'Turning Gray Into Green': Maximizing Rooftops For Sustainable, Long-Term Value

In today’s real estate market, having usable rooftop space — or a lack thereof — can make or break a building.

Once viewed as an optional amenity, rooftops have become instrumental in attracting and retaining tenants, whether in multifamily, hotel or office buildings. Rooftop amenity spaces create an environment where people can come together and socialize, work or relax with outdoor furniture, fire pits, coworking spaces and even restaurants and bars. 

As amenity decks continue to gain popularity among tenants and developers alike, Tournesol Siteworks, a California-based commercial landscape product manufacturer, works with landscape architects and developers to deliver impactful rooftop spaces. 

"Thoughtfully designed rooftops with landscape elements are turning gray into green both from a monetization standpoint and an environmental one," Tournesol Siteworks Head of Marketing Carla Dougher said.

Adding planters with native plants, vines, grasses, vegetable gardens and trees not only beautifies the space but can also help cool and shade the building and support pollinators such as birds, insects and bees, which helps to improve biodiversity in urban areas. Strategically placed planters and trellises also function as tools to create spaces and hide unsightly utilities commonly found on roofs.

While many commercial buildings have usable rooftop spaces, they are often underutilized, Dougher said. Rooftops were traditionally home to large utilities including HVAC systems, generators and other infrastructure, and property owners typically left the space largely unused because of these unsightly structures. 

Nowadays, commercial tenants expect more from their spaces. A March report from JLL revealed that outdoor spaces are in high demand, perhaps even more so than any other building amenity. That’s where Tournesol enters the picture.

"A thoughtfully curated rooftop should seamlessly pair functionality with aesthetics," Dougher said. 

Amenities such as lounge areas, outdoor dining tables, pools and shaded pavilions address the functional needs of a rooftop space, while flowers, plants, native grasses, gardens and ambient lighting humanize the space, she said.  

On average, buildings that have rooftop terraces see a 5% rental premium. Other common amenities in commercial buildings, such as fitness centers and electric vehicle chargers, yield considerably less. Adding the most value to the asset and driving up occupancy is of paramount importance when uncertainty afflicts the CRE market.

"Several factors contribute to the success of a rooftop space," Tournesol Head of Sales John Denman said. "It starts with the architect or designer understanding the balance between amenity space and utility space. Products such as planters and trellises can play a large role in strategically concealing utility areas. Additionally, more municipalities are requiring stormwater or bioretention planters as part of the project." 

Bioretention planters are large planters designed to manage stormwater runoff in urban areas. These planters are filled with a thick layer of soil media to absorb and filter the rainwater, reducing runoff volume and pollutants. Excess water that isn't absorbed from a large storm or heavy downpour pools at the bottom of the planter and is slowly released into the storm drain system via an overflow pipe. 

"Tournesol is a leader when it comes to on-structure bioretention planters. We work closely with the project’s design team to deliver a customized solution that enables the property owner to maximize the usable space," Denman said. "Our bioretention planters are a turnkey solution, and they are often smaller and lighter compared to cast-in-concrete, allowing more space for valuable amenities."

Customers appreciate the ability to solve the challenge of bioretention by having functional decorative planters that can match or complement other planters on the site, Denman said. Using lightweight concrete or aluminum allows for a seamless appearance. 

In San Francisco, Handel Architects turned to Tournesol to help bring its vision to life on the rooftop of the new Line Hotel, a 12-story mixed-use hospitality building in the heart of the city. Working with a combination of Tournesol products, the Handel team blended large bioretention planters into the overall rooftop design.

"The result is stunning," Denman said. "The Line Hotel rooftop now features a range of standard and custom planters, including Tournesol’s Kitsap modular metal planter walls as well as planters from its bioretention and Urban collection planters, to create an inspirational garden in the sky."

When developers add plants, trees or flowers to their rooftops, they are doing more than aesthetically enhancing the space — they’re creating a biodiverse ecosystem that positively impacts the local environment, Dougher said. 

Plants of all shapes and sizes can act as air filters. When plants release oxygen into the atmosphere, they also remove toxins and pollutants, ultimately improving human health with better air quality. Plants also attract pollinators, supporting the health of the environment, she said.

Incorporating plants throughout rooftops can also help improve the roof’s overall energy consumption. As plants grow, they provide shade, protecting the space from extreme temperatures and reducing the urban heat island effect — a widespread issue that has detrimental effects on human health and the environment.

"Tournesol’s Greenscreen trellis planters and walls transform hot gray spaces into cool green scenes," Dougher said. "Beyond their aesthetic appeal, they also have several architectural advantages."

The company's Greenscreen trellises act as a shield to mask utilities, create privacy and even help create outdoor "rooms." Other living landscape facades from Tournesol include a wall-mounted trellis, trellis fencing, trellis columns and an infill/overhead trellis.

"With this increased interest from tenants and consumers for outdoor space, there is no better time to learn about the benefits of transforming an unused rooftop space into a gathering place that can have a positive impact on a building, its occupancy rate and on the lifestyle for people who use it," Dougher said. 

This article was produced in collaboration between Tournesol Siteworks and Studio B. Bisnow news staff was not involved in the production of this content.

Studio B is Bisnow’s in-house content and design studio. To learn more about how Studio B can help your team, reach out to studio@bisnow.com.