Designing efficient K-12 schools: Codes and standards
Maxwell Chien, PE, LEED AP BD+C, Associate, Kohler Ronan, New York City
Chuck Dale-Derks, PE, LEED AP, Principal, McClure Engineering, St. Louis
Evan J. Hammersmith, PE, LEED AP BD+C, CGD, Associate, Mechanical, Karpinski Engineering, Cleveland
Michael Lentz, PE, CPD, HFDP, Director of Operations, Baltimore Office, Setty, Baltimore
Rodney Oathout, PE, LEED AP, CEM, Principal | Energy + Engineering Leader, DLR Group, Overland Park, Kan.
Michael Rader, PE, CEM, Vice President and Chief Operating Officer, Barton Associates Inc., York, Pa.
CSE: Please explain some of the codes, standards, and guidelines you commonly use during the design process. Which codes/standards should engineers be most aware of in their design of engineered systems in K-12 schools?
Chien: Local state codes are followed, along with ASHRAE standards. Engineers should be most aware of NFPA standards, as many schools include auditorium stages that require smoke control—and high-rise schools require stair pressurization.
Dale-Dirks: Our industry has made a mess of the codes with frequent and significant changes. Voice-evacuation fire alarm systems are required for all education occupancies. This may add about $3/sq ft to the facility cost and takes a great deal of effort to truly be intelligible.
Carbon monoxide detection in classrooms per International Building Code (IBC), Section 915, is new and located in the building code, but it belongs in the mechanical or electrical code. Combination smoke alarm/carbon monoxide alarms may provide the best notification and system simplicity; however, functionally, carbon monoxide detectors should be located in the breathing zone (about 4 to 5 ft. above the floor), whereas smoke detection must be within a foot of the ceiling to detect smoke or heat in an acceptable response time. Carbon monoxide is not directly related to fire protection in buildings.
CSE: How are codes, standards, or guidelines for energy efficiency impacting the design of such buildings?
Hammersmith: The new ASHRAE 90.1: Energy Standard for Buildings Except Low-Rise Residential Buildings and ASHRAE 62.1: Ventilation for Acceptable Indoor Air Quality standards and their adoption in building codes are continually driving construction toward greater efficiency. In low-occupancy buildings like houses, the insulating value of the envelope (walls, roof, and windows) drives energy consumption. In high-occupancy buildings like schools, though, the conditioning of ventilation air drives energy consumption. The most effective way for schools to save energy is to control the amount of ventilation air provided to spaces during times with minimal or no occupancy. A variety of control techniques allow the BAS to detect occupants and then tailor the amount of air to that space.
Dale-Dirks: Added requirements for energy recovery has made some HVAC equipment difficult or unsafe to maintain. Stacked units with vertical wheels require service heights of 13 to 14 ft for moderate-sized units. There are no easy means of integrating structural service platforms into the unit without interfering with some access or adding significant cost to the project.
CSE: What new code or standard do you feel will benefit K-12 schools? This may be a code that your authority having jurisdiction (AHJ) has not yet adopted, but will directly impact your work in the future.
Oathout: We believe the WELL Building initiative will have a lasting impact on K-12 school design. The research continues to provide evidence on the positive impact of biophilia, thermal comfort, and indoor-air quality on the performance of students. We should not forget that K-12 buildings are the workplace for millions of people who also benefit from buildings designed with wellness in mind.
CSE: How will updated codes and standards (e.g., ASHRAE 90.1) impact decision-making for new and existing K-12 schools?
Rader: I think that it will mandate more of a focus on the mechanical and electrical systems within a building. It will emphasize making decisions with a long-term focus.
Oathout: The continual evolution of ASHRAE 90.1 always has a significant impact on how a building is designed. The design requirements also have an impact on the occupants. Classroom lighting is one example of a unique design opportunity for the engineer. The desire of varying light levels by the instructional staff combined with lighting control requirements of ASHRAE 90.1 can result in a very complicated lighting control system if not designed carefully.
CSE: Give an example of a project that conflicted with what the building owner wanted and certain codes and standards. How was this situation resolved?
Dale-Dirks: We had a project where the Department of Health could not agree with the plumbing inspector. We provided a direct connection to please the plumbing inspector, then cut the connection, installed a funnel, and passed inspection for the indirect connection requested by the health inspector.
Chien: The Americans with Disabilities Act (ADA) standards are a big factor in designing schools for accessibility. One issue we encountered was when the owner wanted longer door-opening time than required for wheelchair accessibility. This also affected the vestibule’s ability to hold heat, as the air change in that space increased significantly. Eventually, the owner decreased the door-opening time to ADA requirements and staggered the vestibule doors.
CSE: What is the communication process like (or how should it be) between decision-makers to ensure that the building design is code-compliant?
Chien: The AHJ review process has proved beneficial in many cases to make sure that the design intent also meets local jurisdictions’ codes and standards. Throughout the process of design, we have one-on-one meetings with the AHJ to go over specifications and drawings, which proves to be beneficial to capture missing requirements prior to bidding.
Dale-Dirks: It is absolutely necessary to have preliminary design discussions with the AHJ. Presenting your project so the AHJ has input, understands the needs of the project, and has an early agreement on the approach ensures a smooth construction project. This can be especially true for partial occupancy in an early phase while waiting on completion of the balance of the project to get the building up to date with the latest codes and safety features.