1315 Peachtree Street

Challenge

The design of the project site prior to redevelopment privileged the circulation and parking of automobiles. The space between the building and sidewalk was dominated by a circular drive that was used for loading/unloading and to access ground-level parking within the building podium. A primary goal for the redevelopment was to create a durable, inviting, and multifunctional space that engages Peachtree Street while accommodating small and large group events. The required flexible design and durable materials also had to satisfy the project’s stormwater management objectives and create a comfortable microclimate on the westward facing aspect.

Solution

The driveway was removed and replaced by a 2,280-sf public plaza that provides access to the building’s newly finished street level. The plaza connects the building to the public way and provides an inviting, new public space that also serves as a social space for building occupants and an event space for the buildings tenants (Museum of Design Atlanta and Atlanta-Fulton Public Library). To manage stormwater, rainwater is harvested from the building’s roof, and the plaza incorporates permeable pavers, rain gardens and a suspended deck surrounding new trees, which allows runoff from the plaza to infiltrate into the uncompacted planting soil below. These new shade trees and the high SRI rating of the concrete pavers help to create a more comfortable microclimate in this west-facing plaza.

• Roof runoff is harvested and treated to provide water for irrigation, the site water feature, and wastewater conveyance. The harvested water is treated by a bag filter and UV filtration system and stored in a 10,000-gallon underground cistern.
• Water for site irrigation is sourced from the harvested rainwater. The system is controlled by Rain Bird ESP-SMT Smart Modular Control System and distributed via drip irrigation. When the water in the cistern drops below a predetermined level, the irrigation supply is disabled. Irrigation with potable water is only done (by hand) during periods of drought.
• An outdoor “runoff-driven” water feature is entirely supplied by harvested rainwater. A sensor in the reservoir shuts off the fountain when non-potable water in the tank reaches a predetermined level and potable water is introduced into the system. The presence of water emerging from the fountain serves as a visual reminder of the availability and preciousness of our water resources. Harvested rainwater also fills a lobby-level water feature.
• A rain garden on the side of the ground level plaza receives stormwater runoff from the plaza, allowing for infiltration and stormwater cleansing. The rain garden is planted with three species that have edible and medicinal value and are suited for such hydrologic conditions.
• The 2,280-sf street level public plaza offers a civic space for the Museum of Design Atlanta and Atlanta-Fulton Public Library to hold community and private events. The plaza is surfaced with FSC-certified Massaranduba decking and concrete pavers, which are spaced with pervious material to allow infiltration of stormwater into the sand, leveling course, and aggregate sub-base. The pavers have an SRI value of 60.
• The maintenance parking lot is surfaced with pervious concrete installed over a gravel sub-base, which allows for stormwater infiltration.
• 11 new site trees create more comfortable microclimates and mitigate the site’s contribution to the urban heat island. The tree species are 3 Acer buergeruanum ‘ABMTF’ (Trident Maples), 1 Magnolia virginia (Sweetbay Magnolia), 3 Ilex vomitoria (Yaupon Holly), and 4 Acer rubrum ‘Karpick’ (Armstrong Red Maples).
• All of the trees have at least 250 cf of soil and half of them have at least 750 cu ft of soil. A suspended decking system over 3 ft of engineered soil was used to provide space for tree root growth while maximizing the plaza surface. (Due to their higher void ratio, engineered soils hold greater volumes of stormwater and allow for greater oxygen delivery to plant roots.) The decking and a soil management plan protect the soil from compaction and degradation.
• Edible plants were used on the fifth level terrace and the ground level planting beds. Medicinal plants were also used as a reference to the firm’s extensive healthcare practice, including Vaccinium darrowii ‘Rosa’s Blush’ (Darrows’ Blueberry) & Vaccinium ashei (Rabbiteye Blueberry), Rosemarinus officianalis ‘Tuscan Blue’ (rosemary), Lavendula angustifolia (lavender), Hamamelis x intermedia ‘Arnold’s Promise’ (Arnold’s Promise Witchhazel), and others. These plants are available for use by employees and visitors.
• The fifth floor terrace provides expansive views across the city and into the adjacent High Museum of Art grounds and 1315 plaza below. The 24 chairs and four tables on the terrace offer employees and guests a place of respite for meetings and socializing. Made of extruded aluminum with a polyester powder coat finish, the site furnishings are highly recyclable and resistant to corrosion, leading to longer lifespan and reduced expense due to maintenance and replacement.
• The pedestal system that supports the decking tiles on the fifth floor terrace contains 20% post-industrial recycled material and is 100% recyclable. Additionally, the pedestals are made in the USA.
• The specification and strategic location of high-efficiency light fixtures minimizes the amount of light trespass beyond the site boundary. Cut-off classification of specified fixtures reduces the amount of light emitted and minimizes light pollution.

By specifying Massaranduba wood decking tiles constructed from ‘shorts’ for the plaza and terrace, the project saved $64,155. Shorts are the leftover pieces from the fabrication of other wood products. Using shorts reduced the materials cost by 78% compared to using comparable decking tiles manufactured from long boards.

• Having an accurate understanding of local review agency perceptions helps reduce the need for design changes later in the design and construction process. The Atlanta Midtown Alliance saw the original design intent for a bioswale planted with native grasses and perennials as a planting of weeds. Helping regulatory boards and the community understand and appreciate the value of revealing stormwater management and native vegetation could have mitigated design changes and ensured the execution of the original design.
• The provision of interpretive signage or similar means of communication would help site visitors and building guests more clearly understand the connection between design elements and corporate values. For example, Perkins+Will has a significant presence in the health care facilities sector, and the medicinal plants on-site reference this health care practice. Perkins+Will believes that additional signage, pamphlets for self-guided tours, or scannable QR codes throughout the site would help communicate the purpose and meaning behind the design.
• High wind causes water falling from the water feature to blow away from the capture basin, causing a fair amount of water to be lost from the cistern system. It would be beneficial to install a wind meter which shuts the fountain off during periods of high wind. Future development on the site immediately south of the water feature may provide a wind block and mitigate water losses. Additional water is lost as water is deflected off river stones suspended by a grate that disguise the feature’s basin. This loss could be prevented by including a shield in the grate that holds stones away from the falling water.
• Wastewater conveyance is the top priority when it comes to greywater budgeting, making harvested rainwater unavailable for irrigation during periods of drought. Since the irrigation system is only sourced from the cistern and not the city’s potable water line, hand watering is sometimes, but rarely used as the plantings are now well established. It would have been beneficial to install a larger cistern or a separate cistern dedicated as irrigation supply.

Decking: Bison Innovative Products 
Irrigation: Rain Bird
Lighting: BEGA US; Cooper Lighting
Pavers: Stepstone
Furniture: Knoll
Crushed Slate: Rockmart Slate Corporation
Engineered Soil: ItSaul Natural- Complete Landscape Mix

Project Team

Client: Perkins+Will 
Landscape Architect: Perkins+Will 
Architect: Perkins+Will 
Structural Engineer: Uzun & Case Engineers, LLC 
Civil Engineer: Kimley–Horn and Associates 
Mechanical and Plumbing Engineer: Integral Group 
Fountain/Cistern Designer: Perkins+Will/McKenney’s, Inc. 
Cost Estimator: Brasfield & Gorrie 
LEED Commissioner: BVM Engineers (since been acquired) 
Contractors: Brasfield & Gorrie

Role of the Landscape Architect

The landscape architect was an integral part of the design team from the beginning and shaped important design decisions, such as the elimination of a circular driveway in order to re-purpose the space for a new pedestrian-oriented plaza. The landscape architect worked with the architect and ownership team on establishing the street-level circulation and building entrance locations, and then designed the full landscape and hardscape for the entry plaza and fifth-level terrace.