Engineering flexible office buildings
Office buildings need to have the ability to accommodate myriad types of businesses and activities to meet the needs of tenants. Here, engineers with experience on such buildings share their knowledge, lessons learned over the years, and emerging trends.
Respondents Cory J. Abramowicz, PE, HBDP, LEED AP, Associate, ESD (Environmental Systems Design), Chicago.
Matt Chandler, PE, LEED AP BD+C, BEAP, Senior Engineer, KJWW Engineering Consultants, St. Louis.
Andrew B. Horning, MS, LEED AP BD+C, Associate & Project Manager, Bala Consulting Engineers Inc., King of Prussia, Pa.
Julianne Laue, PE, LEED AP, BEAP, BEMP, Senior Energy Engineer, Mortenson Construction, Minneapolis.
Matthew Pastore, CxA, Director of Design-Build Services, GHT Ltd., Arlington, Va.
John Yoon, PE, LEED AP, Lead Electrical Engineer, McGuire Engineers Inc., Chicago.
Mike Walters, PE, LEED AP, Campus Energy Market Leader, MEP Associates LLC, St. Paul, Minn.
CSE: What's the No. 1 trend you see today in the design of office buildings?
Cory Abramowicz: The biggest trend in the market we've seen lately is increased monitoring and measurement of energy within the building. This includes adding more meters to submeter chilled water, hot water, electricity, domestic hot water, and outside air because building owners want the flexibility to include or not include services in the tenant leases-and use these services to market to potential tenants. Additionally, tenants want more amenities, such as access to fitness centers, additional conference spaces, and a diverse mix of retail shops and/or restaurants located within the building. They're also increasingly interested in knowing not only how much cooling, heating, and electricity they're using, but also how these services are being distributed. Companies are seeking more sustainable methods to fulfill sustainability initiatives, which is where high-end and flexible controls, technology, and modern systems play a big part.
Matt Chandler: There is increasing awareness of integrating building design with occupant well-being. For example, locating the stairs to be equally convenient and accessible as the elevators promotes stairs use. Another example is moving the majority of the built spaces to the interior of the building and including clerestories so more occupants have access to natural daylighting.
Andrew B. Horning: I've noticed increased flexibility for collaboration.
Julianne Laue: Our clients are asking for building designs that help attract and retain quality team members. They are looking for buildings that inspire health and wellness, are full of natural light, and are flexible and adaptable for future needs.
Mike Walters: A considered move to low-entropy/near-room temperature heating (~120°F) and cooling (~60° F) systems. This is often in the context of district energy or campus-type settings to drive the lowest possible energy use. From a system perspective, this is often reflected as chilled-beam systems, variable refrigerant flow (VRF) applications, or even standard variable air volume (VAV) systems with larger air handling unit (AHU) coils.
John Yoon: In multitenant office buildings, we're seeing more emphasis on providing in-house amenities (shared conferencing facilities, fitness centers, Wi-Fi lounges, "party decks," pop-up restaurants, etc.). What's unusual about this is we're seeing building owners providing these amenities for buildings located in central business districts of large metropolitan areas. You would expect that the inherent advantages of being in these types of locations-being in the middle of everything-would make these types of amenities redundant. However, there is a pervasive fear among building owners that if such amenities aren't provided, they'll be left behind in the competition for new tenants or even in retaining existing ones. It's unclear if this trend is sustainable. Constructing, and more important, operating and maintaining these facilities does severely impact a building's financial bottom line. It may ultimately be nothing more than a passing trend, like the outlandish employee fringe benefits that characterized tech companies in the dot-com era. Only time will tell.
CSE: What other trends should engineers be aware of for such facilities in the near future (1 to 3 years)?
Laue: Engineers should be ready to be "optioneers,"and provide a range of options that look at comfort, reliability, controllability, energy efficiency, first cost, and code compliance. These options will need to be laid out so the owners fully understand the overall impacts they can expect.
Yoon: With the growth of the distributed-generation market, decreasing overall demand, and stagnant electricity rates, we expect to see major efforts by utility companies in pushing for massive overhauls of electricity-rate structures. In this current deregulated environment, most traditional utility companies seem to be struggling with finding new revenue streams so that they can meet the expectations of their shareholders. In an odd twist, many states are forcing their regulated utility companies to enact consumer energy efficiency programs, which if successful, can only further reduce revenue for the utilities. The "answer" that many regulated utility companies are embracing is shifting from usage kilowatt-hour-based rates to demand kilowatt-based rates. The primary argument by utilities is that demand-based rates more accurately reflect the true cost of delivering electricity. With the deployment of smart meters, such rates changes are now more technically feasible. The only hurdle is legislative, and there is a significant lobbying effort in many statehouses to make this happen. So why does a change in electrical utility-rate structures matter? The two greatest costs for most office building owners are taxes and utilities. The prevailing expectation is that demand-based rates will significantly increase utility costs for most buildings. Taking this into consideration, simple energy efficiency considerations in base building mechanical, electrical, and plumbing (MEP) system design isn't enough if rate structures do change. MEP design will eventually also have to address maximum concurrent demand, "capacity factor," and other seemingly foreign concepts.
Horning: Engineers should be aware of a less-built environment with accessibility to informal meeting spaces-i.e., bench-style workstations with huddle/scrum/war rooms for four to 10 people and modular furniture and wiring kits of parts to address office-space churn.
Chandler: Many of the current and future trends include evolving technologies, such as electronic room-scheduling displays outside of shared conference spaces. These room schedulers integrate with the scheduling software used by the occupants and display real-time information on stationary and portable electronic devices, eliminating the need for daily updates of posted paper schedules. New wireless audio/video (AV) technologies also are becoming more prevalent, potentially reducing the need for fixed inputs in the floors or walls. In addition, video/media walls and digital displays are growing trends. Open offices with shared conference space promote a collaborative environment, and we are seeing an increased use of furniture solutions and demountable partitions in lieu of fixed construction as well as interior offices and clerestory windows to promote access to daylight.