The LEED certification program is a product of the U.S. Green Building Council and is now an internationally recognized system for ensuring and measuring the sustainability of new building designs. It is setup using a combination of categories and points. A building's design and material selection must gain a set number of points in a range of categories in other to earn the distinction of being LEED certified.
Green roofs benefit builders striving for LEED certification in two ways. Not only are the roofs' energy-efficient and durable characteristics worthy of points, they also help to improve a building's overall performance, which earns additional points.
Cool metal roofs can earn points in several categories such as:
- Sustainable Sites. Gain points in regards to the reduction of urban heat island effect as well as low slope and Solar Reflective Index Requirements (SRI).
- Water Efficiency. You can use gutters, downspouts and other elements of a rain-water collection system to earn points.
- Energy & Atmosphere. Your roof's potential energy efficiency and impact on the atmosphere affect the point total.
- Materials & Resources. Choosing materials from recycled components and/or that can be recycled or reused down the road, both of which are attributes of metal roofs, is looked at favorably in the LEED certification criteria.
Metal roofs gain independent points if they are considered "cool" and you can earn additional points if you top your metal roof with plants - creating a "living" green roof. Work carefully with your metal building manufacturer if you go this route as you will have other structural details to work out in terms of water-proofing and moisture protection.
Cool Metal Roofing Is a Win-Win for LEED Certification
The overarching goal of the LEED building program is to, "...promote design and construction practices that increase profitability while reducing the negative environmental impacts of buildings and improving occupant health and well-being."
Metal roofs, and particularly those designed to increase reflectivity and emissivity meet all three of those goals.
- Increase profitability. A metal roofing increases a building's profitability on multiple fronts.
- It is an affordable and long-lasting addition to a building. Most high-quality metal roofs have up to a 40-year warranty and with proper maintenance, will not require repairs for replacements for well beyond that.
- They save a building owner significantly in terms of lifetime costs as lack of repairs or replacement saves thousands of dollars over the roof's lifetime.
- A metal roof is an attractive option for future home or commercial building buyers who know they won't have to replace the roof anytime soon.
- A LEED certified building is, in and of itself, a very attractive product in a market that continually celebrates eco-friendliness and sustainability.
- Reduce environmental impact. Here is another goal where a metal roofing system can be an advantage.
- Metal roofs are made from large quantities of recycled products, so simply selecting metal roofs - and other steel and metal building components, for that matter - is an eco-friendly choice.
- They can be recycled at the end of their lifespan. Whether the roof lasts another 60 years, or the building is torn down before that, a metal roof can be recycled, rather than added to the local landfill.
- The reflectivity and emissivity attributes of a cool metal roof not only reduce the amount of fossil fuels used to cool the building, but they also help to reduce the urban heat island effect, improving the micro-climate in urban and suburban areas around the globe.
- The longer something lasts, the less often it has to be replaced, and this inherently reduces the amount of resources used in production, not to mention the energy spent in shipping and materials transportation costs.
- Improve occupant health and well-being. Cool metal roofs are designed to improve interior comfort, which improves occupant well-being. They also contribute to better indoor air quality. The more stable interior temperatures are, the less likely humidity levels will get out of whack and the fewer chances there will be for condensation to occur.
A metal roof with a vapor barrier and adequate insulation, will ensure your building is less prone to condensation and moisture issues that lead to mold and mildew, not to mention the increased probability of moisture-related structural damage.
What to Look for in a Cool Metal Roof
First, know that not all metal roofs are cool metal roofs, and metal roofing products are not created equal. For this reason, it's important that you work with a reputable metal building supplier and/or a LEED certified contractor who is experienced with metal building materials to ensure you purchase high-quality products that meet or exceed LEED standards.
Your metal roof should:
Qualify. According to coolroofs.org, "LEED-New Construction credits roofs with a SRI value greater than or equal to 78 for low-slope roofs, and 29 for steep-slope roofs, covering at least 75% of the roof area. A lower SRI is allowed if more than 75% of the roof is covered, using a weighted formula."
Comply. Your roof design should also comply with your local building codes, taking wind speeds and/or snow load into effect so ensure it performs as expected.
A cool metal roof can take your ideas for a sustainable building and put them into more rigorous practice, helping your building gain the industry's revered title of LEED Certified".