When recommending sustainable building materials to Jones Pierce’s clients, Cooper Pierce speaks from experience, both as an architect with almost 40 years of experience and as a homeowner of his test lab. Recently, Cooper and the Jones Pierce Architects commercial team installed a green roof above the carport at Cooper’s intown Atlanta home.
Cooper originally planned to hire a crew to implement his earth-friendly green roof design. “I was talking about it with my team, and they said they wanted to work on it,” Cooper says. Since he couldn’t turn down the opportunity for a unique team exercise, he took them up on their offer and extended an invitation to his daughter to join the group.
On the first workday when a tractor-trailer arrived loaded to the brim with material, Cooper hoped the team’s enthusiasm for the project wouldn’t wane. The freshly watered pallets weighed over 100 pounds each and had to be moved off the truck and into a staging location. Luckily, a forklift operator was available for the off-loading of the pallets. Ready to tackle the design challenge, the Jones Pierce team set off to work, setting the plant pallets, wood decking and other materials in place.
The team’s first task was positioning a geotextile slip sheet under the pallet area on the roof to allow for water drainage. The green plant pallets were in 24” square x 4” deep containers and were designed to fit the Ipe deck pallets. (Ipe, pronounced e-pay, is decking; it’s also known as Brazilian Walnut.)
Cooper was impressed with the clever modular system of the plant and deck pallets. “You can create interesting patterns with them, using all green squares or integrating them with Ipe square hardscape as we did,” he says.
The green plant pallets contain low-maintenance, ground-cover and sedum plants that don’t need heavy watering. The pallet depth can be customized to six and eight inches, accommodating a variety of ornamental grasses and other plants.
As our teammates spread out the plants, it became apparent the plant pallets needed finessing to stay lined up to complement the overall pattern. Cooper says, “We kept tucking in little overhanging, loose pieces so the plants could grow over the sides.” He says it was a bit of a learning curve, but the plantings are now well-established, flourishing and look great.
Sustainable applications for commercial and residential properties
The environmental-friendly nature of this type of green roof provides many benefits to homeowners and commercial property developers and owners. The National Park Service reports that the temperature in cities is often higher than in rural areas, known as the urban heat island effect. Green roofs radiate much less heat compared to traditional, darker roofing materials. In addition to green roofs reducing solar radiation through absorption, they also absorb rainwater through plants to reduce runoff.
The economic benefits are just as convincing. Green roofs extend the life of a roof by protecting its surface from damaging sun and heat. (In 2020, the National Weather Service found it was Atlanta’s sixth warmest year on record.) Increasing temperatures cause traditional roof temperatures to soar, resulting in irreversible damage to our environment.
Cooper predicts the demand for green roofs in commercial settings will grow as building owners explore the benefits of a sustainable, green-roof installation, which include:
- More efficient rainwater management with a reduced volume of runoff and improved water quality
- Better air quality coupled with a reduction in heat that helps reduce greenhouse gas emissions
- Energy savings due to reduced HVAC loads and a potential increase in a property’s value
- Historical building applications because of the sustainable roof’s energy-efficient upside and how it can complement areas surrounding the property