Effective and Efficient Structure Design

The planning and design of parking structures has evolved well beyond the days of a simple concrete structure with attendants staffing cashier booths.

Specifically, the planning and design of parking structures in urban spaces involves an integrated design approach that involves the building team and owner throughout the lifetime of the project. The planning and design of parking structures in urban areas can present detailed challenges related to engineering the proper solution as it relates to the site location, traffic planning for vehicular ingress and egress, proper aesthetics, economic impact of the parking structure, and sustainability.

Walter P Moore’s Parking Services Group have been involved in the design and engineering of parking structures around the country that have required collaboration of the entire design team, as well as the owner, to provide an effective and efficient design that addresses the proper criteria to ensure the successful movement and storage of vehicles.

The three projects examined below were recently constructed in urban areas. Each project is diverse as it relates to the planning and design required by the design team and owner. By comparing and contrasting each of the projects, the functional planning and design standards are examined to provide viable takeaways that can be used for the next iteration of parking garage design.

Bank of America Tower

When it comes to assessing the parking demand for a development, the first component to look at is location. For example, a suburban office space typically requires a parking-demand ratio between 2.5 and 3.0 parking spaces for every 1,000 gross square feet (gsf). For a 500,000-gsf building, the parking demand can range from 1,250 to 1,500 parking spaces.

On the flip side, the same size development in an urban location requires a much smaller parking demand ratio—closer to 1.5 to 1.75 parking spaces per 1,000 gsf of office space. This equates to an approximate demand of 750-875 parking spaces.

For the Bank of America Tower in Houston, Texas, a 2021 IPMI Award of Excellence honoree for best design of a mixed-use parking and transportation facility, the developer wanted a garage designed with a parking ratio of between 1.5 and 2.0 parking spaces per 1,000 square feet. While the number of parking spaces provided an oversell ratio of 1.15, the developer was able to design a structure with a parking ratio close to 2.0.

This strategy was crucial in attracting the desired tenant for the building, which features mixed-use components including offices, retail, and outdoor space within the building’s footprint. Bank of America Tower is also located in the central business district, near entertainment, public park space, and various transit options.

Because there was flexibility with the construction schedule, the first phase of the Bank of America Tower project constructed was the parking garage. This allowed the developer the opportunity to generate parking revenue for a full year while the design and construction of the 35-story tower was completed.

The 11-story, 1,360-space parking structure was designed with a state-of-the-art outdoor sky park that sits atop the structure as the 12th floor. The sky park—the only tenant amenity of its type in Houston—provides tenants of the Bank of America Tower a unique outdoor space with views of downtown while nestled between trees and wooden canopies, but it also serves as a model for sustainable urban structures.

The Bank of America Tower is the first project in the United States to achieve LEED v4 Platinum Core and Shell Certification. It was the only LEED v4 project to attempt the Whole Building Life Cycle Assessment (WBLCA) credit, which Walter P Moore led. The WBLCA allowed the building team to identify combinations of materials that made the most significant contributions to environmental impacts and develop reduction strategies accordingly. Based on these studies, the team developed a strategy of aggressive cement minimization, which led to a projected 19 percent reduction in global warming potential and a 12 percent reduction in acidification.

Patrons of the garage utilize a state-of-the-art Parking Access and Revenue Control System (PARCS) that efficiently manages both contract/monthly and transient/visitor parking needs. An Automatic Vehicle Identification (AVI) Reader system was specifically specified to facilitate the rapid ingress and egress of contract parkers and provides hands-free access. Visitors utilize a convenient Pay-on-Foot (POF) and Pay-in-Lane system.

To accommodate the 1,365 parking spaces and provide a high level of service, the Bank of America Tower garage was designed with an innovative express ramp system (no parking on ramp) at the ground floor that provides access to two major streets, and allows up to 40 percent more area for retail and back of house opportunities over a traditional ramping system.

At level 2 of the garage, the express ramp system transitions to a traditional double helix ramping system. The one-way double helix ramping system was chosen to accommodate the large peak loading conditions from the office patrons while providing an intuitive traffic flow. Crossovers are provided at each level which enhances the level of service over a traditional double helix system.

Bay widths are two feet wider than what is normally accepted for angled parking to provide a higher Level of Service (LOS) for all patrons. End bays are also larger to provide comfortable turning maneuvers and easily accommodate full size trucks and SUV’s.

Both the tower and parking garage are wrapped in a beautiful glass curtain wall system with varying levels of contrast and metal accents to provide a sophisticated appearance. As the garage takes up a significant portion of the site, the architects wanted to ensure that the tower and garage appeared as a seamless project. From the street level, one cannot tell where the building footprint ends, and the garage footprint begins.