An overview: Designing office space
Michael F. Cooper, PE, LEED AP, Managing Principal, Harley Ellis Devereaux, Southfield, Mich.
Kurt Karnatz, PE, CEM, LEED AP, HBDP, HFDP, President, Environmental Systems Design Inc., Chicago
Kent W. Peterson, PE, FASHRAE, LEED AP BD+C, BEAP, Vice President/Chief Engineer, P2S Engineering Inc., Long Beach, Calif.
CSE: What sorts of challenges do office buildings pose that you don’t encounter on other projects?
Michael Cooper: Adaptability is one of the biggest challenges we see in this sector right now. Office buildings house diverse tenant populations and functions including professional, medical, studio, food service, and big data. Building systems must be highly efficient and also adaptable for varying and changing tenant requirements. Another is return on investment. Recent economic challenges have driven more aggressive construction budgets and schedules to help owners/developers reduce their total cost of ownership. Adequate planning time for these projects is essential for a lean design and construction process.
Kurt Karnatz: In office buildings, the building envelope and the architectural look or aesthetic tends to be more emphasized than in other types of buildings. We design buildings all over the world, and one of the challenges we face is that very often, site-specific opportunities are overlooked or addressed in less than optimal ways. Too many office buildings built in the past have little sense of place in terms of building envelope and systems, and as a result it is often hard to tell what city you are in when looking at a building in terms of look and mechanical, electrical, and plumbing (MEP) systems. We are encouraged by the embracement of regional design, which has led to innovation of sustainable systems application and integration. We find that truly optimized engineered systems for office buildings can be accomplished at a much greater degree when building envelope and siting is specific to the region where the building is being built.
Kent Peterson: Office buildings are considered the most complex and competitive segments in real-estate development. They can range from low-rise to high-rise and from single-tenant to multi-tenant. The major challenges include designing systems to operate efficiently while accounting for large load and occupancy variations.
CSE: How have the needs and characteristics of office buildings changed in recent years?
Peterson: Class A office buildings are being designed to be high-performance green buildings. There is a trend to measure actual energy, water, and indoor environmental quality (IEQ) performance in office buildings.
Cooper: Diverse functions and varying tenant requirements have driven more flexible and multi-use environments. Beyond that, the types of environments that attract the best people and inspire innovation are changing. More collaborative, open spaces allow people to work in the most appropriate setting for the task at hand. As we have looked to shave operating costs, the approach to energy has changed. High-performance building design is not only a tool to reduce operating costs, but a valuable marketing tool for owners to attract new tenants to their building.
Karnatz: Office buildings today must support a greater diversity than they ever had in the past. They must be able to provide for multiple occupancy needs in a flexible and efficient way. Many large office buildings that we work in are constantly being modified because of the changes in tenancy and the specific requirements of the tenancy. Many office buildings today are really mixed-use, which creates both challenge and opportunity for building system optimization.
CSE: What do you need to take into account when engineering systems into office buildings?
Karnatz: Regional/site opportunities, flexibility, efficiency, churn, safety, and comfort.
Peterson: The intended uses of the office building should be well established before design development since this impacts system selection.
Cooper: The first step is the realization that office buildings are more than places where work gets done. They are key assets of the business and drivers of business success. The systems must first and foremost help create a safe, productive, and satisfying work environment. This drives today’s productivity, and also helps attract the next generation workforce. The systems must also help control costs. Proper attention to energy performance and maintainability helps promote system reliability and more predictable operational costs.
CSE: How often are you called on to retro-commission (RCx) an office building?
Peterson: We are requested to RCx buildings roughly five times more than being asked to design new buildings. The primary difference is that the RCx team must understand how the building system should work to perform their functions efficiently for the way the building is actually being used. We usually will get a minimum of one month of critical trend points while interviewing building operators to determine available opportunities for modifying sequences to improve building performance.
Karnatz: RCx is a tremendous opportunity for building owners to derive deeper efficiencies and optimization of existing systems through even just simple recalibration. Our business in this area as well as continuous commissioning has grown considerably compared to new building commissioning (Cx).
Cooper: Not surprisingly, RCx is becoming more prevalent in industry. There are a number of high-quality buildings out there, with “good bones” but with systems that are either near the end of their service life or are inefficient as compared with current technology. RCx helps revitalize these buildings with healthier work environments, more efficient and reliable systems, and lower operating costs. It is often a more difficult process than new construction commissioning in that new systems, in theory, have predictable operating parameters.
CSE: Please describe a recent project you’ve worked on—share problems you’ve encountered, how you’ve solved them, and aspects of the project you’re especially proud of.
Karnatz: An interesting challenge that we have recently encountered on Kingdom Tower, a project in Saudi Arabia, scheduled to be the world’s tallest building, is the difference in the design criteria used in load calculations. The base of the building and the top of the building are actually two distinct climate zones.
Cooper: We have had a number of successful projects, but one area where we often see need for greater attention is integration of owner-provided equipment. This may include information technology, food service, or modular office furniture. Any time an element is “pulled out” of the design and construction process, more communication and coordination are required. Our experience tells us that when we are able to engage with the owner’s suppliers, understand exactly what is being provided and how it interfaces with the overall space, we can effectively incorporate these elements into the building with the desired results.
Peterson: We recently designed two office buildings for a large aerospace manufacturer that have now been constructed and commissioned. The owner requested under-floor air distribution (UFAD) due to the anticipated churn in the office space. We were able to design this system with supply mains below the floors as air highways to serve the large floor templates. This accomplished even distribution across the raised floor.
CSE: Has the economy affected the volume or nature of your office building work?
Cooper: The economy has certainly impacted the volume and nature of our work. Owners have fewer resources available, so opportunities to look at new ways of delivering projects faster and at a lower cost are present. More collaboration between architects, engineers, and contractors has driven higher levels of efficiency into the process. We also find ourselves involved in earlier phases of potential projects, assisting clients in identifying nontraditional sources of project funding.
Peterson: There has been a definite downturn in new construction in the state of California. This has resulted in more building owners evaluating ways to improve building operation and reduce operating costs by more energy efficient operation.
Karnatz: We saw a decrease in new office building construction in 2010 and 2011 around the globe with the market turning upward and the demand for new office buildings increasing in 2012. One interesting result of the economy has been the mergers, acquisitions, and consolidation occurring with many of the companies we work with, which drives reorganization of office needs, and ultimately, new construction and renovation.