials. Other roofing materials, however, are heavily affected by weather extremes. In addition, metal roofing is known for its ability to hold up against other weather forces including windstorms, hail, ice, and snow. No other roofing material has greater ability to withstand a wider range of weather conditions than metal. There are many handmade metal roofs still in existence that date back to the 1800s. Commercially produced metal roofing systems have been available since about 1910; numerous profiles and types have been produced since then, and there are examples of these roofs across the country. While some metal roofs are quite lasting and durable, with exposed metallic surfaces, modern technology also has introduced quality paint systems that beautify metal roofing and are warranted for as long as 50 years. Metal roofs can be repainted for additional life, if necessary. As America's homes and other structures age, it is imperative that we choose long-term building products; metal is the product of choice for sustainability.
Recycled content
As consumers, many of us are careful to collect our recyclable materials and turn them in for collection. In reality, though, we are offered very few consumer products where we can "close the loop" by purchasing products that are high in recycled content. Metal roofing, however, offers that option to consumers by allowing them to choose a significant building product on the basis of its recycled content. Most metal roofs have recycled content ranging from 25% to 95%. This is in stark contrast to conventional roofing shingles, which have much shorter lives and use oil-based products as their primary raw material. The recycled content of metal roofing has been a compelling reason for several state and local entities, such as solid waste districts and departments of natural resources, to include metal roofing on their list of "green" and recycled content products.
Recyclability
While metal roofing is known for its extremely long life, it does have the added benefit of being 100% recyclable if it is ever removed in the future, perhaps as part of a building renovation. Whereas other old roofing materials are disposed of by the ton in landfills across the country each year, the steel, aluminum, and copper used in metal roofing can be recycled in their entirety, potentially even becoming another metal roof.
Low Weight
Depending on the product chosen, metal roofing has a weight that is 1/3 to as little as 1/8 the weight of conventional roofing shingles! In comparison to heavy tile and slate roofing, the weight of metal roofing is virtually miniscule. This low weight serves several valuable purposes. First, it puts less weight load on a structure. This helps extend the life of buildings and it also provides invaluable protection against roof cave-in threat in the event of seismic activity. However, with retrofit applications, many metal roofs can be installed over the old roofing material. This prevents the need to remove the old roof and fill up valuable landfill space. Each year, about 20 billion pounds of old composition roofing shingles are dumped into U.S. landfills. Metal roofing is the way to avoid this degradation of the environment. Additionally, metal's low weight and high strength present an ideal way to cover and encapsulate existing asbestos roofing shingles rather than create a health risk as a result of removing the asbestos and putting it in a landfill. State EPA offices support this practice of asbestos shingle encapsulation.
Product Safety
Metal roofing and the finishes used on it are inert, safe materials that do not pose a health risk. Furthermore, metal roofing is noncombustible, which provides additional fire protection for homes. Of course, one roofing material that has turned out to be very dangerous is asbestos shingle roofing. Asbestos was used extensively many years ago and now that we have realized the health hazards it poses, we're spending many millions of dollars each year to get rid of it. This worry does not exist with metal. Also, many consumers with chemical sensitivities are turning to metal roofing and finding that it does have the allergy problems associated with other roofing materials. Today's commercially produced metal roofing systems are carefully tested on an ongoing basis for performance, wind resistance, fire resistance, and hail resistance. They are listed with various building codes and entities including Underwriters Laboratories; International Congress of Building Officials; Dade County, Florida; Southern Building Code Congress International; and others.
Energy Efficiency
Metal roofing is rapidly gaining acceptance as a very energy efficient material. Property owners have reported energy savings of as high as 20% and even more after installing metal roofing. The reflectivity and subsequent energy efficiency of metal roofing has been confirmed in studies done by Florida Solar Energy Center, Florida Power and Light, Oak Ridge National Laboratory, and other independent organizations. Ongoing studies are being conducted to continually substantiate and quantify the energy efficiency of metal roofing. Many available metal roofs are being documented to meet Energy Star requirements. Prepainted metal roofing can display solar reflectance of at least 65% and thermal emittance of 80%. This can have a tremendous impact on energy usage by reducing air conditioning costs and the smog and pollution that are created by the production of that energy. Additionally, the low thermal mass of metal roofing means that it dissipates heat very quickly once the sun goes behind a cloud or sets for the day. Other roofing materials have greater thermal mass and will continue to radiate captured heat into the structures beneath them even when the sun is not shining.
Conclusion
In light of the above benefits, the Metal Construction Association strongly encourages metal roofing's consideration and inclusion on lists of "green" building products. Many state "green" programs have already included metal roofing products on their published lists. Roofing is a major component of any structure, and it is a component where the product chosen can have a dramatic effect on the building's life cycle and energy costs. Metal roofing's many benefits, including sustainability, recycled content, recyclability, low weight, and energy efficiency, far outweigh virtually all other roof systems from an ecological standpoint.
Source: The Metal Construction Association, Sustainable Design: www.metalconstruction.org
Can You Claim Points on the LEED Regional Materials Credit?
It's time to clarify what qualifies and what does not qualify under the LEED-2009 program's Regional Materials Credit 5 in the Materials and Resources (MR) section. One to two points are available for registered building products involved in new construction, schools or core and shell applications that meet the requirements of MR Credit 5. Those requirements pertaining to metal building envelope components state:
"Use building materials or product that have been extracted, harvested or recovered, as well as manufactured within 500 miles of the project site for a minimum of 10% or 20%, based on cost, of the total materials value. If only a fraction of a product or material is extracted, harvested, or recovered and manufactured locally, then only that percentage (by weight) must contribute to the regional value."
In the time since this language first appeared in the LEED program, there has been confusion about how to define or interpret the meaning of "extracted, harvested, or recovered, as well as manufactured" as it relates to a particular product. This confusion has resulted in a marketplace where product producers have different interpretations, resulting in some producers claiming these points and others feeling that the points do not apply.
In order to obtain clarification on this controversial credit, MCA contacted the USGBC Technical Customer Service staff familiar with this language. After much correspondence with technical persons at the USGBC, we reached the following collective response:
"In the case of recycled metal, the harvesting location is considered to be the plant from which the metal is made available for resale. This location must be located within the 500-mile radius of the project site. For example, since steel is made up of so many recycled components, the original point of salvage is often impossible to identify.
However, in the case of mined ores and minerals, making sure the mined materials are in fact harvested from within the 500-mile radius would be required. If both the source of the metal (recycled or ore) and "the melt shop" are within the stipulated radius, that would certainly meet the intent and requirements of the credit.
For recycled materials, the more applicable term from the credit language is the point of "recovery." If the "raw material" for the product that is being used on the LEED Project is recycled material that was 'recovered' from the scrap yard, the scrap yard should be used as the point of extraction/harvest/recovery (i.e., origin) for the raw material.
In the case of steel or aluminum, when a re-melting of scrap is part of the manufacturing process, if the "melt shop" for the metal is more than 500 miles from the project site, then that material will not be eligible for this credit. All of the extracting, harvesting, recovering and manufacturing of the product must be within a 500-mile radius."
Based on these responses from the USGBC, it appears that a metal roof or wall panel provided to a LEED registered building project could not be eligible to contribute to the 1-2 points in MR Credit 5 Regional Materials unless the mined ore or minerals, or scrap used as raw materials; the mill where the raw materials are refined into a final flat sheet product; and the manufacturing facilities that process the flat sheet product into a final metal roof or wall panel sold to a customer are all located within a 500-mile radius of the building project site.
Source: "MCA News" Summer 2009
International Green Construction Code Available From ICC
Washington, DC - The International Code Council® (ICC®) announces that it has finalized the first green construction code for commercial buildings. The International Green Construction Code (IGCC) is coordinated with the existing International Codes, making it more easily enforceable, useable and adoptable. The IGCC development process included diverse experts from government, industry and advocacy organizations to produce a consensus IGCC Public Version 1.0 through a public and participatory series of meetings.
ICC says that the IGCC was designed to respond to the need expressed by jurisdictions who struggle with developing their own green code without the experts that have advised them on developing the rest of their codes.
IGCC Public Version 1.0, available on March 15, 2010, is the latest in a long list of sustainable design codes and provisions the Code Council has been publishing for years.
In addition to creating a new regulatory baseline for jurisdictions, the IGCC will allow additional customization at the jurisdictional level, and be compatible with voluntary rating systems (e.g., LEED, Green Globes) According to ICC, the IGCC also offers many unique features and benefits in that it:
• Will offer the most comprehensive and effective code for alternative water sources such as graywater, rainwater and reclaimed water. This is important, not just for regions struggling with limited water supplies, but to offset possible water shortages in the future, even in areas where this has never been an issue;
• Encompasses the latest alternative energy technologies such as wind turbines, geothermal heating, solar energy, energy recovery, and management and control systems;
• Is the first and only construction code that establishes code requirements for a minimum level of sustainability in commercial buildings;
• Is based on the same clear, easy-to-use sequence that makes the I-Codes® the most accepted code adoption platform in the U.S. This, combined with the extensive support and level of devotion the Code Council offers its users, is why they’re the leader in codes and related products, and is a key reason for why more and more countries around the world are choosing to adopt ICC Codes over others;
• Offers the flexibility jurisdictions need in order to customize the code based on local factors such as flood areas, greenfield sites, light pollution, and many others.
Jay Peters, Executive Director of the ICC’s Plumbing, Mechanical and Fuel Gas Group indicates that understanding sustainable design and the codes that support it are not a passing phase, but rather instead, part of an evolution that will result in the integration of green construction practices into standard construction practices. “It will soon become second nature to implement greener plumbing, mechanical and other energy- and resource-saving practices,” Peters said.
For the same reasons why ICC codes are adopted in more jurisdictions than any other, building departments and key building and sustainability stakeholders are applauding ICC’s development of this unique tool. Visit www.iccsafe.org/igcc for more information and to download a free copy of the IGCC.
About The International Code Council
The International Code Council (ICC) publishes building safety, energy efficiency and fire prevention codes that are used in the construction of residential and commercial buildings. Most U.S. cities, counties and states choose the I-Codes based on their outstanding quality. The ICC’s Plumbing, Mechanical and Fuel Gas (PMG) Group is devoted exclusively to providing PMG products and support to jurisdictions and construction industry professionals across the country and around the globe, with one or more PMG code adopted in 49 states. The over 200 products and related services were developed specifically by and for plumbing and mechanical professionals. Contact the PMG Group for additional information at 1-888-ICC-SAFE, x4PMG, PMGResourceCenter@iccsafe.org, or visit www.iccsafe.org.
Source: www.designandbuildwithmetal.com
States Starting to Require Architects and Contractors to Design and Construct Public Buildings to Achieve LEED Silver Certification
By Angela Stephens, Stites & Harbison, PLLC
While many local jurisdictions and cities across the country have started passing regulations which implement and require sustainable design and construction practices, relatively few states have taken steps to mandate that certain public buildings achieve certain levels of LEED® Certification.
Eighteen states (Arizona, California, Connecticut, Hawaii, Illinois, Indiana, Kentucky, Massachusetts, Maryland, New Jersey, New Mexico, Nevada, Rhode Island, South Carolina, South Dakota, Utah, Virginia, and Washington) have adopted laws and regulations mandating that the construction of public buildings achieve LEED Silver Certification. Although the majority of States do not yet require that public buildings be designed and constructed to achieve a LEED Silver Certification, many of these States encourage their agencies to use green building practices or use LEED as a guideline.
The Kentucky law is illustrative of those states that have enacted a LEED requirement on public buildings. Kentucky requires that, after July 1, 2009, all public buildings (for which fifty percent (50%) or more of the total capital cost is paid by the Commonwealth of Kentucky) shall be designed and constructed in accordance with Kentucky’s new High Performance Building Regulations.
Under Kentucky’s new regulations, all public buildings (as defined above) worth $25 million or more in budget “shall be designed, built, and submitted for certification to achieve a rating of Silver Level or higher” using LEED 2009. Public buildings between $5 million and $25 million shall be designed, built, and submitted for certification to achieve a rating of LEED Certified or higher. Additionally, public buildings greater than $5 million shall achieve a minimum of 7 points under the LEED Energy and Atmosphere Credit 1, Optimize Energy Performance. Public buildings between $600,000 and $5 million in budget shall be designed and built using the LEED rating system as guidance.
There are two exceptions to the new regulations. The first exception applies when a public building fails to achieve the LEED rating due to the sole failure to receive a point for Material and Resource Credit 7 regarding certified wood. Under this first exception, the building will be deemed to meet the LEED rating required, if the project used wood products certified under the American Tree Farm System or the Sustainable Forestry Initiative.
Under the second exception, a building which is required to meet the high performance building standards may be granted an exemption if there is an “extraordinary undue burden on the agency if project compliance is required.” Factors that will be considered in determining if such an extraordinary undue burden exists include whether (1) the cost of compliance exceeds a building’s life cycle cost savings, (2) compliance increases costs beyond the funding capacity for the project, (3) compliance compromises the historic nature of a building, (4) compliance will violate any laws, (5) the unique nature of a project makes it impractical, or (6) the building will use another high performance building program such as Energy Star or Green Globes.
In addition to the requirements mentioned above, all public buildings (as defined above) shall be designed and constructed so that they are capable of being rated as Energy Star buildings. However, unlike the requirements discussed above, an exemption cannot be granted from this requirement.
For more information about these regulations or other green initiatives which may impact your business, please contact Angela Stephens at astephens@stites.com or at 502-681-0388.
About the Author: Stites & Harbison, PLLC has a Green Law Practice Group which is devoted to the unique legal issues associated with green initiatives and new regulations addressing environmental stewardship and sustainability. The Green Law Group is comprised of attorneys including construction attorneys, business and finance attorneys, tax attorneys, and environmental attorneys. Within this group, 10 attorneys are LEED Accredited Professionals (APs), and one attorney is a LEED Green Associate (GA). LEED AP and GA attorneys have demonstrated a thorough understanding of green building practices and principles and have the tested ability to apply the LEED Rating System standards to designing and building projects. For more information visit www.stites.com.
Source: Design Cost Data November/December 2009
Zero Energy Building Initiatives
By Scott Kriner, Green Metal Consulting
The DOE estimates that over the next twenty years 40% of the commercial building market will be built. By 2030 we will build an additional 40 billion square feet of commercial building space. The Energy Information Administration estimates that 60% of our nation’s electricity growth over the next twenty years will be related to commercial building usage.
The federal government recognized these alarming statistics and legislated a goal for all commercial buildings to become zero net energy structures by the year 2050. That legislation was part of the Energy Independence and Security Act of 2007. Congress created the Zero Net Energy Commercial Buildings Initiative (CBI) as part of that legislation. The CBI was officially launched by the Department of Energy on August 5, 2008. Its goal is “to develop and disseminate technologies, practices, and policies for establishment of zero net energy commercial buildings.”
Currently there are nine buildings that are operating at zero energy today, according to the DOE. These are verified buildings where the utility bills and operations are being closely monitored. Some of these buildings are completely off the grid, and some are sharing the grid.
The CBI is charged with a goal of demonstrating marketable zero net energy commercial buildings as early as 2025. Their milestones include .achieving zero net energy buildings in the new commercial building sector by 2030, in 50% of all commercial building stock by 2040, and in all commercial buildings by 2050. A tall order indeed.
To achieve the goal of the CBI, several alliances and partnerships have been created by the federal government. These include the Commercial Building Energy Alliances, the Commercial Building Partnerships, the National Laboratory Collaborative on Building Technology, and the High Performance Green Building Partnership Consortia.
Funding for the program has remained strong, with additional resources provided in the American Recovery and Reinvestment Act of 2009. In fact, in October of 2009 the DOE awarded a contract to form the Zero Energy Commercial Buildings Consortium as another partnership supporting the CBI. The Consortium is designed to coordinate the public and private involvement with the DOE’s work to develop and identify technologies that would help to achieve zero net energy buildings.
The Zero Energy Commercial Buildings Consortium brings together a diverse group of commercial building stakeholders to help DOE accelerate innovation, technology development and market transformation. The National Association of State Energy Officials acts as the steering committee for the Consortium. Currently the Consortium members total over 250. The members include building products manufacturers, utilities, energy providers, trade associations, engineering firms, laboratories, research organizations, federal agencies and departments and universities.
The group is planning and assisting in the implementation of a strategy to change the way commercial buildings use energy. The Consortium will identify promising new technologies and effective public policies. Some of these developments will result in demonstrations and pilot programs. The involvement of the private sector allows the Consortium to design, initiate and evaluate programs aimed at deployment of proven energy-saving technologies.
All aspects of construction and operation of commercial buildings are being considered. This includes development of more energy efficient building envelope assemblies and systems. A zero energy building, by definition, is one that generates as much electricity as it consumes. The first step is to find ways to significantly lower the use of energy through conservation efforts and improvements in efficiency. The second step is to design methods for generating energy on-site in many cases. When selecting a solar power, solar thermal or wind energy system for on-site usage, it is important to consider and compare the service life of those systems to the platform being used. A metal roof with more than 40 years of expected service life is an excellent platform for photovoltaic systems whose service life is approximately 25 years. In addition, new dynamic envelope technologies are being evaluated with metal roofing to dramatically reduce heat gain/loss while utilizing heat energy that is contained in the roof assembly.
The metal construction industry is involved in the Zero Energy Commercial Building Consortium. Just look at the list of the 250 members and you will find many companies and organizations involved in metal construction. We need to remain a part of this solution to our nation’s energy needs.
Scott Kriner, MCA's Technical Director, is the president and founder of Green Metal Consulting Inc. He is a LEED Accredited Professional who began his career in the metal construction industry in 1981. His company is a member of the U.S. Green Building Council, the California Association of Building Energy Consultants and the Residential Energy Services Network (RESNET). Scott can be reached by email at skriner1@verizon.net, or by phone at (610) 966-2430. You can also visit him on the web at www.greenmetalconsulting.com.
Source: www.designandbuildwithmetal.com