Up or Out

• By John Hill
• 10/01/15

Available land is becoming scarce in many communities and the cost of land and quality school buildings continue to rise. Demand for ballfields is at an all-time high, communities have a growing awareness of the value of green space, and school systems are more aware than ever of energy efficiency and long-term building maintenance costs.

It is no surprise, then, that communities are looking more closely at whether to build up or out — whether to build multistory schools or single-story schools. Many arguments are put forward as to why multi-story schools might have cost and environmental advantages, but where is the data? In an effort to contribute data-based information to this discussion, Grimm +Parker Architects undertook a study to compare construction costs, life cycle costs, environmental impact and other factors important to communities struggling with this choice.

We established a model grounded in reality: a real site —Stafford County, Va: a prototypical elementary school easily adapted to both single-story and multi-story options; and operation and maintenance numbers from similar schools in the local district. The numbers produced are in many ways specific to this site and building, but we believe they are typical enough that data trends can be extrapolated to similar facilities.

Our model school was designed to accommodate 600 students in grades PreK-5, with 66,550 square feet of net usable area. The gross square footage of the single-story option was 89,511 and for the two-story option, 91,431, owing to required stairwells and elevator.

The Results?

Land area for building footprint:
67 percent greater for the one-story model

Impervious Area:
30,660 square feet more for the one-story model, producing over 19,000 gallons more storm water run-off than the two-story model

Cost of Construction:
The two-story model had higher costs for stairs, elevator, and structural framing; but those costs were more than offset by the single-story’s higher costs for exterior envelope (roof and wall), utility excavation and SWM, grading and foundations.

Professional cost estimators calculated the one-story model to be close to $1 million more than the two-story option. This estimate did not include land costs, but included a “land premium” for the additional land needed for the one-story model, based on land costs in the region, which added $66,500.

Life Cycle Cost:
Over the 30-year life cycle, the two-story option’s initial cost savings of almost $1 million grew to over $2.1 million. Note that Stafford County is fortunate to have low energy costs, averaging between $1.10 and $1.20 per square foot of building area, so these numbers will vary depending on regional energy costs. Higher energy costs will lead to greater life cycle cost savings in the multi-story model.

Some factors that must be considered were difficult to quantify, like:

• the cost of maintaining storm water management structures;
• the greater availability of usable sites and flexibility for building orientation when a smaller footprint is used;
• the value of using less land for the building, thereby having more green space or ball fields and reduced water runoff into neighboring streams; and
• shorter travel times in the two-story option, which might increase time for learning yet introduce obstacles to those with mobility impairments.

On balance, there are many cost, operational, and environmental benefits to multi-story schools. Although we looked at a specific elementary school example, it is reasonable to speculate that middle and high schools would reap the same benefits on a larger scale. It is important to note that the study confirms our real-world experience based on schools of 60,000 square foot or more, but it is also our experience that smaller buildings of less than 60,000 square foot may see reduced or even no cost benefits with a multi-story option.

Differing community values and different specific conditions make it unreasonable to state that multi-story solutions are always the best solution. However, the cost data and environmental benefits advocate strongly for communities and school districts to consider multi-story solutions for their new school buildings.

The full study and data results are available at www.grimmandparker.com

This article originally appeared in the issue of .