Designing efficient office buildings with visual appeal: Codes and standards
- Jason Gerke, Mechanical & Plumbing Group Manager, GRAEF, Milwaukee
- James Hansen, PE, BEMP, LEED AP, Principal and Senior Mechanical Engineer, GHT Ltd., Arlington, Va.
- Tyler Jensen, PE, LEED AP, Senior Associate, Environmental Systems Design, Inc. Chicago
- John Yoon, PE, LEED AP, Lead Electrical Engineer, McGuire Engineers Inc., Chicago.
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 office building projects?
Gerke: As a mechanical engineer, ASHRAE standards are always on my mind as a benchmark of good design. While codes may not require the use of ASHRAE standards, it is this engineer’s opinion that those standards should be looked at the industry standard of care. What better set of standards to point to if there is ever an issue with a building you designed? Most of these standards are focused on occupied buildings, which include office spaces. Besides ASHRAE, we typically see International Code Council (ICC) sections ranging from the International Building Code and International Mechanical Code to the IECC. There are many other ICC codes that are adopted in many jurisdictions throughout the United States.
CSE: What are some best practices to ensure that such buildings meet and exceed codes and standards?
Gerke: ASHRAE offers advanced energy design guides for a number of building types that can be downloaded for free. These are excellent technical resources that provide guidance on methods to reduce energy use. Consider using carbon dioxide sensors, vacancy sensors, and other occupant-sensing technology to reduce energy use in unoccupied spaces. Also, consider methods that may be used to verify airflow volume, temperature, and humidity at the system level and in building spaces. Verifying these parameters will ensure that code requirements are being met and only the necessary setpoints of the system flow or temperature are met, instead of overshooting in these areas due to a lack of sensors with output to an HVAC control system.
CSE: How are codes, standards, or guidelines for energy efficiency impacting the design of such buildings?
Jensen: Energy code prescriptive requirements for building envelopes are becoming increasingly stringent. Office building owners and architects want highly glazed facades, but it is now very difficult to comply with energy codes using the trade-off method for envelope compliance. This means that the mechanical systems must be designed to offset the envelope, and office buildings must use the energy-cost budget method to demonstrate code compliance, performing a whole-building dynamic energy model.
Gerke: One of the ways that codes, standards, and guidelines are affecting how we design buildings is the requirement for verification of conditions through building control systems. This could be the requirement in some jurisdictions for reporting energy use, verification of airflow or space temperatures to meet standards, or other control system design guidelines. Using automation systems in buildings will continue to increase to facilitate immediate control and access to trend data to prove system performance.