The Unexpected Challenges (and Solutions) of Multilevel Warehouse Design

Experiences in Canada and Asia provide case studies for building these complex properties.

Over the past 15 years, multilevel warehouses — particularly those used for retail purposes — have been a growing trend across Asia, and more recently, in the United States. However, some challenges accompany their design and construction that are not encountered in the traditional approach to large-format retail. With operational criteria at the top of the list, these challenges vary heavily based on several factors, including location, footprint, environment, jurisdictional requirements, and even cultural and community influences.

The increase in demand for and construction of multilevel warehouses has unearthed numerous unique considerations not present in traditional warehouse environments. These challenges — each intricate in their own right — have required creative solutions and careful programming to bring each project to life successfully.

Parking and Vehicle Flow

One of the most critical design challenges for vertical warehouses is the traffic flow of vehicles and the structure’s parking. While the goal is to keep the sales level on a single floor for ease of operations and the consumer’s shopping experience, parking for multilevel warehouses can reside either above or below grade. There are pros and cons to both options: Below-grade parking requires excavation, which can increase costs and complications. It does, however, provide a solution for lot coverage or height restrictions in situations where those apply. Above-grade or rooftop parking is preferred as it saves both construction time and money.

Customized resolutions to optimize vehicle traffic flow and increase ease of parking have also been employed, varying not only warehouse to warehouse but also country to country. For example, in Sinjhuang, Taiwan, indication lights for open parking spaces are used to determine capacity at a glance. In Suzhou, China, car ramps at the entrance steer customers directly up to each individual floor, allowing them to bypass full levels. Larger-than-regulation parking spaces — normally very compact in Asia — are also used, granting customers peace of mind. There is no need to worry about maneuvering around tightly packed vehicles in the garage. As an added benefit, oversized spaces also increase vehicle flow; maneuvering in and out of a space is completed in one move vs. two or three.

Customer Journey and Pedestrian Flow

In addition to parking challenges, the flow of customers on their shopping journeys in multilevel warehouses comes with complexities not experienced in traditional large-format retail. Ensuring the ease of navigating traffic flow is one thing, but accounting for the maneuverability of hundreds of oversized shopping carts adds an extra layer of consideration.

Similar to parking, solutions vary with each vertical warehouse project and every environment. Across Asia, MG2 has used both freight-sized elevators and inclined autowalks. Traffic flow varies depending on the time of day, with more customers entering in the morning and more exiting during the afternoon. To accommodate this shift in shopper density, when there are three autowalks, one of them is programmed to change direction midday. In Vancouver, B.C., a dense urban site and multifaceted building structure comprised of street-level frontage, residential towers above and parking below resulted in the design of an elongated atrium housing a fixed ramp to support unique customer flow.

Culture also plays a role in determining multilevel warehouse customer journey solutions. In South Korea, for example, consumers favor elevators significantly more than autowalks, regardless of wait time. The MG2 team adjusted future designs — specifically for South Korea-based vertical warehouses — to accommodate these cultural preferences.

Regional, Operational and Sustainable Considerations

Regionality is almost always a consideration for the design and construction of multilevel warehouses. Particularly challenging are building footprint and site conditions, lot coverage and height restrictions, community involvement and consultation, and sustainable design, build and operational requirements.

For example, in Linda Vista, Mexico, lush landscaping combines with open-air autowalks, parking decks, cafe seating and a porte-cochère-style entry to take advantage of the area’s year-round warm weather. With an elevated warehouse sales level, its design also needed to be adjusted to accommodate access from the street. After many outreach sessions with the community, the agreed-upon solution was to move people through a series of outdoor ramps and freight elevators located at the street corner entry. 

In the Santa Fe neighborhood of Mexico City, MG2 faced the unique challenge of designing a multilevel warehouse that not only catered to the surrounding metropolis but also was seamlessly integrated — both visually and functionally — into La Parque Mexicana, a bordering urban green space. In addition to the green facades that “hide” the structure, a green roof with custom HVAC housing, a soccer field and a connection to the existing park have been incorporated into the design and operations.

In Manhattan, well-known for its density, a small footprint requiring below-grade construction presented different challenges. Needing to pump the structure’s sewage up and out, MG2 worked closely with the city to employ unique solutions that addressed the operational requirements not encountered elsewhere in the country. The developer also sought the opportunity to add residential towers in the future, so concrete structures were incorporated into the design of the warehouse to accommodate both this residential addition and the operational footprint.

Technology Solutions for Multilevel Warehouse Design

To quickly address the unique challenges presented from the varying factors described above and still maintain efficiency in design, construction and speed to market, MG2 employs a number of technologies, strategies and tactics.

Using Revit as a standard for BIM models ensures that construction documentation is complete and precise as it changes hands. In addition, these models allow for the creation of virtual-reality walkthroughs for both staff and stakeholders, giving them the opportunity to see the solutions and designs utilized much more quickly than in-person meetings would.

MG2 has also gained insight into materials optimization and construction techniques by working on multistory warehouses in numerous countries and continents, including more than 60 in Asia alone. Popular solutions in some countries may save time and money when used in others. Moving ramps are one example. While fixed ramps are preferred today in the U.S., in Asia the public is familiar with this solution, and it’s one that has the potential to be incorporated stateside in the future.

The Future is Bright

Overall, the trend for multilevel warehouses should continue to rise. Urban centers today want and need warehouse services that have, until recently, only been offered in suburban locations. There are unique factors that make multilevel warehouses successful. Understanding the challenges that impact the speed, repetition and efficiency required to bring these vertical retail warehouses to life is the key.

Russ Hazzard, AIA, is president of MG2 in Seattle; Jonathan Chang, AIA, is a principal at MG2 in Shanghai.