Visual tour of a LEED Gold office building
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When Bick Group set out to build our new headquarters in St. Louis in June 2006, we challenged our staff to convert a former printing company’s building into a state-of-the-art showcase for occupant comfort, IAQ, energy efficiency, and water conservation.
The team succeeded. The building was certified as LEED Gold by earning 44 points under the U.S. Green Building Council’s LEED for New Construction version 2.1 rating system.
Although the building belongs to Bick Group, we treated the project from start to finish as if it were for an outside client. This helped provide cost and schedule controls that would reflect real-world costs and benefits. Size-wise, the building is 49,183 sq ft, of which office and support require 28,863 sq ft. Support areas include a small data center, a print shop, and an employee cafeteria. The adjacent warehouse is 20,320 sq ft. The cost for the project amounted to $110 per sq ft, and energy savings have reduced operating expenses by 25% based on the first year of occupancy.
The new facility isn’t just a showcase for our customers; we regularly host public tours of the facility, providing the region with a living example of green principles for a sustainable built environment. This article provides a visual tour of much of the facility, pointing out many of the green features to an audience wider than Bick Group can accommodate through actual visits.
Site, shell, and infrastructure
Acting as its own design-build contractor for the project, Bick Group renovated the 49,000-sq-ft, 40-year-old John Stark Printing Co. building, combining a flexible infrastructure with intelligent, well-integrated building controls and management systems. In the process, we were able to reuse 75% of the original shell structure while taking advantage of the building’s size and interior configuration, its accessibility, and its southerly alignment on the property (Figure 1).
Because so much shell reconstruction was planned, Bick took the opportunity to improve the thermal performance of the shell and reduce heating and cooling loads. This permitted downsizing the HVAC equipment for first-cost savings in addition to operational savings.
To reduce heat conduction through the skin of the building, the insides of the exterior walls were furred out and soy-based insulation was sprayed in. The insulation has an R-value of 3.83 per in., for a total wall system R-value of R-22. This type of insulation provides more complete coverage and seeps into all the nooks and crannies, serving as a vapor barrier as well. And, because the insulation is soy-based, it is made from rapidly renewable materials that contain no VOCs. A key component in the building’s flexible infrastructure is a raised access floor system, combined with an underfloor service distribution system. This design distributes modular, plug-and-play power, voice, and data cabling as well as HVAC delivery below the floor plate. Reusable cabling under the floor is color-coded and connected to modular junction units, reducing
waste, reconfiguration time, and the costs associated with churn. On-site facility managers can access and move wiring and cabling services simply by removing the panel that contains the power-voice-data (PVD) termination boxes and switching it to an alternate location (Figure 2).
One of the most important aspects of the new headquarters is its networked facility management system (FMS), which integrates and controls multiple building systems. For example, the FMS automatically regulates energy use based on daylight, weather changes, and occupancy population and activity. Energy savings from lighting is especially dramatic, with average lighting power consumption at approximately 0.34 W/sq ft instead of a typical building’s 1.0 to 1.5 W/sq ft. Lighting power reductions also reduce cooling loads for additional energy savings.
Bick engineers programmed the sequences of operation using algorithms they have engineered for customers. They also
created a dashboard that displays energy use, status of IAQ parameters, and whether it’s optimal to open windows (Figure 3).
Indoor environmental quality
Bick took a holistic approach to indoor environmental quality (IEQ), even going beyond LEED to include acoustic measures. The building’s interior design, furnishings, and systems provide comfort, healthy IAQ, a visual connection to the outdoors, and sound attenuation.
An underfloor air distribution system uses constant volume diffusers and underfloor VAVs that can be reconfigured easily and relocated as spatial layout changes, further reducing the costs associated with churn. The system also takes advantage of air’s natural tendency to rise as it warms. Air distributed from beneath the floor is introduced at a lower velocity and higher temperature than overhead systems. As a result, it requires less fan horsepower to deliver the air and provides the opportunity for extended economizer operation, thereby reducing
energy consumption and operating costs. Another benefit of supply air introduced into the space this way is that it improves IAQ, as natural convection moves warmer, stagnant air out of the occupied zone and toward the ceiling returns. In-floor diffusers allow staff to adjust volume and air direction control at each workstation.
A 55-ton rooftop unit is the primary source for cooling and incorporates a hot water reheat coil for morning warm-up. This standard unit was fitted with a bypass duct with control damper to allow for summer dehumidification without needing energy for reheating. During moderate outside air temperature, the unit has 100% economizer capacity allowing for free cooling with high-efficiency filtration.
Linear diffusers along the building perimeter provide added heating and cooling for skin losses during cold winter and hot summer periods (Figure 4).
During winter months, a hot water loop supplied by a high-efficiency, gas-fired, full-modulating boiler
provides additional heat along the perimeter. The fan is energized to recirculate room air to the perimeter, and then the heating coil is opened to provide supplemental heating, meeting ASHRAE 90.1 2001 guidelines.
The FMS allows employees to open every other bank of lower windows. Based on outside weather conditions and outside air quality, the FMS will generate and send an e-mail to employees whose workstations are along the building’s perimeter, informing them they can open their windows. If weather conditions change or as the workday draws to a close, the FMS will generate another e-mail to employees, reminding them to close the windows in their areas. At the end of the day, the windows are inspected visually to ensure that all have been shut (Figure 6).
little or no VOCs, contaminant levels inside the building and the amount of fresh air that enters the building are monitored carefully. Two IAQ sensors, one on the west side and one on the east side of the building, use aspirators to continually draw in air and analyze its quality. These sensors detect concentration levels of carbon dioxide and some 30 VOCs including formaldehyde, ammonia, chlorides, and benzene. Based on concentration levels, the HVAC system automatically regulates the amount of fresh air introduced into the building.
Bick Group also addressed the acoustical concerns often associated with an open floor plan by deploying an underfloor sound-masking system. The system uses 86 sound masking speakers distributed evenly under the floor, eliminating typical overhead system installation components such as shoots, pins, hanger assemblies, and wire drops. By placing the system under the floor, engineers achieved a cost savings of 10% to
15% versus a similar ceiling plenum system.
Daylighting and lighting controls
To increase the amount of daylight in the building, Bick Group replaced the windowless south wall with a curtain wall that features highly insulated low-e glass with a clear coating that reduces solar heat gain.
All east and west windows have shades that raise and lower automatically, depending on the angle of the sun as determined by the time of year, time of day, and the amount of outside light intensity measured by photo sensors located on the exterior walls. Employees can override the automatic settings from their workstation using a Web browser.
These sunshades prevent direct sunbeam penetration and minimize glare. The sides facing outward have a silver reflective coating to further reduce solar gain, while sides facing inward are black. However, tiny holes that comprise 5% of the PVC-free shade fabric allow some beneficial daylight into the space.
The combined effect is similar to a polarizing lens, allowing occupants to see through the dark fabric to the outside. Over the shades are interior light shelves. The tops of the light shelves protect the interior from direct sunlight and bounce daylight to the white, reflective ceiling, projecing natural light deeper into the occupied space (Figure 7).
The most dramatic of the daylighting features, however, are the three rooftop
All conference rooms and private offices have occupancy sensors. In the general areas, the
lighting is interfaced with a card access system; when someone enters the building during unoccupied times, the lighting in their work area will turn on and then be controlled based on available daylight.
Water efficiency also is addressed. In the building’s cafe, for example, all kitchen sinks are equipped with low-flow heads to reduce water usage (Figure 9). In addition, occupants are encouraged to take advantage of the cafe’s filtered water system instead of purchasing bottled water to mitigate the
environmental impact of its manufacturing and distribution process.
All restrooms include low-flow, motion-sensor faucets, and restroom hot water is provided by local, on-demand (tankless) high-efficiency water heaters, which use less energy than traditional storage water heaters. Finally, no-water urinals save an average of 40,000 gal of potable water per year, and water closets feature dual-flush valves to provide additional water conservation.
Measured energy savings
The energy performance of the building has exceeded expectations. The building modeling results estimated electric use at 363,773 kWh and gas at 7,971 therms (see Table 1). However, the building outperformed the modeling estimates by 24% for electric and 46% for natural gas. Overall, the integration of the building shell, daylighting, HVAC system, and other green features provides a 25% annual savings in building operating costs for Bick Group.
Design and construction costs for the new Bick headquarters totaled approximately $5 million, or $110 per sq ft. Owners anticipate that energy and efficiency savings will quickly pay back the investments they made in sustainability. In the meantime, the 85 employees who work in the newly renovated Bick Group headquarters are enjoying an environment that maximizes their efficiency and intelligently manages the resources around them.
Table 1: Energy modeling results versus first year of occupancy (June 2006—June 2007). Subsequent energy performance has been comparable.
|Electricity consumption (kWh)||Electricity Cost ($)||Gas consumption (therms)||Gas cost ($)||Total energy cost ($)|
|Source: Bick Group|
|Building model estimate||364,773||$24,237||7,971||$8,250||$32,487|
|Actual first year usage||276,326||$18,787||4,308||$4,584||$23,371|
|Tinucci is a senior vice president at Bick Group with more than 35 years of experience in the building controls industry. He is a member of the Building Owners and Managers Assn., ASHRAE, and the U.S. Green Building Council.|