For the owners of the Headquarter Honda facility in Clermont, Florida, building a landmark LEED? Platinum project meant incorporating nearly every type of environmental rooftop solution including reflective membrane, day-lighting, PV, solar thermal, and a vegetative roof system. Completed in January 2010, the building has a 126 kW solar PV system and a 6,000-square-foot extensive, irrigated greenroof.

As is common in construction, there were several hurdles the design and construction team had to solve. While installations using PV and vegetative roofing in a totally integrated system can create a cooler environment in which solar panels can function, because PV is so susceptible to shading, the original layout needed to be reworked several times to accommodate ductwork and other existing impediments.

The 40,000-square-foot, two-ply torch applied modified bitumen roof system by Soprema featured their LEED? compliant, highly reflective Soprastar cap sheet. The membrane surface performs with an initial Solar Reflective Index of 96. This membrane was installed over Concrecel?s lightweight insulated concrete (LWIC). LWIC was chosen for its long lifecycle and ability to be reused when the existing 20-year roof system needs to be replaced. All metal flashings and trim were fabricated from high-recycled content aluminum and attached to Forest Steward Council (FSC)-certified lumber.

The greenroof is comprised of a Tecta Tray modular system with 5,250 square feet of native vegetation including: Muhlly Grass, Purple Love Grass, Frogs Fruit, Blackeyed Susans, Gaillardia, and Sunshine Mimosa, as well as 1,400-square-feet of pavers. Marty Wanielista of Stormwater Treatment Environments, LLC provided the custom blended growth and pollution control media and plants for the project. Slow drip-irrigation covers the system in four independently controlled zones and is fed by a massive underground cistern system. The green tint biodegradable erosion/wind netting protects the entire system for up to one year at which time it will decompose into the growing media.

On a project combining sustainable technologies, one of the most difficult aspects of the project can be scheduling. Since the installers are working with a live eco-system, Mother Nature plays an enormous role, particularly in harsh climates. Florida?s recent remarkably cold winter held planting off until mid-March. In order to save time, the trays were constructed offsite indoors, and shipped to the job site in February for installation with the irrigation. This allowed for a two-day planting once the weather improved. In order to ensure the best success with their greenroof, the building owner chose a 20-year, TectaGreen overburden warranty and a two-year maintenance agreement, which will help with plant establishment and elimination of invasive species.