Boasting improved aesthetics and reliable design/construction costs, metal building systems retain their appeal in specific retail developments.

Pre-engineered metal building systems have come a long way since they emerged in the late 1940s. They gained recognition within the shopping center industry during the explosion of outlet mall development in the 1980s, and they continue to evolve to effect a broader range of retail applications.

In their most basic form, metal building systems consist of a series of integrated, often computer-designed components (i.e., roof and exterior wall systems). The systems are factory-fabricated and are shipped to a job site ready for assembly and erection by a local builder or contractor.

As they were in the early years, price and construction time are often cited as the most attractive features of metal building systems. Aesthetic enhancements, design flexibility and reduced maintenance costs have added to the appeal.

Within the retail industry, metal building sales have remained consistent -- "from year to year, within a percentage point," says Charles M. Stockinger, general manager for Metal Building Manufacturers Association (MBMA), Cleveland. Retail accounted for only 8 percent of total combined sales for metal buildings in 1996.

That 8 percent translates into millions of dollars, notes Stockinger, adding that MBMA's member firms account for nearly 80 percent of all metal building shipments. In 1996, MBMA member firms sold approximately $185 million of product to retail developers, he says.

Growth of metal building systems within the shopping center industry is limited by lingering perceptions of early systems, says Stockinger. Shopping center developers "relate to an image of metal building systems as they were years ago," he explains.

Today's metal building systems offer developers a variety of construction options, says W. Lee Shoemaker, MBMA director. For example, metal systems may be integrated with other exterior architectural materials such as precast concrete, brick, stone, wood and glass.

Similarly, the roof profile can appear flat, gently sloped or steeply inclined. Shoemaker also notes that interior areas may be segmented or expansive; they may be open or contain columns; and they may be finished or unfinished.

"Aesthetically, pre-engineered [construction] can look just as nice as conventional construction," confirms Jim Whitcome, senior vice president of capital services for The Mills Corp., Arlington, Va.

The standing advantages Although aesthetic improvements are gaining attention, the major benefits of pre-engineered building systems appear to be unchanged. Construction time and cost-effectiveness remain at the top of the list.

Typically, the time required to "construct" a pre-engineered building system is one-third less than that required for traditional construction, says Shoemaker. He notes that in-plant technology and production processes measurably reduce on-site labor demands.

Furthermore, since most metal building systems are computer-designed, the time and costs associated with traditional design methods also can be reduced. "That translates into dollars [saved] for the owners," says George King, MBMA chairman and chief executive officer for Portland, Tenn.-based Associated Building Systems.

The building systems also offer savings through reduced maintenance costs and improved energy efficiency, says Shoemaker. For example, many of the maintenance problems associated with traditional construction (e.g., structural deterioration, cracking, damp rot and insect damage) are reduced or eliminated with the long-life materials and finishes used in metal building construction, he explains.

Additionally, the advent of standing seam metal roofs has gone a long way toward making metal building systems more energy-efficient. They accommodate expansion and contraction, as well as a variety of insulation types. As a result, "standing seam roofs have become widely used in retail applications," Shoemaker says.

Apples to apples The cost and performance differences between pre-engineered and conventionally constructed shopping centers can be illustrated by comparing both methods for a single center. Highland Place, a 20,000 sq. ft. center in Baton Rouge, La., was completed recently by B.J. Couvillion Inc., Baton Rouge.

Brent Couvillion, president for B.J. Couvillion, notes that his company has experience building conventionally constructed shopping centers as well as pre-engineered ones. Highland Place was built using a metal building system.

The project included the shell building as well as parking and site improvements, but it did not include tenant finish-out, notes Couvillion. It was completed in six months at a cost of $650,000. To build the same center using conventional construction, Couvillion estimates the project would take two more months to complete and would cost 15 percent to 18 percent more.

Stuart Taylor, vice president and project manager for Kenbridge Construction Co., Kenbridge, Va., reports similar comparisons for 14,256 sq. ft. South Hill Shopping Center in South Hill, Va. With a metal building system, the project was completed in fewer than 90 days at a cost of $430,000 (slightly more than $30 per sq. ft.). Taylor expects that the same center built conventionally would have required two more months for construction and cost approximately 10 percent more.

Couvillion says a reflective coating on metal building systems improves the structures' energy efficiency. Furthermore, Couvillion and Taylor note that energy costs can be reduced with pre-engineered systems because they are capable of accommodating 6 in. to 8 in. of insulation between the structure and the roof. Whitcome, on the other hand, says conventionally built structures can be insulated just as well as the pre-engineered systems.

In addition to containing energy costs, metal building systems reduce maintenance costs, says Couvillion. Costs for pre-engineered buildings are "definitely cheaper" than they are for conventionally built buildings, he says, adding that manufacturers' warranties are a contributing factor.

Couvillion notes that Highland Place's standing seam metal roof comes with a 20-year warranty. Had the center used a built-up or single-ply roof in conventional construction, the lifecycle of the roof would have been eight to 11 years, he adds.

The standing seam metal roof is a "legitimate 20-year system," Couvillion says. "It is far superior to built-up or single-ply roofs and other types of conventional roofs."

A look at limitations Despite enthusiasm from manufacturers, contractors and developers, metal building systems do have limitations that prevent them from becoming more widely used in the shopping center industry. For example, the systems are designed for low-rise facilities, which rules out their use in multiple-story or vertical shopping center construction.

The Mills Corp., which once used pre-engineered metal building systems in new construction, now builds all of its centers conventionally. Whitcome, who is complimentary regarding the changing aesthetics of metal buildings, notes that Mills opts for conventional construction for three reasons:

Pre-engineered buildings are limited in their flexibility. For example, Whitcome says point loads are not known until late in a project; with metal buildings, changes at late stages could result in delays and additional costs.

The use of a single vendor for the centers' structures did not afford Mills the savings that comes through competition.

After completing several pre-engineered projects, Mills executives decided that development could be handled in-house more efficiently and less expensively.

Developers also note that flexibility issues come into question at the tenant finish-out stage. If the size of a tenant space changes throughout the course of negotiations, the change can affect HVAC requirements.

In turn, the changing requirements can affect the load capacity of the center's steel structure. With a pre-engineered system, the developer is already committed to certain load requirements, making it difficult and sometimes costly to accommodate last-minute changes.

Creating new perceptions Although metal building systems may not be ideal for all shopping centers, developers are continuing to use them and benefit from them in strip center settings. "I think the outlook is very favorable [in that market]," says King.

MBMA is further enhancing its "metal building as erector set" image by instituting a quality certification program. It requires all association members to become certified according to standards set by the American Institute of Steel Construction. Certification attests to third-party examination of engineering and manufacturing policies, as well as to quality assurance standards.

"This program will go a long way to improve the product going into the marketplace as well as to improve our image," says King.

"This will continue to elevate the quality of our industry," Shoemaker adds, noting that the certification will join construction time and cost-efficiency as "selling points" to enhance growth.

Allyson Sicard is an Atlanta-based freelance writer and a former managing editor of Shopping Center World.

Butler Manufacturing Co. The MR-24(R) roof system from Kansas City, Mo.-based Butler Manufacturing Co. consist of panels joined with a double-lock standing seam. A clip formed into the seam attaches to purlins.

Structures Unlimited Inc. Translucent structures from Manchester, N.H.-based Structures Unlimited Inc. combine flat or curved structural composite sandwich panels with a pre-engineered aluminum structural system. The substructure spans areas up to 100 ft.

Metallic Building Co. WeatherRoof II metal, standing seam roofing panels from Houston-based Metallic Building Co. attach to sub-framing with concealed, interlocking clips. Endlaps are connected by a compression joint, and sidelaps contain a pre-applied sealant.

Ceco Building Systems The Cecolok(R) CLP standing seam roof system from Columbus, Mo.-based Ceco Building Systems has 30" wide interlocking panels that attach to the substructure with concealed fastening clips. Panels are joined with a double-lock seam and a 2" intermediate rib. They are available in a variety of finishes.

American Buildings Co. Shadow panels from Eufaula, Ala.-based American Buildings Co. have a deep-fluted profile that creates contrasting shadow patterns and conceals fasteners. They attach inside framework, have 16" coverage, and are available in 24 gauge embossed finish.

Corle Building Systems The LokSeam standing seam roof system from Claysburg, Pa.-based Corle Building Systems is designed for transitions from roof to fascia. Panels are made from cold-rolled sheet steel and are available in 22, 24 or 26 gauge. They range from 10" to 18" in length, are installed with concealed fastening clips, and are available in a variety of colors.

Star Building Systems Building systems from Oklahoma City, Okla.-based Star Building Systems are computer-designed and accept finishing materials from timber and stucco to concrete and brick.