Buildings use one-third of all energy and two-thirds of all electricity generated. Robertson provides customers with a variety of green building options that help mitigate energy consumption and support overall green building efforts including: environmental, economic, and, health and community. As a leader in our industry, we are committed to the continuation of developing new green building opportunities and innovations for our customers.
The Green in Metal
Metal construction has green characteristics including recyclability and durability. In addition, strategically-designed metal construction projects contribute to a building’s improved energy efficiency, can reduce the amount of materials necessary for the building envelope and are often more cost effective than other non-metal construction materials.
Recyclability and Durability
Roof and wall panels, structural members and other building materials composed of steel are virtually 100% recyclable when removed, as opposed to many conventional, non-metal construction materials, which are taken to landfills. According to the American Iron and Steel Institute (AISI) and the Canadian Sheet Steel Building Institute (CSSBI), steel is the most recycled material in North America, with an annual average recycling rate of 70 percent. Furthermore, new steel made with recycled material uses as little as 26% of the amount of energy required to manufacture steel from iron and other naturally extracted materials.
Depending on the nature of the project, a Robertson metal building will contain between 25% and 60% recycled steel by weight to help with LEED credit MR 4.
In addition to recyclability, metal roofs and wall panels can reduce waste due to their unmatched durability and resistance to fire, wind and insects. AISI reports that metal roofs last between 40 – 60 years and require less maintenance than other types of roofs.
Solar Reflectivity and the Solar Reflectance Index
Solar Reflectivity (SR), or reflectance, is the ability of a material to reflect solar energy from its surface back into the atmosphere. The SR “value” is a number from 0 to 1.0. A value of 0 indicates total absorbance. ENERGY STAR requires an SR value of 0.25 or higher for steep slope (more than 2:12) roofing and SR value of .64 or higher for low slope (2:12 or less) roofing.
Solar Reflectance Index (SRI) is used to determine compliance with LEED requirements and is calculated according to ASTM E 1980 using values for reflectance and emissivity. Emissivity is a material’s ability to release absorbed energy. To meet LEED requirements, a roofing material must have an SRI value of 78 or higher for low slope (2:12 or less) roofing.
Cool Colors for Metal Roofing
Robertson offers cool paint colors for all of our metal roof panels. When used properly, considering the environment and the slope of the roof, a cool roof can reduce energy consumption, providing significant cost savings while helping to mitigate urban heat islands.
An urban heat island (UHIs) is an elevation of air temperatures in urban communities, relative to surrounding rural areas, caused when vegetation is replaced by large sections of pavement or other dark, non-reflective surfaces. Urban heat islands are believed to not only influence the temperature of the affected area but are also responsible for higher pollutants in the air.
Many of Robertson’s cool colors meet the reflectivity and emissivity performance levels required by LEED and ENERGY STAR to mitigate the cause of UHIs and energy consumption overall. Reflectivity is the deflection of solar energy from a surface. Roofs at 2:12 and greater have been proven to generate less of a heat island effect than lower-sloped roofs. Greater reflectivity abilities require less energy to cool a building.
Emissivity is the relative ability of a surface to emit heat by radiation. As with reflectivity, when a roof can effectively cool itself through radiative heat loss, it will reduce the amount of energy consumption for the building.
Insulated Metal Panels
Buildings using effective insulation systems have long-term impacts on the environment due to their ability to reduce energy consumption over an extended period. As a result, the reduction in energy used contributes to the reduction in energy costs. Robertson offers insulated metal panels that are ideal for numerous roof and wall applications, that when used as part of a strategically-designed green construction project, can improve the building’s energy efficiency, which is measured, in part, by what is known as an R-value.
The panels use a special foam insulation to provide superior R-values for greater thermal efficiency. The R-value is the unit of measurement of apparent thermal conductivity, or the resistance, of the flow of energy from warm to cold, and describes the rate that heat energy is transferred through materials. R-values are achieved by tiny air spaces that slow conductivity. Insulation with higher R-values will be more effective than those with lower R-values.
Insulated panels are ideal for temperature controlled building systems. They are thermally efficient, affordable and aesthetically pleasing. Insulated panels offered by Robertson receive excellent test results for air leakage and water penetration through panel joints and meet the weathertightness requirements of most specifications.
Robertson offers insulated panels that provide the benefit of being disassembled when they are no longer needed for a building. The disassembled metal panels can be recycled or reused to create the structure of a new metal building project. Maintaining 75% – 95% of existing walls, floors or the roof of a building provides one to two points when qualifying for LEED Certification.
For building owners and architects looking to achieve LEED Certification on an existing building, Robertson’s retrofit roofing system can help. It uses light-gauge framing in combination with our metal roofing panels. When applied over an existing roof with a specified slope, a retrofit system delivers an aesthetically pleasing effect, while improving SR values and providing water runoff solutions. In addition, if the existing roof materials remain, they won’t become waste added to landfills, with many serving as added insulation. The retrofit framing system is ideally suited for a wide-range of substrates including steel, wood or concrete. The retrofitting technique can also work for new construction as an economical and competitive alternative to prefabricated truss construction.
Long Bay® System
Robertson offers the patented Long Bay® System (LBS). Custom-engineered to accommodate expanded areas of open floor space, up to 65 feet, while allowing for uncommon flexibility in architectural design, the Long Bay® System allows building owners to use less building materials. Open web truss sub-framing provides roof support and simplifies the installation of mechanical and electrical systems. Significant overall cost savings are created by less bridging, fewer footings and the reduced number of columns needed. It also increases cost savings by reducing foundation costs and increasing the ease-of-erection. The Long Bay® System is compatible with many wall and roofing systems to increase versatility in construction design.
Whether our customer is seeking to meet LEED, Green Globes or other certification requirements or simply wanting to improve the energy performance of their building, Robertson offers solutions to reach many environmentally-friendly construction goals.