Tag Archives: TPP-2013-10-

Common Ground

TPP-2013-10-Common GroundBy Helen Sullivan, APR, Fellow PRSA

Parking professionals in the United States are keenly aware of the challenges and opportunities facing the industry in their own country, but what about their counterparts around the world? Do professionals in other countries have similar priorities, successes, and frustrations? Do they prioritize sustainability and agree that the public’s perceptions of parking are steadily improving?

As IPI Executive Director Shawn Conrad, CAE, discovered on his travels to parking conferences around the world, the leaders of parking associations have much to gain when there is time for dialogue and discussion.

“The sweeping changes in the industry are affecting everyone, yet we have long been relatively insulated from one another,” he says. “During the past few years, we felt the time was ripe to more effectively tap the expertise and experiences of our counterpart parking association leaders by forming a forum to address our common goals.”

That forum is the Global Parking Association Leaderships (GPALs) Summit. Established by IPI, the organization met first at the 2012 IPI Conference & Expo in Phoenix, and again last month at the European Parking (EPA) Congress, hosted by the Irish Parking Association in Dublin.

GPALs’ first collaborative project: to take the pulse of the global parking industry through a survey based on an adaptation of IPI’s annual Emerging Trends in Parking survey. A subcommittee, including Keith Gavin, (Ireland), Patrick Troy, (UK), Carole Whitehorne (Canada), Larry Schneider (Australia), Andre Piccoli (Brazil), Nick Lester (EPA), and Conrad (U.S.), worked closely to prepare a survey for distribution to participating countries.

“We were impressed by the universal willingness to participate in the survey and the excitement it generated, especially in countries such as Japan with whom we previously had little contact,” says Conrad. “Not surprisingly, we share many of the same issues, but the survey revealed some clear differences in countries’ priorities and circumstances.”

Each country received a report of its own constituents’ responses, and all the surveys were analyzed by the Washington, D.C.-based Market Research Bureau, with assistance from Giuliano Mingardo, senior researcher in the Department of Regional, Port and Transport Economics at Erasmus University in Rotterdam, the Netherlands.

Results were first shared at last month’s GPALs gathering and then at the EPA Congress by past IPI Chairs Cindy Campbell and Casey Jones, CAPP.

“The GPALs Global Parking Survey is a valuable snapshot and the beginning of knowledge building and collaborative projects among parking associations around the world,” says Jones.

Technology Rules the Parking Industry
The U.S. certainly is not alone in feeling the reverberating effects of technology in the parking industry. Throughout the world, technologies such as GPS and mobile phones, electronic payment, and sensor space monitoring systems are making it easier for parking professionals to meet the demands of drivers. Among 21 countries polled, the majority listed the move toward innovative technology as the leading industry trend.

Sustainability is a Focus
Sustainability is a broadly-shared global concern, with most respondents saying the greatest environment benefit for parking comes from on- and off-street guidance systems that enable drivers to find spaces faster, reducing carbon emissions. Coming in a close second is energy-efficient lighting, which is seen as one of the top three priorities for a majority of countries, particularly Germany (85 percent) and Brazil (72 percent). The third leading trend—encouraging alternative travel through bike storage, car and bike share, and access to mass transit—is clearly seen as a priority in Norway (70 percent), followed by Britain, Australia, Ireland, Brazil, and the U.S.

Another subject raised by both the survey and the EPA Congress was the parking industry’s role in accommodating electric vehicles (EVs). IPI is working with the U.S. Department of Energy to develop standardized guidelines to be released later this year, and it appears that other countries are assuming an equally proactive role. Antoni Roig, GPALs’ representative from the Parking Association of Spain (ASESGA), noted that his country will soon be required to allocate as much as 20 percent of its parking spaces to EVs.

Others at the meeting, including Nick Lester of the EPA, pointed out the need for better communication with the automobile industry to ensure that the industry’s capabilities are keeping pace with their developing technologies. Perhaps one of the meeting’s most intriguing questions was raised by Tamas Szirmay of the Hungarian Parking Association: How do we deal with the legal and liability issues that will arise as new automated driving/parking technology becomes more mainstream?

Which Cities Are More Progressive?
When it comes to parking innovations, are any cities seen as leading the pack? Asked to name up to three cities within or outside of their own countries they would consider trendsetting or progressive, respondents most often cited London (named by nine countries), San Francisco (seven countries), Amsterdam and Paris (five countries each), and Barcelona, Seattle, and Tokyo (four countries). In the U.S., respondents also identified New York, Los Angeles, and Washington, D.C. While no city is free from parking and transportation issues, the responses suggest that professionals around the world can learn much each other.

Public Perception

Through its Parking Matters® program and other education and awareness efforts, IPI has worked hard to improve public perceptions, and annual polls of its members confirm that the association is making headway. GPALs survey results suggest that may not be the case everywhere. In Spain, for example, two-thirds of respondents felt attitudes about parking remain negative and unchanged, as do half of those surveyed in Britain and Australia, and 40 percent of those in Norway. Germany’s respondents are split between feeling attitudes are improving (36 percent) and actually becoming more negative (40 percent).

As Conrad pointed out at the EPA Congress in Dublin, improving public perceptions “is not a sprint, but a marathon,” and the continuous challenge is to keep messages on target and seize educational opportunities.

Most respondents agree that more collaboration is needed, particularly between parking professionals, urban planners, and local government officials. This was most strongly voiced by representatives of the Scandinavian countries, but at least half of those polled in Australia, Britain, and Canada concurred. In the U.S., urban planners, architects, and local government officials emerged as the three groups most in need of parking education.

These results echoed what IPI has long advocated: the need to tap parking expertise earlier in the urban planning process to avoid later issues with economic development, transportation flow, congestion, and design.

Societal Factors
A majority—11 of 13 countries surveyed—listed traffic congestion as one of the most significant societal influences on parking. (Australia, Canada, and the U.S. viewed traffic congestion as the leading influence, followed by Brazil, Britain, and Germany). One-third of respondents believe that parking’s greatest future challenge will be dealing with a scarcity of space and resources and rising mobility costs in urban areas.

Interestingly, other societal influences on parking varied by region. They included economic pressures on retailers (listed first by Brazil, Britain, Ireland, and Spain), increased fuel prices (listed first by Spain and second or third by six other countries), a focus on environment and sustainability, and desires for more liveable, walkable communities (both of which were rated most highly by all three Scandinavian countries, followed by Canada, Germany, and the U.S.). Security was a top issue in Germany.

Although only Brazil noted that parking issues stem from a shortage of qualified employees, several countries agreed on the need for industry education and professional development.

Scheduled to convene again at the 2014 IPI Conference & Expo in Dallas in June, GPALs has appointed an advisory council that will decide on future projects, including a directory of participating parking associations.

As Conrad says, “The important thing is that we are finally bringing our industry together to collaboratively address issues and seize the future’s limitless opportunities.”

For more information and downloadable survey charts, visit parking.org/gpals.

Helen Sullivan, APR, Fellow PRSA, is IPI’s communications counsel. She can be reached at sullivan@parking.org.

TPP-2013-10-Common Ground

From the Ground Down

TPP-2013-10-From the Ground DownBy Rich Wagner, CAPP

Permeable paving includes a range of sustainable materials and techniques for using pavements with a base and sub-base that allow stormwater to move through the surface. In addition to reducing runoff, this structure effectively traps suspended solids and filters pollutants from the water.

Although some porous paving materials appear nearly indistinguishable from nonporous materials, their environmental effects are qualitatively different. Whether pervious concrete, porous asphalt, paving stones, concrete, or plastic-based pavers, all pervious materials allow stormwater to percolate and infiltrate the surface areas. The goal is to control stormwater at the source, reduce runoff, and improve water quality by filtering pollutants in the substrata layers.

Permeable solutions can be based on porous asphalt and concrete surfaces, concrete pavers (permeable interlocking concrete paving systems, or PICP), or polymer-based grass pavers, grids, and geocells. Porous pavements and the voids between concrete pavers allow water to drain through a stone base layer. Polymer-based grass grid or cellular paver systems offer load-bearing reinforcement for unpaved surfaces of gravel or turf.

Grass pavers, plastic turf reinforcing grids (PTRG), and geocells (cellular confinement systems) are honeycombed 3D grid-cellular systems made of thin-walled high-density polyethylene (HDPE) plastic or other polymer alloys. These provide grass reinforcement, ground stabilization, and gravel retention. The 3D structure reinforces infill and transfers vertical loads from the surface, distributing them over a wider area. Selection of the type of cellular grid depends to an extent on the surface material, traffic, and loads. The grids are installed on a prepared base layer of open-graded stone (higher void spacing) or engineered stone (stronger). The surface layer may be compacted gravel or topsoil seeded with grass and fertilizer. In addition to load support, the cellular grid reduces compaction of the soil to maintain permeability, while the root channels improve it.

Porous pavements protect watersheds in new suburban development. In existing neighborhoods and towns, redevelopment and reconstruction are opportunities to implement stormwater water management practices. Permeable paving is an important component in low-impact development (LID), which is a process for land development that attempts to minimize effects on water quality.

The infiltration capacity of native soil is a key design consideration for determining the depth of base rock for stormwater storage or for whether an underdrain system is needed.

Advantages of Permeable Pavement

  • Managing runoff. Large volumes of urban runoff cause serious erosion and siltation in surface water bodies.
  • Controlling pollutants. Permeable paving surfaces keep pollutants in place in the soil or other material underlying the roadway, and allow water seepage to groundwater recharge while preventing stream erosion problems. They capture heavy metals and prevent them from washing downstream. In void spaces, naturally-occurring microorganisms digest car oils, leaving little behind but carbon dioxide and water. Rainwater infiltration is usually less than that of an impervious pavement with a separate stormwater management facility somewhere downstream.
  • Trees. Permeable pavements may give urban trees the rooting space they need to grow to full size. A structural soil pavement base combines structural aggregate with soil, offering a porous surface that admits vital air and water to the rooting zone. This integrates healthy ecology and thriving cities with the tree canopy above, the city’s traffic on the ground, and living roots below. The benefits of permeable pavement on urban tree growth have not been conclusively demonstrated and many researchers have observed tree growth is not increased if construction practices compact materials before permeable pavements are installed.

Challenges of Permeable Pavement

  • Runoff volumes. Permeable pavements are designed to replace effective impervious areas (EIAs), not manage stormwater from other impervious surfaces on-site. Use of this technique must be part of an overall on- site management system for stormwater and is not a replacement for other techniques. In a large storm event, the water table beneath porous pavement can rise, blocking the precipitation from being absorbed into the ground. The best way to prevent this problem is to allow for adequate rainwater runoff at the pavement design stage.

    Pollutant load.
    Highly-contaminated runoff can be generated by some land uses in which pollutant concentrations exceed those typically found in stormwater. These “hot spots” include commercial nurseries, recycling facilities, fueling stations, industrial storage facilities, marinas, some outdoor loading facilities, public works yards, hazardous materials generators (if containers are exposed to rainfall), vehicle service and maintenance areas, and vehicle and equipment washing and steam cleaning facilities. Due to the potential for groundwater contamination, porous pavement should not be applied at stormwater hot spots. All contaminated runoff should be prevented from entering municipal storm drain systems by using best management practices for the specific industry or activity.
  • Weight and traffic volumes. Reference sources differ on whether low or medium traffic volumes and weights are appropriate for porous pavements. For example, near truck loading docks and areas of high commercial traffic, porous pavement is sometimes cited as being inappropriate. However, given the variability of products available, the growing number of existing installations in North America, and targeted research by both manufacturers and user agencies, the range of accepted applications seems to be expanding. Some concrete paver companies have developed products specifically for industrial applications. Working examples exist at fire halls and busy retail complex parking lots, and on public and private roads, including intersections in parts of North America with severe winter conditions.

Challenges and Considerations
Siting is an important consideration when considering permeable pavement installation. Permeable pavements may not be appropriate when land surrounding or draining into the pavement exceeds a 20 percent slope, where pavement is down-slope from buildings, or where foundations have piped drainage at their footers. The key is to ensure that drainage from other parts of a site is intercepted and dealt with separately rather than being directed onto permeable surfaces.

Cold climates, too, may present special challenges. Road salt contains chlorides that could migrate through the porous pavement into groundwater. Snow plow blades could catch block edges and damage surfaces. Sand cannot be used for snow and ice control on pervious asphalt or concrete because it will plug the pores and reduce permeability. Infiltrating runoff may freeze below the pavement, and cause frost heave, though design modifications can reduce this risk.

These potential problems do not mean that porous pavement cannot be used in cold climates; in fact, porous pavement designed to reduce frost heave has been used successfully in Norway. Furthermore, experience suggests that rapid drainage below porous surfaces increases the rate of snow melt above.


It’s true that some estimates put the cost of permeable paving at two to three times that of conventional asphalt paving. Using permeable paving, however, can reduce the cost of providing larger or more stormwater best management practices onsite, and these savings should be factored into any cost analysis. Interesting to note is that the off-site environmental impact costs of failing to reduce on-site stormwater volumes and pollution have historically been ignored or assigned to other groups (local government parks, public works and environmental restoration budgets, fisheries losses, etc.). Many cities across the country are studying the use of pervious concrete quite closely and finding that new stormwater regulations are making it a viable alternative to stormwater ponds.

Longevity and Maintenance
Some permeable pavements require frequent maintenance because grit or gravel can block their open pores. This is commonly done by industrial vacuums that suck up all the sediment. If maintenance is not carried out on a regular basis, the porous pavements can begin to function as impervious surfaces. Thanks to more advanced paving systems, required maintenance can be greatly decreased. Elastomerically-bound glass pavement requires less maintenance than regular concrete paving

Plastic grid systems are gaining popularity among local government maintenance personnel, owing to the fact that they reduce the need for gravel migration and weed suppression in public park settings.

Some permeable paving products are prone to damage from misuse, such as drivers who tear up patches of plastic and gravel grid systems on remote parking lots at night. The damage is not difficult to repair, but can look unsightly. Grass pavers require supplemental watering in the first year or they may need to be re-seeded. Regional climate also means that most grass applications go dormant during the dry season. While brown vegetation is only a matter of aesthetics, it can influence public support.

Traditional permeable concrete paving bricks tend to lose their color in relatively short time; this can be costly to replace or clean and is mainly due to the problem of efflorescence.

Efflorescence is a hardened crystalline deposit of salts that migrate from the center of concrete or masonry pavers to the surface to form insoluble calcium carbonates that harden on the surface. Over time, these deposits form on parking lots in a way much like stalactites in caves. Efflorescence usually appears white, gray, or black depending on the region.

After awhile, efflorescence begins to negatively affect the overall appearance of masonry or concrete, and may cause the surfaces to become slippery when exposed to moisture. Left unchecked, this efflorescence will harden and their calcium/lime deposits will begin to erode the cement paste and aggregate. In some cases, it will also discolor stained or coated surfaces.

Efflorescence forms more quickly in areas that are exposed to excessive amounts of moisture such as near pool decks, spas, and fountains, or where irrigation runoff is present. As a result, these affected regions become very slick when wet. This can be of serious concern as a public safety issue to individuals, principals, and property owners, exposing them to possible injury and increased general liability claims.

Efflorescence remover chemicals can be used to remove calcium/lime buildup without damaging the integrity of the paving surface.

Pavement Considerations
Nine different families of porous paving materials each present distinctive advantages and disadvantages for specific applications:
Pervious concrete is widely available, can bear frequent traffic, and is universally accessible. Pervious concrete quality depends on the installer’s knowledge and experience.

Plastic grids allow for a 100 percent porous system that uses structural grid systems to contain and stabilize either gravel or turf. These grids come in a variety of shapes and sizes for use on everything from pathways to commercial parking lots. These systems have been used in Europe for more than a decade, and are gaining popularity in North America due to environmental building requirements. The ideal design for this type of grid system is a closed cell system, which prevents gravel, sand, and turf from migrating laterally.

Porous asphalt is mixed at conventional asphalt plants, but fine (small) aggregate is omitted from the mixture. The remaining large, single-sized aggregate particles leave open voids that give the material its porosity and permeability. Under the porous asphalt surface is a base course of further single-sized aggregate that acts as a reservoir where water can be allowed to evaporate and/or percolate slowly into the surrounding soils. Porous asphalt surfaces, called open-graded friction courses (OGFC), are used on highways to improve driving safety by removing water from the surface. OGFCs are not full-depth porous pavements, but offer a porous surface course, usually .75 to 1.5 inches thick, that allows for the lateral flow of water through the pavement, improving the friction characteristics of the road and reducing road spray.

Single-sized aggregate without any binder (e.g. loose gravel or stone chipping) is another alternative. Although it can only be safely used in very low-speed, low-traffic settings such as parking lots, its potential cumulative area is great.

Porous turf, when properly constructed, can be used for occasional parking such as that at churches and stadiums. Plastic turf reinforcing grids can be used to support increased load, and turf transpires water, actively counteracting the heat island effect with what appears to be a green open lawn.

Permeable interlocking concrete pavements are concrete or stone units with open, permeable spaces between the units. They offer an architectural appearance and can bear both light and heavy traffic, excepting high-volume or high-speed roads. Some products are polymer-coated and have an entirely porous face.

Permeable clay brick pavements are fired clay brick units that feature open, permeable spaces between the units. Clay pavers provide a durable surface that allows stormwater runoff to permeate through the joints.

Resin-bound paving is a mixture of resin binder and aggregate. Clear resin is used to fully coat each aggregate particle before laying. Enough resin is used to allow each aggregate particle to adhere to the next and to the base, leaving voids for water. Resin-bound paving provides a strong and durable surface that is suitable for pedestrian and vehicular traffic in applications such as pathways, driveways, car parks, and access roads.

Elastomerically bound recycled glass porous pavement consists of bonding processed post-consumer glass with a mixture of resins, pigments, and binding agents.

Rich Wagner, CAPP, is general manager with Republic Parking System. He can be reached at rwagner@republicparking.com or 860.524.0505.

TPP-2013-10-From the Ground Down

Open Possibilities

TPP-2013-10-Open PossibilitiesBy John Barnett

Architect John Capdevielle, II, Baton Rouge, La., says the tendency for those in his profession to get set in their ways is natural. Despite being in his mid-60s, he is resisting that tendency because new technology and new construction materials can bring improved performance and reduced costs to his clients. That is why he is interested in castellated beams.

Capdevielle notes that the castellated beam has been part of a structural steel approach that has been around for years, but is still not well known among architects. The profession needs to know about it, he says, because the castellated beam can be a better alternative to traditionally used concrete beams, wide-flange steel beams, and steel joists. And when designers and builders come to understand the cost and performance advantages of the castellated beam, he says, they can base a project on leveraging those unique advantages.

Beam Advantages

A major advantage is a smaller floor-to-floor profile than other beams because ductwork can be worked underneath or into the holes of the shallow beams, which are easy to line up. Another advantage is a lighter structure that results from the use of fewer members to create more open spaces, which also reduces foundation costs. The beams have the same structural integrity as wide-flange solid web beams, but can offer a more efficient use of steel. They help reduce floor bounce and are often made of recycled materials, Capdevielle says.

“The castellated beam has changed my outlook on parking garage design, because the beam is ideal for longer spans and shallower depths, it eliminates extra interior posts and columns, and it will keep the size of the garage elevation down compared to the adjacent building,” Capdevielle says. He recommends thinking about all that the castellated beam approach can do, and then making the design adhere to those capabilities.

“To help lead the way, as an architect, all I need to do is to retool my thinking process,” Capdevielle says.

Design Considerations
Betty M. Corkwell, PE, design engineer for castellated beam manufacturer New Millennium Building Systems, Continental, Ohio, notes that it’s possible to produce a single 90-foot FreeSpan™ beam section and that even greater lengths can be achieved when necessary by using multiple spliced sections. Any required infill sections can be manually welded for special connection points.

To produce the beam, manufacturers start with an AISC standard designation beam that has a continuous web, cut a zigzag pattern along the web, shift it, and put it back together (see Figure 1). “When we do that, we increase the depth,” she says. “The rule of thumb is one and a half times the root beam depth, depending on the cutting pattern we use.”

Because of the unique concept behind the beam, Corkwell must use different design characteristics than she would for traditional pieces. The castellated beam behaves differently under loading stresses than a conventional beam would. According to Corkwell, the stresses are more “global” with a castellated beam. “It’s just something you don’t have to design for when you’re designing a standard wide-flange section beam,” she says, adding that she often assists engineers who are contemplating the use of castellated beams in facilities.

Her company typically produces castellated beams in 60-foot spans, and their strength is dictated by the facility where they will be in service. “In typical garage loading requirements, a beam about 30 inches deep, designed at 60 pounds per foot with composite construction, will have strength and serviceability requirements,” Corkwell says. Compared with wide-flange beams, castellated beams save about one-third of the weight per foot, which translates to reduced overall mass of the structure, reduced lateral forces, and reduced foundation loads. Castellated beams also impart an open, airy look to a parking garage, thanks to the openings in the beams, Corkwell adds.

Building Advantages
Castellated beams become basic structural elements within the design of an entire building, just like a wide-flange beam. They are erected the same way and the connections are the same, Corkwell says, adding that the holes that result from the cutting might need infilling if perpendicular connections are present. “The erector doesn’t see a difference,” she says. “But at the back end, the owner can see the possibility of running all of their mechanical, electrical, plumbing, and ductwork through the holes.”

Beams are offered in straight, camber, and combined weight options, as well as galvanized options, and are manufactured from 96 percent recycled materials.

It’s important to ensure that manufacturers have quality controls in place to ensure structural integrity is paramount, Corkwell says. “When we discussed getting into this fabrication process, one of the first things we did was to become an AISC-certified fabricator. AISC is very diligent about monitoring fabrication processes. We make sure that we keep all of the paperwork that’s required on a particular project and maintain our equipment in a certain way. We make sure that everything is up to AISC standards when it comes to our production.”

In Service

It is estimated that incorporating castellated beams into a parking garage can reduce the cost of construction by up to 10 percent compared with concrete construction. Cost is obviously important, but design flexibility for a parking facility is another major benefit of castellated beams.

The fact that mechanical, electrical, and plumbing (MEPS) can be fed through the holes of castellated beams results in greater head height. Head height is sacrificed in concrete construction because sprinkler piping must be run under the bottom ledge of the concrete for drainage. Additionally, the concrete must be raised to allow cars to pass under. Because MEPS can be fed through the holes in castellated steel beams, floor-to-floor heights can be designed closer together while offering the same head height found with alternative methods. Additionally, the need for dropped interior beams is eliminated.

Improved lighting is another major benefit of using castellated beams. MEPs aren’t the only thing passing through the holes in the beams—natural light also passes through. The amount of necessary artificial light is reduced and dark spots can be eliminated.

Parking facilities that use castellated beams are very cost-efficient. Particularly when the galvanized option is chosen, they require little maintenance throughout their service life. Long spans are possible without the need for bracing, and built-in connections make them easier and quicker to erect. When maintenance is needed, contractors have open access to the ceiling, making their jobs easier. Lighter weight means easier handling onsite. This results in a reduced need for onsite labor, not to mention lower construction costs.

“It’s faster erection, it’s safer, and with galvanized steel, the life expectancy is over 90 years,” says Joe Buntyn, New Millennium’s eastern U.S. sales manager. “Your columns with steel are smaller, your footings are smaller, and it’s still easier to expand. You can go up with steel more easily than with concrete.”

John Barnett is principal, strategic services, with Centrifuge Brand Marketing. He can be reached at john@centrifuge-now.com or 708.469.7850.

TPP-2013-10-Open Possibilities

Goregous Green

TPP-2013-10-Goregous GreenBy Roy Diez

New garage decks are obviously developed to fill a perceived need for additional parking in a given area. The bet is that, as in the movie “Field of Dreams”, if you build it, they will come. Mixed-use structures hedge that bet by combining supply and much of the demand in one package.

Located in the fashionable Southtown area of Minneapolis, the MoZaic mixed-use project stacks six floors of structured parking on top of ground floor retail and restaurant space, and tops it off with three floors of offices. The 10-story structure contains 13,000 square feet of restaurant space on the ground floor, 556 parking stalls on the second through seventh floors, and 65,000 square feet of Class A office space on the top three floors. The parking levels are disguised by a six-story, vertical grow wall that’s billed as the largest green wall in Minnesota.

They Will Come
The synergy created by mixed uses is the formula for success. It’s cyclical: Having retail and parking handy attracts office tenants and restaurant customers who, in turn, provide much of the clientele for the parking spaces. Placing the offices on the top floors of the structure provides fabulous views of downtown Minneapolis and the lakes and was a major factor in attracting office tenants; this jumpstarted the synergy process. To make the whole package architecturally appealing, an art park with connections to nearby green trails was constructed in front of the building, and the giant green wall was added to the building’s front to mask the parking deck.

“The mixed-use design was conceived with the understanding that the building would be displacing parking by infilling an existing parking lot,” says Mark Harris, managing architect with the BKV Group. “There also was an obvious need for parking in the area. In addition to parking for the offices, the deck also services the parking needs of the [ground floor] restaurants and the neighborhood.” While there is no physical separation, the upper levels of the deck are designed for the office clientele with separate key card control in the elevator lobby. Public parking, operated by Loop Parking Company, Minneapolis, features automated ticket and pay stations.

“Our design vision for MoZaic was centered on three goals,” explains Joanna Hicks, senior vice president of project owner The Ackerberg Group of Minneapolis. “First, we wanted to solve the parking shortage in the area that was a concern to nearby residents by providing sufficient parking to handle peak load times. Second, we wanted to create retail to bring energy to our plaza. And third, we wanted to add daytime population to the area, create a more balanced local economy, and provide demand for the goods and services of the retail and restaurant establishments beyond just nighttime and weekend traffic.”

The Green Wall
The 60- by 90-foot-long green wall is flanked by a decorative custom-perforated metal screen and faces a 20,000 square-foot, ground-level plaza and art park at the building entrance.

Construction of the mixed-use building consisted of precast concrete spandrel panels and precast architectural cladding from Hanson Structural Precast. These are set on a post-tensioned, cast-in-place structural system and reinforced concrete foundation. Shear forces are transferred to vertical elements in the structure, including the heated elevator core and stair tower constructed with Hanson precast insulated wall panels.

Office floors feature floor-to-ceiling glass with floors separated by four-foot-high horizontal, precast spandrels. In the garage, the spandrels are only at even numbered floors and are slimmed down to two feet, eight inches high. The other garage floors are set back. Floor height at the first level of parking is nine feet, nine inches to accommodate accessible parking. On the other parking levels, the floor height is eight feet, nine inches.

“To accommodate the green wall, the post-tensioned floor slabs at levels two, four, and six cantilever out above the plaza below,” explains Harris. “Planter beds are located in these areas. Pre-manufactured four-inch-deep gridded mesh grow screens are clipped to the structure directly above the planter beds. Various species of vines are planted in these beds, extending vertically onto the grow screens. To accommodate drainage, the cantilevered slabs are insulated and waterproofed. The planter beds are filled with lightweight soil with an irrigation drip. Drainage for the planter beds is accommodated through weeps back into the parking garage.”

The large public plaza in front of the building contains benches, plantings, statues, a sculptured-art water fountain, and such fun objects as an 11-foot-tall clay human head, a giant blue arrow, and a reproduction of an old streetcar. Adjacent to the building and accessed from the art park plaza is the historic Midtown Greenway, which is an abandoned railway converted to a bike and pedestrian trail. To capitalize on this feature, the MoZaic plaza features both a ramp down to the greenway and a pedestrian bridge over it, connecting the building with neighborhoods to the north that had been cut off from the site.

Placing an unheated parking garage between two enclosed heated spaces (office and restaurant) presented obvious challenges to the design of the thermal envelope, says architect Harris. “The challenge was how to best address the atypical situation of an unheated second floor parking deck located directly above the tempered restaurant spaces. The last thing we wanted with the wild fluctuations in temperature in Minneapolis was to have the slab above the restaurants sweat with condensation. The question was how to best insulate the restaurant ceilings. This was handled with a closed cell, foam insulation product that contains an inherent vapor barrier. Use of the foam insulation product required prior review and approval from the City of Minneapolis. Concerns related to fire and flame spread were addressed with a fire-resistant intumescent coating.”

The interface with the office space was handled differently. There is a suspended, exterior-grade acoustic ceiling above the upper deck of the parking garage. The space above that—between the ceiling and the first floor of offices—is mechanically tempered. This approach addressed the concerns related to thermal performance while also providing a warm floor for the office tenants.

Another challenge, adds Harris, was meeting building code and zoning requirements that seemed somewhat at odds. The code has strict exterior envelope openness requirements to ensure ventilation of open parking garages “At the garage, there are both the horizontal spandrel panels and vertical infill panels which had to be taken into account,” Harris explains. “Additionally, we had to assume a certain percentage of openness for the green wall and review that with the city. Finally, there were strict requirements as part of the planned unit development (PUD) because the surrounding neighbors were concerned about the impact of headlights in the evening. To solve this issue, perforated metal panels were installed between the precast panels designed to obscure vehicle headlights as people pull into parking stalls.”
The Ackerberg Group, which specializes in urban, infill, mixed-use projects, is currently working on plans for a second building to be built on the site’s remaining 116-stall, surface parking lot. The plan calls for a 150,000 square foot building with offices and retail that would include two-levels of parking with 720 stalls underneath the building. Construction is scheduled for 2014.

Roy Diez is executive vice president of JOA, Inc. He can be reached at roydiez@att.net.

TPP-2013-10-Goregous Green

Parking Reform Made Easy

TPP-2013-10-Parking Reform Made EasyBy Richard W. Willson

In his new book, Parking Reform Made Easy, Richard W. Willson, professor and chair of the department of urban and regional planning, California State Polytechnic University, Pomona, argues that minimum parking requirements are outdated and unnecessary. After all, he says, they offer each person’s car a space at home, work, the grocery store, and the movie theater even though it only needs one at a time. To make the most of our cities and develop a transportation system that works for everyone, he says, parking reform is necessary.

The book offers guidelines on creating parking requirements that make sense in terms of future trends, along with a toolkit to revisit outdated requirements. It also includes guidance on working within political environments to reform parking and transportation.

Willson recently talked with The Parking Professional about parking reform, why minimum requirements may have passed their prime, and where it all goes from here.

The Parking Professional: Why did you write this book?

Richard Willson: I’ve been doing parking analysis for 25 years as a consultant and professor and practitioner. I keep encountering local jurisdictions and developers who were wrangling over the question of how much parking should be provided, and what new requirements should say about parking.

Donald Shoup, Ph.D.’s book, The High Cost of Free Parking, had a big effect on my thinking. His desired prescription is that cities make parking market-based and get rid of minimum requirements. In the core of some big cities, that’s what’s happening. But in smaller cities, they’re not ready to get rid of requirements and base parking on pricing alone.

A lot of developers hire consultants and go to planning commissions with their parking plans, and somebody says, “Where did you get this number?” I want to help empower local community folks to reform minimum parking requirements. The book provides a process on what to do and how to go in front of a city council and explain how it will work.

TPP: You pose the question of whether we should eliminate or reform parking minimums. Ideally, which would it be?

RW: I really think it depends on context. In core areas with mixed-use areas, deregulation is the right answer. In lower-density communities, however, it’s politically impossible.

I’m an incrementalist at heart. I think cities should start reforming, and oftentimes that means lowering minimum parking requirements. At some point in the future, they may get to the point of deregulating it entirely.

Ultimately, I would prefer a market-based parking supply system. In the book,
there’s an image of a suburban shopping mall in the suburbs with an arena next to it. Even conforming to minimum parking requirements, you can see that it’s a big waste of land. That’s kind of obvious to people. And in urban areas, parking requirements are standing in the way of economic development. If a city requires 10 spaces per 1,000 square feet for restaurants in an historic area, no one can find that land. So inadvertently, that’s preventing restaurants from developing. You end up with land waste in suburban areas and stifled development downtown.

We talk about the history of parking starting in the 1940s and 1950s, when the influx of the car necessitated parking requirements to be outlined. Experts now say we’re facing a time when fewer cars will be on the road, as the Millenial and other generations reject single-owner vehicles as a norm. What will that mean for parking policy if it comes to fruition?

RW: A chapter in the book deals with the irony that land use planners make their plans to look 20 to 40 years into the future, but they do that by looking at demographics from the past. When cities use parking utilization data from standard sources, they’re looking backward.

I think there’s a big change in perception that shows up in the numbers of 16-year-olds getting driver’s licenses. We need to recognize those social and demographic changes. If the building is going to last 50 years, we should use a future-oriented parking requirement for it rather than one that’s based on looking at the past.

The car-sharing phenomenon we’re seeing now and real-time carpooling are examples of a whole bunch of ways technology may allow the next generation to have lower vehicle ownership than what we’re all used to. Of course, if you’re designing sites and districts so they can share parking and a site builds too much, it’s less of a concern—they’ll share it with future development. If everything’s isolated from everything else, that’s just waste.

TPP: You mention several cities, including Philadelphia, Portland, Ore., and Vancouver, that are working on parking codes that support livability. What are they doing that other cities might want to imitate?

Portland eliminated its parking requirements as an experiment in multifamily residential and some other areas. They’re getting pushback on that. There may be a process there of getting to the very right point of things. Portland has been in the forefront of lowering parking requirements and eliminating them in some cases.

Philadelphia did a comprehensive code revision and a lot of big cities are doing the same thing—Denver is doing it, and Los Angeles is doing it right now. This is an opportunity to better connect parking requirements with community goals and other zoning provisions—to say, “What is the kind of district we’re trying to create, and how does the parking support those specific goals?” As a result, their requirements are much easier to read, simplified, and in some cases, lowered.

Vancouver is a city that’s done a lot of transit development and land use planning. They are deliberately pursuing a very multimodal transportation system. Parking is part of that.

TPP: There’s a relatively new trend, particularly in downtown multifamily housing, to not require any parking. Does that ever make sense or ever completely not make sense?

RW: The problem in the past was that we had these uniform rules. My mantra is that we should get away from the universals.

I’m working with a developer in downtown Los Angeles right now, and the city is getting ready to get out of the way—it’s not telling the developer how much parking to build. The developer, though, still faces the question of whether it’s a market risk to build his building without any parking. Sometimes it is, and sometimes it isn’t. If a developer is leasing or making arrangements for shared parking with adjacent or nearby properties, it make sense as long as the developer is convinced that there’s no marketing risk to having no parking onsite. This kind of practice creates a demand for shared-use parking facilities.

A student of mine moved to Cleveland awhile back and rented an apartment. She had six or seven options on parking. There was a certain price if she wanted a space dedicated just to her. There was another price if she wanted the right to hunt for a space in the facility that would occasionally be affected by special events. There was a difference in price based on how far she wanted to walk from a space.

What I notice in big downtowns is that people aren’t using their cars every day, but they still want to own one. So there’s a market for parking that offers access two or three times per week. Let’s leave it up to the market. What is the justification of a public agency forcing a developer to build more? I’m not anti-parking by any stretch, but if the market supports that, by all means, it should be used.

TPP: There’s a difference in real-world parking requirements among businesses: a hot dog stand vs. a prix fixe restaurant; a loft condo building vs. one that attracts older, retired residents. How flexible should minimum parking requirements be?

RW: That is exactly what makes cities nervous about lowering parking requirements. Part of what’s happening in some areas is a move to a more blended rate approach, where individual uses will vary in terms of requirements. The book offers a parking management toolkit that helps people work through parking demand that may be higher or lower for a particular use or that may be shared, which lets you respond when the demand is different than what you anticipated. I think our cities’ approach has been “set it and forget it.” Get the requirements right, set the lot fees, and don’t worry about it after that. We’re moving towards a managed approach where you build parking after doing studies and after figuring out pricing. It’s when you really see the true demand for parking, and not just relying on zoning.

TPP: What about dense cities such as Boston vs. those with more room such as Boise, Idaho. Should they follow different models?

RW: I really think so. My daughter went to school in Boston. She wanted to buy an air conditioner for her apartment. So we walked to the hardware store and gave them a driver’s license, and they gave us a dolly and we walked the air conditioner back to the apartment and then returned their cart. This idea that you need a car to buy an air conditioner is totally not true, at least in Boston. That probably wouldn’t be true in a smaller city with less density. We have communities working towards mixed use and walkability, but it takes decades to do that.

We need to overcome this idea of rounding up, which is when you really think the use will be 2.4 spaces to 1,000 feet and you round up to three spaces. It’s rounded up instead of using a more analytically-based, policy-based system. That’s what we need if we’re going to have these regulations at all.

TPP: Where do we go from here?

I’m hoping elected officials will hear about the book and that planners will read it. I sometimes meet with local planners and ask if they have issues with minimum parking requirements, and all their hands go up. I hope big cities will do comprehensive rewrites, and that others will start with the most pressing issues, whether they are restaurants in downtown or offices in the suburbs where there are empty lots. Start there. Make some changes and show that the world doesn’t end if changes occur. Then, you can work on it incrementally.

Richard W. Willson’s new book, Parking Reform Made Easy, is available from IPI’s Amazon.com store. Visit it at parking.org/bookstore.

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Dispensing the Future

TPP-2013-10-Dispensing the FutureBy Kim Fernandez

It’s not often one can win an architecture award for a structure that hasn’t been built, but that’s exactly what Boston firm Moskow Linn Architects did a few years ago. Better yet, they did it with a parking garage.

This wasn’t any parking garage, mind you. The structure they designed took its inspiration from a Pez dispenser—the little plastic toys that spit out candies when their hinged tops are pulled back. It was designed to improve city living both in its award-winning design and its purpose, which was to dispense shared cars on-demand to members of Zipcar in cities such as Boston and Washington, D.C., where downtown real estate comes at a premium and buildings tend to go up instead of out.

The concept was relatively simple: shared cars would stack in a single column on robotic platforms. Car share members would swipe their cards in a machine at the ground level and be dispensed vehicles, one at a time. Returning the cars would work in just the opposite way: a card would be swiped, the vehicle would enter the garage, and the platform would rise, making room for another car below. On paper, it makes sense: it saves valuable real estate, it’s cost-effective, it’s environmentally-friendly and efficient, and its striking design serves as a constant visible reminder of the car sharing company to those driving and walking past.

Keith Moskow and Robert Linn, principals of the architecture firm that dreamed up the Pez dispenser garage, had high hopes for it—at the time, the common car share model was that companies would stock only one kind of vehicle, and it wouldn’t matter which car an individual member was dispensed. As with many revolutionary ideas, though, a speed bump appeared. Car sharing providers expanded their horizons and began stocking different cars from which their members could choose, from hybrids to luxury sedans and SUVs.

That seemed to sound the death knell for the Pez dispenser garage. After all, with a single column of robotic platforms, customers would be forced to accept the next car in the stack when they swiped their cards. The concept languished in the Moskow Linn offices, buried at times beneath buildings and ideas that actually came to fruition.

But things have changed again, as they often do, and those who claim to be ahead of the curve technology-wise say the single-car sharing model may not be a dinosaur after all. In fact, they say, city dwellers may soon rely on single-model pod-type vehicles to get around: they’re clean, they’re efficient, and they’re easy to park, with some taking only one-third the curb space our current cars require.

And so the vehicle Pez dispenser may well be dusted off and reconsidered, and perhaps even constructed in a city near you in the not too distant future. Its designers say they’d be thrilled to see that happen and that its parking model embodies everything they hope to accomplish: create more forward-thinking, sustainable, and livable cities through innovative design.

The Idea

“We are always thinking about city living,” says Moskow from his Boston office. To him and partner Linn, finding garage inspiration in a children’s candy dispenser isn’t anything out of the ordinary.

“We have a limited number of parking spaces in Boston,” says Linn. “We started brainstorming how to use some of the leftover pieces of the city, and how we could take space that holds one or two cars and fit seven or eight instead. The genesis of the idea was that we realized there’s no way to do that cost-effectively unless you use a non-sorting system.”

The two envisioned stacking cars in a tube, the same way Pez candies are stacked in their dispensers, only flipped upside-down. Instead of bending back the head of Darth Vader or Mickey Mouse to get a sweet treat, drivers would request a car at the bottom and have it dispensed the same way as the candy: by popping out of the garage.

Research seemed promising. “We used a simple stacker crane—the same thing you’d use in a warehouse,” he says. “It only costs about $30,000. It’s very cost-effective.” They drew up designs for their tall, narrow dispenser and realized even more potential.

“The beauty of this is that a stack of their cars would become advertising for the car sharing company,” says Moskow. “You’d see this linear stack and wonder what the heck it was, and then you’d realize it was for Zipcar.”

They developed a protective enclosure for the dispenser that could also hold actual advertising on it. In their drawings, the translucent scrim moves up and down as cars are dispensed, lowering to protect pedestrians as cars enter and exit, and raising again to shield the stacked vehicles inside and serve as a sort of billboard. “It could be self-financing,” says Moskow.

The hitch, of course, is that the dispenser as designed would require the car sharing company to only house one type of car; originally designed for Volkswagen Beetles, it could be modified for any model, but limited to only one.

“It only works if it’s a single stack,” says Moskow. “It doesn’t matter which car you get if they’re all the same. It would be perfect for a car rental company that only had one kind of car, which actually could be a model for a company—the Jet Blue of car rentals.”

While that was the original thought for car sharing, that industry morphed to give customers more choice, giving the industry greater reach. The Pez dispenser wasn’t built. But that doesn’t mean Moskow and Linn have given up hope.

Moskow says the Pez dispenser garage served as a catalyst for a lot of conversations in the parking and other industries about what was possible, even when space was tight, when the goal was improving livability downtown.

Looking ahead, they say the garage is still a viable idea, particularly as members of the Millennial generation and those younger eschew individual car ownership in favor of mass transit and car sharing when they need their own wheels. And technology is finally catching up to the design they sketched out back in 2003.
“In 10 years, the idea of swiping and operating something has become much more prevalent,” says Linn. “Ten years ago, no one was checking in at the airport by themselves. No one was checking out at CVS by themselves, or at the grocery store, or at Home Depot. It’s part of a trend. We didn’t know that when we came up with this, but we’ve embraced a self-serve model of consumerism, and perhaps this garage becomes a model.”

Linn agrees, and can envision morphing the original garage idea into something that better serves specific populations. “There’s a movement right now that looks sort of like a big drying rack, but it’s for bicycles,” he says. “People want to get their bikes off the ground for storage. So maybe that’s where this works, but it also creates an architectural element that heightens awareness of alternative modes of transportation. It’s a different approach to bicycles, but in the same family as the way we think about cars.”

Even for cars, the garage may have simply been ahead of its time. If the concept of shared cars really takes off in crowded cities, experts say they likely will not be the Toyotas and Chevrolets we think of as being small now. Instead, drivers may well embrace micro-cars, such as the Fonseca EMO concept car. It actually changes shape as it’s driven, going from an upright smaller vehicle when parked to a flattened-out, wider shape as speed increases. Consider the URBAN.POD, which is a one- to two-seater vehicle that offers sensors to avoid crashes and takes up much less space on the street than currently produced consumer vehicles. Then there’s the concept EN-V from General Motors, which is a tiny electric car that can link up with others to form a sort of train, saving energy and road space, and letting drivers break off the chain when they reach their destinations. All of these would be candidates for housing in the Pez dispenser garage—it may just be a bit ahead of its time.

“In a lot of ways, I think it’s nice to make parking different,” says Linn. “You’d get more people taking public transportation to get in and out of the city, which makes the city more pedestrian-friendly and feeling like a better, quality space.”

That said, he’s realistic. “There is always going to be a need for people to drive downtown,” he says. “Having a parking alternative that gives you a way to drive a car in and park and be cost-effective is important.”

Kim Fernandez is editor of The Parking Professional. She can be reached at fernandez@parking.org.

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Psychological Contract vs. Employee Engagement

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By Julius E. Rhodes, SPHR

When I was a child and my dad worked in the stockyards of Chicago, he often said, “Son, get a job where you can build a good career, stay for 50 years, and then retire.”

After I completed graduate school and started to explore various job options (I believe I was on my third job in less than 10 years) my father said, “I hope no one pays you a nickel more, because if they do, you’re gone. What you need to do is stay with one company for 50 years.” I replied, “Employers today don’t want you for 50 years and if they do, they may not value you the way they should. Besides, it’s not about money. It’s about the connection that you can build with an organization.”

In order for a contract to be valid, there must be offer, consideration, and acceptance. When you propose to someone, the offer is marriage; the consideration is the ring; and the acceptance leads to a wedding. “To death do us part” is an implied—if not explicit—lifetime contract.

There is an implied psychological contract between employers and employees—it’s what my father and I were really talking about way back when. My father’s generation operated under the assumptions that they would be provided with a lifetime career in exchange for their loyalty; that they would be given a fair day’s wages for a fair day’s work; and that employers would act in the best interest of their organizations with a focus on their employees.

Today, we see rising concern about individuals wanting to work for organizations that communicate effectively, have positive and caring attitudes towards their employees, and understand the need for individuals to live balanced lives. There is greater emphasis on fulfilling intrinsic notions of providing challenging work, having a sense of pride in the organization and the products and services it delivers, opportunity for advancement, and reasonable stress levels and working relationships. These areas are much more vital than extrinsic rewards, which typically take the form of compensation. By itself, salary has never really been a predictor of employee satisfaction or productivity.

The point I am trying to make is that whether you look at the psychological contract of previous generations or current thinking about employee engagement, the reality is that both served or serve a vital purpose in making our workplace what it is today and what it can be tomorrow.

I believe there are aspects of the psychological contact that are still applicable in today’s workplace, including equity, trust, commitment, well-being, and performance. In addition there are aspects of employee engagement that not only fit this model, but expand on it. Neither construct can stand on its own if we are to develop truly humanistic approaches towards valuing employee contributions in making our organizations the best they can be, and offering them in return the opportunity to live balanced enriching lives.

There is a balance to be had in the employer/employee relationship, and we all must do our part to synergistically achieve our goals.

Julius E. Rhodes, SPHR, is the founder and principal of the mpr group and the author of BRAND: YOU, Personal Branding for Success in Life and Business. He can be reached at jrhodes@mprgroup.info or 773.548.8037.

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Parking Garages and Green Walls

TPP-2013-10-Parking Garages and Green WallsBy Isaiah Mouw, CAPP, LEED Green Associate

We have all seen our share of bland, unappealing parking garages. Unfortunately, many of us have had a hand in designing them as well. One may point out the obvious: that the primary goal of the parking garage is to simply park cars. We will not argue this point; however most parking garages are located in the heart of urban communities where architecture interoperability and smart growth mean everything.

The Parking Authority of River City, Louisville, Ky., and CITY Properties Group wanted to do something different when they designed the Clay Commons Garage and Glassworks Garage. One concept chosen that benefited these parking garages, both aesthetically and sustainably, was that of a green wall.

The concept of green walls is not new—it’s been around for more than 2,000 years, since the ancient Babylonians created the Hanging Gardens. As technology has evolved, so has our ability to simplify this process. Just look at the world’s largest vertical garden: installed at the Centro Commercial Fiordaliso mall in Milan, Italy, it measures 13,600 square feet and includes more than 44,000 plants, but was built in only 90 days.

Why Go Green
The benefits of green walls are numerous. They are aesthetically pleasing, which improves a customer’s overall experience. Many studies have linked the presence of plants to improved human health and mental well-being. Aesthetically pleasing and sustainable features always improve the marketing of a garage. Green walls keep patrons’ vehicles cool on hot summer days while reducing the heat island effect. They also deter graffiti and reduce noise by serving as soundproof barriers. The most important benefit is the improvement of air quality, as green walls capture air pollutants and filter contaminates.

At Republic Parking System, we recommend involving a landscaping professional during the installation process. It is most important to choose a native or adaptive plant species that will thrive in the given climate conditions.

There are several types of the green façade systems typically used in designing a green wall to choose from; the cable and wire rope net system and the modular trellis panel system are the most popular. The cable and wire rope system uses steel cables to support faster-growing plants, and wire nets with closer intervals to support slower growing plants. In Louisville, we chose the modular trellis plant system, which is a rigid fence-like panel made from steel wire that supports the plants without sacrificing the integrity of the parking garage building membrane.

Once the green walls grow to complete coverage, a typical parking maintenance employee can keep up with the maintenance of the green wall after some brief training from a landscape professional. Usually, watering and pruning the plant and periodically inspecting the cable or panel system is all that is needed. Green walls typically take between three and five years before reaching full coverage and we are completing our second year. See p. 32 for another example of a garage with a green wall.

Does your operation have any issues with graffiti? Is your municipality looking to decrease its urban heat island? Is your parking operation looking for Green Garage Certification points? Is your parking facility looking for an aesthetically pleasing façade or marketing advantage? If you answered yes to any of these questions, consider contacting your parking consultant or local landscaping professional to discuss what a green wall can do for your parking operation. Our green walls cost an initial investment and time to develop, but we are excited to see the final result and contribute to the community’s character and sustainable goals.

Isaiah Mouw, CAPP, LEED Green Associate, is a general manager for Republic Parking System and a member of IPI’s Sustainability Committee. He can be reached at imouw@republicparking.com or 502.574.1497.

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How Much does a Structure Cost

TPP-2013-10-How Much does a Structure Cost
By H. Dean Penny, PE

How much barbecue do you need to feed a group of 30? How many cookies will this recipe make? How many drinks are in a pitcher?

Have you ever tried to accurately answer a question that had more than one possible answer? In each of the questions above, a short answer provides the distinct possibility of error: over-estimate and end up with waste; under-estimate and end up with a bunch of hungry, thirsty, and angry guests. Either result is less than ideal.

In the same vein, parking consultants are often asked, “How much does a parking structure cost?” Overstate, and you may kill the project or lose the opportunity. Understate, and your client may commit to a project only to discover that actual costs are drastically more than anticipated. Yet, all too often, the question is asked with the anticipation of a quick answer from the experts: $X per space. A project is being contemplated, and a rough order of magnitude answer is needed to decide whether or not a parking structure is a feasible alternative. A quick answer is desired, but the correct answer requires more information. Only the experts really understand that.

Although people often think of costs in terms of dollars per space, many factors affect the cost of a parking structure. We build square footage with the goal of using it for parking. Therefore, the cost of a parking space is a product of parking efficiency (square feet per space) and structure efficiency (dollars per square foot). Each component plays a critical role in determining the ultimate cost of a parking facility.

Parking efficiency is the total gross area of a parking structure, inclusive of stairs, elevators, and all parking floors, divided by the number of spaces. Typical parking efficiency for an above ground, stand-alone garage is 300 to 350 square feet per space. Many below-grade or mixed-use garages can have parking efficiencies of 400 to 500 square feet per space. Factors that affect parking efficiency include:

Footprint. Does the module width allow double-loaded parking bays for every bay? Is the length enough to allow parking on each end and on parkable ramps?

Mixed-Use. Are areas required for uses other than parking?
Functional Layout. What are the layout needs: two-way 90-degree parking versus one-way angled parking? Parkable ramps versus speed ramps?

Column grid. Is the layout a short-span column grid where parking spaces are between columns, or a long-span column grid where parking aisles and spaces are free of columns?

Structural efficiency is a measure of the total construction cost divided by the total area of the structure, including stairs, elevators, ramps, and all parking areas. This is consistent with the way other market sectors compare construction costs, expressed in dollars per square foot. The average structural cost for a parking structure varies with geographic market and can range from $35 per square foot to as much as $65 per square foot. Factors that can affect structural efficiency include:

  • Geographic/construction market
  • Mixed use versus stand alone
  • Above ground versus below ground
  • Topography
  • Structure framing type
  • Mechanical ventilation vs. natural ventilation
  • Fire protection: dry standpipes vs. sprinkler systems
  • Architectural enhancements

In the end, most owners budget for parking in terms of dollars per space. However, to be as accurate as possible, it is best to understand the project in terms of parking efficiency as well as structural efficiency. Design decisions that enhance parking efficiency can often help make a project financially feasible. When in doubt, consult a parking specialist!

H. Dean Penny, PE, is principal with Kimley-Horn and Associates and a member of IPI’s Consultants Committee. He can be reached at dean.penny@kimley-horn.com or 919.677.2090.

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