Answers from an Architect on School Food Facilities
An interview with Steve Marshall, president of The Marshall Associates, Inc.
Steve Marshall is president of The Marshall Associates, Inc., a food service consulting and design firm based in Oakland, California. Since 1964, Steve has designed more than 5,000 kitchens for schools, hotels, resorts, restaurants, corporations, hospitals, prisons, military installations, and other organizations. He designed the first cook/chill facility in North America in 1976 and has designed more than 50 central kitchens for school districts around the country. Marshall was named Food Service Consultant of the Year by Food Equipment Specialist Magazine and one of America’s top 10 kitchen designers by Food Arts, the professional chefs’ magazine.
Center for Ecoliteracy: What is the ideal makeup of a planning team to begin a facilities planning process?
Steve Marshall: Every district’s situation is different, but I’ve found that a good planning team includes the district’s food service director, its business manager (the money source), and a facilities planning person (the construction and site location source). It’s always good to have a board member involved and the superintendent, or his or her representative. It’s nice to have a food consultant to advise the group. You don’t need an architect until you’ve decided to implement a plan.
CEL: Where does the planning team begin?
SM: By asking the right questions. The answers to those questions, along with a few rules of thumb, should enable the district to project its needs for facilities and equipment, estimate costs, and measure the district’s readiness to make the transition. The district should be able to estimate how much money it would need to raise (for example through a bond measure), without hiring an architect or other outside professional.
CEL: Once the team is in place, what are the first questions a district should ask?
SM: First, the district should determine its needs. How many meals does it project serving every day? What are the district’s enrollment and the level of participation in its meal programs? Are those likely to change? For instance, a California school district that projects increases of 300 students a year for the next 10 or 15 years needs to anticipate that growth when designing facilities.
The team should study recent community demographic trends and incorporate what they are suggesting about increases or decreases in the number of children eligible for subsidized lunches in the coming years into the planning process. The team should also run projections of how many students could be attracted to buy full-price lunches from the food service if improvements to service were made. The planning process needs to strike a balance between the quality of meals the district intends to serve and the needs and costs associated with that service. Then, the district needs to examine its goals for food service, because these will help determine the infrastructure requirements. Does the district want to serve as many students as quickly and cheaply as possible? Does food service need to turn a profit? Are prepackaged meals, frozen food, and convenience food acceptable? Or does the district intend to serve quality, fresh food, obtained to the greatest extent possible from sustainable local farms? The answers to these questions all carry implications. For example, preparing meals from scratch with fresh ingredients will probably require at least twice the kitchen space as serving preprocessed food does.
A district food policy can answer many questions about the food program’s goals and priorities. For example, before a school district begins discussing facilities, it might choose to adopt a nutrition policy that describes the intended direction its school meal program will follow. If, for example, the district concludes that it is moving away from frozen and processed food, and it incorporates that decision into its district policy, it is then prepared to discuss facilities. During the policy and planning phases, adequate attention should also be directed toward the student dining experience and the atmosphere of the dining environment.
CEL: If a school district has decided on, or is considering, serving fresh meals using locally sourced ingredients, what implications does that have for facilities design?
SM: There are, generally speaking, three primary models. First, there’s the central kitchen model from which food is transported to all the other schools in the district, whether that’s one other school or 40 others. The second model sites a kitchen at every school. A third model some districts are trying is a variation on these two, but these are the basic choices. The variation might site six "base" or hub kitchens throughout the district to serve 20 or 30 schools, but we have found that model to be inefficient. Even if the district has enough space for that many kitchens — and many don’t — to have six managers, and six bakers, or six cooks at each of six sites is cost prohibitive. A central kitchen might have six cooks, depending on shifts, but that would be serving the entire district. There is economy in scale.
Here’s one rule of thumb for estimating space needs. A minimal "fresh food" production kitchen to serve 200 meals up to 1,000 meals would be 1,000 square feet. Beyond 1,000 meals, add one square foot for each additional meal served (for example, 4,000 lunches requires a 4,000-square-foot kitchen). Even in very large kitchens, it actually scales up the same. We’ve designed central kitchens that serve 30,000 lunches, and they’re in the neighborhood of 30,000 to 35,000 square feet. A kitchen that was built as an original production kitchen for a high school or a middle school is likely to be in the 2,000 to 2,500-square-foot category. To go up to a 4,000-square-foot model, there’s a good chance you can find space to expand around the existing building. As you move to an 8,000–square-foot model, I doubt if there’s that kind of adjacent square footage available on most school sites.
CEL: What are the general parameters around remodeling an existing kitchen?
SM: Here’s another rule of thumb: building costs will be about $300 a square foot for remodeling ($150 for equipment, $150 for interior construction), while building a new kitchen will cost an additional $50 a square foot for the outer shell. If the building is a metal, pre-engineered structure (for example, a Butler Building), these types of structures usually are only allowed on maintenance yard sites. A kitchen shell building converted on a school site will require duplicate or similar school site materials, which will be $100 to $125 per square foot. Then you need to add another 20 percent for "soft costs" such as architects and engineers, permits, sewer hookups, inspectors’ fees, and so on. So there’s a definite cost savings in remodeling if you have enough space around an existing kitchen. I’ve provided drawings to suggest an efficient way to do that: move all the storage, including refrigerators and freezers, to the outside of the existing building. Then use the space freed up inside to expand the area available for food preparation.
The downside to expanding on an existing school site is that it’s typically in a residential neighborhood, invariably with houses just across the street. The neighbors may object to the visual expansion. Truck traffic will increase, probably fivefold. Instead of single purveyors delivering processed meals, often in quantities to last several days, many individual purveyors of fresh food will make deliveries at the kitchen door every morning. You must also add the impacts on neighborhood traffic of multiple district dispatch trucks leaving the kitchen to transport finished food to other school sites.
That’s why central kitchens are often located at corporation yards or other non-school sites in more industrial neighborhoods that already experience bus and truck traffic, and that don’t have adjacent residences. A central kitchen doesn’t necessarily need to be centrally located to the district. Once you’re on the road, delivering to one school after another, it doesn’t matter where you started. Any construction on a school site in California has to be approved by the Division of the State Architect (DSA). If construction is not on a school site, you don’t need to go to the DSA, which is concerned about structural and fire safety in buildings used by children. If the DSA is involved, you’ll need to pay its inspector $30,000, and there are all kinds of additional costs. But if it’s on a maintenance site or other non-school site, all you need are local building permits, which are much quicker to get — literally, three weeks versus nine months.
If you need to buy a site to build a central kitchen, unless you’re in a really rural area, that’s an expensive proposition. It’s much less costly to site the new construction on a maintenance yard. Occasionally, a district will solve the problem by purchasing a warehouse building in the industrial area of town and remodeling it into a central kitchen.
CEL: What decisions about delivery of food from a central kitchen affect facilities and equipment needs?
SM: There are really two distinct choices. The food can be prepackaged — meaning that every meal leaves the kitchen in a single-portion package. It usually goes out in two containers, one hot and one cold. The "hot" one still leaves the kitchen cold, but it’s rethermed like an airline meal at the satellite kitchen. Or, it can be sent in bulk — tote boxes of lettuce, sheet pans of pizza or lasagna, hotel pans of starch, rice, corn, etc., and then served in a traditional cafeteria style.
There are many reasons to conclude that bulk is better, but sometimes goals conflict, as when schools set a goal of serving high-quality food, but also set a goal of serving the most lunches in the shortest time. A whole pan of green beans or corn holds heat better than individual little portions, which have a tendency to get cold. All the solid waste from all those individual packages adds up. The bulk program is the desirable way to serve food, but it’s slower. During the planning phase, it is also important to consider improvements to the environment in which students are served, as well as the kitchen facilities used to prepare the food. Students are highly influenced by the school meal environment and often make decisions to eat, or not to eat, at school based on their experience of the dining room. Most elementary schools average 30- to 35-minute lunch breaks, and usually one lunch period. A 900-student school with 50 percent participation needs to serve 450 students, and the students need to eat in about 20 minutes. With elementary school students especially, they want to gobble lunch down as fast as they can, so they can get out and play, because the lunch break is also their recess.
A cafeteria line with any interplay at all, where the kids can make choices, takes time. In short order, the lunch line can begin to back out the door. One obvious way out of this dilemma would be to increase the length of the lunch period, but that idea often meets with resistance, for example, from administrators demanding more "instruction time," teachers and bus drivers not wanting to lengthen the school day, or business managers trying to minimize the food service staff’s hours.
CEL: What advice do you have about the charts, diagrams, and plans you have provided for this section, including generic drawings and equipment lists?
SM: I hope that the captions to the drawings will explain them clearly. Some of the equipment recommendations may need further investigation. Some pieces of equipment may cost more, but will pay for themselves in better-tasting, safer food and more efficient operations.
For example, a blast chiller is one of the most important pieces of equipment if food is to be cooked in a central kitchen and sent cold to satellite sites. Chilling quickly is more efficient; food doesn’t need to remain as long at the kitchen site. Chilling quickly is also best for food safety. A pan of chili can take up to 10 to 12 hours to cool from 180°F to 40°F; a blast chiller will cool the same amount in 1.5 to 2.5 hours, giving bacteria much less chance to develop.
For the central kitchen, I recommend roll-in rack ovens instead of conventional convection ovens. With a convection oven, you have to individually put each pan — whether it’s chicken or cookies — on every shelf, and then pull the pan out halfway through the cooking procedure and turn it around to get even cooking. A roll-in rack oven spins the rack, giving constant, even cooking. The ingredients from your prep area don’t have to be put onto a pan rack and then transferred from that to the oven. The whole rack rolls into the oven, and can be rolled from the oven into a blast chiller. The food never leaves that rack. That allows a person to prepare three times as many meals per labor hour. In a partially automated kitchen, that person can produce five times as many meals per labor hour as in a conventional kitchen.
At present, food is often shipped cold and then rethermed at satellite sites in a convection oven. But this method cooks the food too fast, and then overcooks it. As with any other oven or furnace, a convection oven set at 300°F actually fires at 550°F until it reaches 300°F. That’s not good for retherming.
Good retherm cabinets, the equipment of choice, are much like prime rib slow-cook ovens. They’re a much gentler heat source. Hot items can be transported in mobile warming cabinets, which are then plugged in at the satellite, where they warm the food to about 160°F.
CEL: Does a shift from thaw-and-serve, to cooking from whole ingredients, mean that school districts must buy industrial-sized equipment?
SM: I recommend going large with some equipment such as high-volume cheese cutters. Government commodity cheese comes in giant blocks. You wouldn’t normally have equipment to cut those blocks in an elementary school kitchen. And then you need equipment to grate it, if you’re making your own tacos, burritos, and pizza. A high-speed automatic grater accomplishes in one hour what it would take a human 10 hours to accomplish with a hand grater. It’s the same thing for pressing cookies versus using a cookie dropper. Of course, cheese can be purchased grated or cookies already formed and frozen, but food costs will be higher and this leads back to processed foods.
"Preparing fresh food from fresh ingredients" doesn’t mean that the cafeteria is a restaurant serving a hundred meals, and chopping all the lettuce with a knife. It’s not different from chopping radishes or mixing ingredients in your own kitchen in a Cuisinart®. A Cuisinart® is 10 times as fast as hand preparation. Food service just has bigger Cuisinarts. An automatic reversible sheeter is just a high-speed rolling pin. Same principle, more appropriate scale.
CEL: Any other advice for school districts?
SM: Remember that this whole process requires trade-offs. Districts may not be able to serve nutritious, fresh food and expect their food services to make money. Labor and equipment costs may go up, but the hoped-for trade-off is being able to use seasonal local ingredients, which are often higher in nutrition, less expensive, with much lower transportation costs, and less expenditure on packaging that will end up as solid waste. Creating infrastructure appropriate to the district’s desires and resources is a challenge, but in the end it is possible to offer quality food to our children, at less cost than many people assume.