Building Name: DPR Construction Phoenix Regional Office
Bulding Location: Phoenix, Arizona, United States
Project Size: 16533 ft sq
Building Type: Office
Project Type: Existing Building Renovation or Retrofit
Delivery Method: Integrated Project Delivery
Total Building Costs: $150/sf
Project Completion Date/Building Occupied: October 7, 2011
Energy Systems Design
Green Building Consultant:
San Diego, California
Authority Having Jurisdiction: City of Phoenix
Since the completion of Aspect Communications World Headquarters in San Jose, CA, in 2001, DPR Construction, a national general contractor/construction manager, has been dedicated to being a world leader in sustainable construction. In 2006, they joined the EPA Climate Leaders and made a commitment to reducing company-wide GHG emissions by 25% per employee by 2015. In 2010, they built the first building in San Diego to be Net-Zero Energy and LEED Platinum.
Continuing this dedication, DPR Construction, when deciding to "build" a new Phoenix Regional Office, wanted to integrate their values and culture by creating a model for how to live and work in the desert, while providing a great employee environment, sustainably and cost effectively. The result, a 16,355 square foot office building, transformed an abandoned, distressed building in a redeveloping community of Phoenix into a modern sustainable facility. In doing so, they not only refurbished an old building but they broke down the perception barriers to Net-Zero Energy, transformed the conversation about environmental stewardship and 'doing what's right', and inspired an entire community to follow suit.
DPR Construction's Phoenix Regional Office is a prime example of urban revitalization and integrated sustainability, and speaks volumes to the successes that can be achieved when the entire team is integrated around owner driven goals. Acting as owner and contractor, DPR hand-selected the project team based on their sustainability expertise and track-record of collaboration; this included the architect, energy consultant, and numerous specialty subcontractors.
A majority of the team was engaged prior to purchase in order to evaluate the potential of different project sites. While many sites were evaluated, a single-story 40-year old, distressed adult-themed (retail) boutique, a visual reminder of the urban blight Phoenix struggled to revitalize, was ultimately chosen. Located on a highly visible and busy intersection, surrounded by previously developed land with mid-rise commercial buildings, the project is ideally situated within a mile radius of numerous restaurants and a light rail stop connecting the project to Mesa, Tempe, Downtown, and West Phoenix. The project's proximity to Sky Harbor allows visiting colleagues to take Light Rail directly from the airport, reducing emissions commonly associated with travel.
From the outset, DPR established the goals of meeting Net-Zero Energy and that all strategies meeting a 10 year return target would be included. They challenged the team to think innovatively and insisted that no idea was a bad idea. They made it clear that all approaches including those strategies that would impact building occupants, like raising acceptable comfort conditions, were valid and would be considered.
DPR's existing lease was up at the end of October 2011 and when the final site was selected in December 2010, it left only 10 months for design, permitting, and construction. The project evolved quickly and required weekly team meetings to vet all concepts and approaches proposed by the project team. Each proposal was evaluated thoroughly and when appropriate, modeled to determine the overall impact on the projects goals. With building orientation predetermined by the existing structure, the design approach was to create an adaptive response to the environment.
South and west facades are left largely intact with little to no openings helping to buffer the space from the harsh desert sun. Both the east and north facades are punctuated with large expanses of high performance glass to allow in natural light. Horizontal shading devices are used to minimize direct solar gain and daylight analysis revealed that translucent shades allowed for more even daylighting. When combined with the natural light provided by the 82 solar tubes located throughout the building, they provide enough light during operating hours to reduce artificial light usage by over 70%.
The large glass areas connect occupants to the exterior courtyard where vertical steel screens, draped in vines, help to filtering light, air and dust, screen views of adjacent parking and bring nature into view. These features create 2,600 square feet of outdoor wellness space and extend the areas yearly use. The buildings perimeter walls were adequately insulated but the roof required additional insulation along with a new reflective coating. The decision by the owner to renovate versus building new was a prime example of trying to reduce material impacts. 93.7% of the existing structure remained in the final design.
The owner also wanted their existing built-in workstations to be accommodated in the new space. In the end, only three additional workstations were built for the new space. Materials were chosen because of their environmental attributes and combined to create a vibrant, modern environment free from many hazardous pollutants. 97% of the wood used on the project came from FSC sources. Screen walls located throughout the office are made from FSC bamboo, a rapidly renewable product that accounted for 3.35% of the material value on the project. All finishes were specified with low or no-VOC content. Over 32% of material value on the project was recycled content and over 12% was regionally extracted and manufactured. The project also diverted 78% of all materials removed from the site to be recycled and reutilized which reduced landfill waste by 252 tons.
Natural ventilation was explored extensively and is characterized by the four black, corrugated, passive 'shower towers' on the eastern facade and an 80' long, 13' high, zinc clad solar chimney on the roof. Early CFD modeling determined that natural ventilation strategies were feasible but in order to achieve maximum air flow up and through the custom solar chimney, increased airflow from the towers would be required. This was resolved by adding showerheads and misters in the towers to help increase pressure and draw air more quickly through the towers and into the space. A weather station on the roof reads climatic conditions and adjusts these systems accordingly. It has the ability to open windows, activate the passive evaporative cooling towers, and control heat through the solar chimney. These systems combine to generate16 tons of naturally cooling, enough for the open office space and further reduces mechanical cooling/heating needs by 24% of annual operating hours.
Part of a Bioclimatic response must come from the occupants. Living in the desert is an exercise in compromise and the owner and employees elected to adjust their 'comfort' conditions to account for higher temperatures. One way of doing this was to install Big Ass Fans which allow for expanded temperature set point ranges in the space; moving from a 70 to 78 range to a 68 to 82 range. As part of a holistic approach, DPR spent a great deal of time educating their staff about these adjustments, getting buy-in from the group and giving them the flexibility to adapt to these new conditions. Plug load reduction was also a heavy focus for DPR. After design and operation of their Net-Zero facility in San Diego, they realized the importance of plug load reduction strategies. They evaluated every piece of equipment for energy efficiency and even implemented a 'vampire' switch. The vampire switches are located at the main entrance to the facility and all non-essential loads are tied to it. The last person out the door each day hits the switch, shutting off 90% of the after-hour 'vampire' loads. These strategies resulted in a 38% reduction in plug loads from those predicted (data based on measured performance after 1 year of operation).
Through deeper exploration of the energy model outputs, the team investigated infiltration, daylighting, increases to envelop insulation, and adjustments to the 'peak' design conditions, aligning these with more realistic conditions. This analysis led to right-sizing the equipment, eliminating the typical overdesign of heating and cooling systems by 25% and 15% respectively. In aggregate, each of these adjustments led to a 35% reduction in building loads. All of the existing mechanical units were replaced with high-efficiency units, while a direct digital control system provides precise temperature control and makes smart operational decisions, providing energy and operating cost savings over conventional systems. The mechanical systems are separately metered to allow for continuous feedback and adjustment of the controls and operation of the equipment.
After one year of operation, the HVAC system actually utilized 45% more energy than estimated but was more than offset by other savings. High efficiency compact fluorescent light fixtures and daylight sensors where used throughout the open office space. Occupancy sensors are utilized throughout the balance of the spaces. Overall, daylighting, controls, and occupant motivation helped reduce lighting energy use by 23% from what was predicted in the energy model. LED fixtures are utilized for all exterior lights and DPR has these fixtures turn off after certain hours to minimize energy use during unoccupied hours. All lighting is separately metered to provide for continuous measurement and verification. While water remains a critical resource for much of Arizona, DPR chose to focus on reduction strategies, as many 'reuse' strategies proved to be prohibitive on such limited access to rainwater and greywater.
Inside the facility utilizes highly efficient fixtures which include waterless urinals, dual-flush water closets, 0.5 gpm, 10-second duration, automatic sensor lavatory faucets, and 1.5 gpm shower heads. The kitchen sink even utilizes a 0.5 gpm aerator and all of these features combine to reduce interior water use by 41% over LEED 2009 baselines. For drinking water, the project uses a CL Free water purification system that removes residual chlorine while filtering and saves significant volumes of water compared to more traditional RO treatment system. Drought tolerant landscaping and a drip irrigation system combine to reduce outdoor potable water use by over 75% over LEED 2009 baselines. Condensate is captured from the buildings multiple roof-mounted heat-pumps and used as replacement water for the building's shower towers. Domestic hot water heating is provided via a roof mounted solar thermal system with electric back-up systems for sinks and showers. These features and many others, combine with a 79kW PV array to help the DPR offices achieve Net-Zero Energy.
Project Results / Lessons Learned
The strategies implemented, as described in the section above, demonstrate that the DPR Construction Phoenix Office is a leader in sustainable design. The project demonstrates the value of deep energy retrofits and the positive benefits on urban revitalization. The project has successfully achieved LEED Platinum certification and Net-Zero Energy Building Certification.
All spaces in the building and across the site are readily accessible.
The DPR Construction office is characterized by the raw integration of sustainable strategies and a focus on material simplicity. It has been honed down to its necessary components, each residing exactly where it needs to be to both perform and provide aesthetic value. Much like a desert cactus, it has evolved to its place.
The project budget was $150/sf, and every strategy was evaluated under the 10-year return criteria established by DPR. This gave the team unlimited flexibility to test a wide array of strategies. The existing heat pump system was one item that proved challenging. Replacement of the system with newer, more efficient equipment didn't pencil out within the 10-year timetable. DPR took a non-monetary value approach, considering the life of the equipment and the future impacts required to replace this equipment and displace their employees, and decided that this was the time to upgrade the systems; even if they had a longer payback. Overall DPR projected a 12-year payback on the entire construction project but, after two years of operation and continuous improvements, the payback will be closer to 8 years.
FUNCTIONAL / OPERATIONAL
The project was designed and built to be a 100-year building. Its open office environment lends itself to adaptability among many different uses over time. The project was conceptualized as a living laboratory for how to live and work in the desert. All of the major systems are exposed and highly organized and each circuit is routed back to a specific meter allowing for continuous monitoring and the flexibility to change, alter, upgrade, move, add, or remove components and technologies as they come to market. The BMS system was custom built to be an intuitive interface that is adaptable to these changes over time. A 79kW PV array utilized as covered parking will offer Net-Zero performance for the facility into the future.
The DPR facility includes secure bike parking, employee showers, and a large fitness center, providing easy access to exercise without having to restructure the day. A nap room allows for quiet time or just catching up on a few winks during the day. In keeping with the Workplace of the future theme, there is an array of conference rooms around the open office space, offering a variety of sizes and functionality; from single person phone rooms to a 40 person training room. Each space is separated from the open environment with a frameless canted glass wall that eliminates glare and reflection and extends the natural light deeper into the building. Functional back of house program spaces, like copy center, file storage, server rooms and bathrooms are all pushed to the perimeter zones of the building acting as a buffer from the west and south exposures. There are several large format glass garage doors that open on the north elevation extending the interior spaces outside into the living courtyard space. Wi-Fi is provided outside to encourage users to work outdoors. Wrapped in steel mesh and vines, the outdoor space offers a respite from work and privacy from the parking area and surrounding streets.
PRODUCTIVE / HEALTHY
As described above, the DPR Construction office in Phoenix offers an array of features to enhance productivity and support active lifestyles. The fitness center gives employees full access to a wide array of gym equipment and the flexibility to utilize this equipment at any point during the day. The stresses of a busy schedule can make it difficult to find time to 'run to the gym' and this space eliminates the time and expenses typically associated with gym membership. The nap room is an opportunity to rest or relax during a long day and everyone is encouraged to use it as they feel necessary. The abundant natural light allows occupants to connect their circadian rhythms to the day and minimizes the strain typically associated with artificially lit spaces. The buildings natural ventilation system provides adequate fresh air into the facility when outdoor conditions are appropriate and the buildings HVAC system exceeds the outdoor air ventilation rates required by ASHRAE Standards 62.1-2004 by over 30%; it can be adjusted to 100% outside air when necessary.
While the existing structure is not part of a historical registry, the project is a prime example of an adaptive reuse and a deep energy retrofit. It demonstrates the possibilities that lie within our existing building network in the U.S. and points to the inspiration and community impact these facilities can have. The 1980's building was devoid of windows and left much to imagination. What was done should extend the structure's life for many years to come.
SAFE / SECURE
The building was designed to meet the 2007 International Building Code. The vegetated screen wall around the perimeter courtyard offers a second layer of security to the buildings. These canted screens rise 12' above grade, making climbing difficult.
Information and Tools
Design Software: Array
Energy Simulation Software: Energy Plus, Trane Trace
Benchmarking Software/Methodology: CBECS, Energy Star Portfolio Manager
Other Tools: CFD Modeling
Energy was by far the most scrutinized aspect of the project. Each strategy was evaluated based on its cost and net contribution to the Net-Zero goals. The entire team was guided by DPR's commitment to any strategy that had a payback of 10 years or less. See narrative in the Evaluation section for individual energy related measures.
Annual Energy Use by Fuel
Electricity: 129,624 kWh
Fuel Oil: 0
Other fuel: 0
Total: 129,624 kWh
Annual Energy by End Use
Heating: 14,395 kWh
Cooling: 50,893 kWh
Fans & Pumps: included above
Lighting: 20,155 kWh
Domestic Hot Water: 5,670 kWh
Plus Loads & Equipment: 39,571 kWh
Other End Use: 0
Annual On-Sale Renewable Generation
PV: 142,871 kWh
Solar Thermal: 5,670 kWh
Biomass Electricity: 0
Biomass Thermal: 0
Other Renewable: 0
Total: 148,541 kWh
Peak Electricity Demand: 15,969 kWh
Peak Natural Gas Demand: 0
Peak Cooling: 363.63 ft2/ton
Connected Lighting Load:.96 W/sf
Data Sources and Reliability
Based on simulation? — Yes, Energy Plus
Based on utility bills? — Yes, Arizona Public Service — Jan.–Dec. 2012
Comments on data sources and reliability
We used utility bills to identify total kWh usage for the project. Lucid monitoring data was used for all other values. This is based on actual real-time monitoring data which looks at HVAC, Lighting, DHW, and Plug Loads all in real-time.
The DPR Construction office in Phoenix offers an array of features to enhance productivity and support active lifestyles. The fitness center gives employees full access to a wide array of gym equipment and the flexibility to utilize this equipment at any point during the day. The stresses of a busy schedule can make it difficult to find time to 'run to the gym' and this space eliminates the time and expenses typically associated with gym membership. The nap room is an opportunity to rest or relax during a long day and everyone is encouraged to use it as they feel necessary. The abundant natural light allows occupants to connect their circadian rhythms to the day and minimizes the strain typically associated with artificially lit spaces. The building's natural ventilation system provides adequate fresh air into the facility when outdoor conditions are appropriate and the buildings HVAC system exceeds the outdoor air ventilation rates required by ASHRAE Standards 62.1-2004 by over 30%; it can be adjusted to 100% outside air when necessary. Big Ass Fans are installed throughout to encourage increased or decreased air movement depending on thermal conditions. This allows the extended comfort ranges to still meet occupant needs and reducing the amount of mechanical ventilation necessary, taking advantage of natural ventilation or outside air.
A. Lessons Learned
Describe synergies that resulted from the strategies implemented.
Overall the project itself is a reflection of the synergies of the project strategies. Each strategy is clearly delineated in the project's design and its placement and materiality are based on optimizing performance and cost. DPR Construction has been committed to continuous improvement in all the building systems. They utilize the extensive system controls and real-time monitoring to tweak and adjust the buildings performance. Some of the follow represent a few of the lessons learned during operation. Fan Controls: DPR has been utilizing the Big Ass Fans to control airflow in the space. They can adjust the fans speed depending on the level of conditioning necessary.
Originally, the fans were seen as a mechanism to increase air flow across a person's skin, allowing for increased temperatures yet still providing adequate comfort conditions. This past winter, DPR discovered that decreasing the speed to very low levels can also benefit of the heating season. These low fan speeds push the stratified hot air at the ceiling down towards the occupants, further extending the comfort conditions in the heating season. Plug Loads: The significant efforts made by DPR during design and occupancy to address plug loads had a tremendous impact on the project. In high-performance facilities, plug loads often become the predominant load and last refuge of energy reduction in a facility. While many clients are unwilling to invest the time or money associated with these strategies, the result, a 38% reduction, is remarkable, and begins to speak to the economic benefits of these strategies. These results also speak to the power of engagement with staff and getting their buy-in and ownership of the overall project goals. Without their commitment to reducing energy use all year, these results would not have been possible. Dust: The natural ventilation strategies proved to have significant impacts on the builds energy usage but posed issues with increased dust in the building. As the green screen vegetation continues to mature, it will be interesting to see if this decreases.
In the meantime, DPR has employed a full time cleaning person to help them handle the daily cleaning of dust. The savings from the system more than accommodate this additional expense and the value of having the fresh air and connection to outside conditions far outweigh its removal. Not only does the DPR Construction Office reduce total water use by 67% and generate enough energy to make it a net positive facility, but it also characterizes the possibilities associated with deep energy retrofits and urban revitalization. If we are going to address the changes in climate seen today and in the future, our existing building stock must be transformed. The DPR Construction Phoenix Regional Office begins to demonstrate what that transformation looks like and speaks to the level of achievement building owners can have when they effectively communicate project goals and organize a diverse team to help realize them.
How did you measure or evaluate the performance of the building?
DPR Construction utilizes a real-time energy monitoring system develop by Lucid that gathers data from an extensive controls system designed into the project. This system measures energy use from HVAC, lighting, DWH, and Plug Loads and is evaluated on a bi-weekly basis. The data gives DPR the ability to adjust system performance to more optimum conditions and benchmark the data from one minute to the next; giving insight into user operation anomaly's. The project was fully commissioned to the enhanced commissioning level outlined in LEED-NC 2009. Quite a few adjustments were made during the commissioning phase and resulted in reduced energy use immediately. A survey issued by the Center for the Built Environment at UC Berkeley, was given to staff to evaluate the project performance relative to air quality, thermal comfort, daylighting, lighting quality and acoustics. The results of this survey were above the national average and demonstrated a clear benefit to the staff and the owner. A second survey was sent to staff related to Living Building Challenge Net-Zero Building Certification. Its asked two simple questions about the beauty of the space which demonstrated that over 90% of occupants felt the project was 'beautiful' to them.
Describe how the owner/client benefitted
DPR Construction benefited by having their project meet or exceed all of their project goals while coming in on-time, on budget. The short timeline for the project required weekly team meetings and this highly integrated process allowed for every strategy to be evaluated on price and performance immediately. Each week, decisions were made from the research over the prior week. The client was able to make quick informed decisions with little unknowns, helping to move the project along and ensure complete transparency in the process. The project results speak to this refinement. The design is about holistic integration. Each piece, each move, each material was placed exactly where it needed to be to get both performance and cost in alignment. DPR has also benefited in the value of the project from its employees. Survey results showed that a majority felt the space enhanced their ability to perform their job and found the space to be inviting and innovative. Additional benefits to the owner were increased public interest, publicity, awards, publications, business development and client engagement. The project is still a highly sought after event destination for community groups and private meetings.
- LEED Platinum Certification — July 2012
- Net-Zero Energy Building Certification — May 2013
- Energy Award, 2012
- AIA/APS Most Sustainable Project, 2012
- RED Awards (AZRE) Bronze Award - Reconstruction Awards, 2012
- Building Design and Construction Project of the Year & Best Office, 2012
- ENR-Southwest Excellence in Design Award - Commercial, 2012
- Environmental Design and Construction PRIDE Awards — Award of Merit — Commercial Office under 25,000sf, 2012
- IIDA Southwest Chapter Environmental Excellence — Crescordia Award (highest honor), 2012
- Valley Forward Association Green GOOD DESIGN Award — Green Architecture, 2013
- European Centre for Good Architecture and Urban Studies/The Chicago Athenaeum: Museum of Architecture and Design (international) Award of Merit — Energy, 2013
- IESNA-Phoenix First Place, Technology Award — Existing Commercial Building, 2013
- ASHRAE-Phoenix chapter First Place, Technology Award — Existing Commercial Building, 2013, ASHRAE-Region X
- National Institute of Building Sciences, Sustainable Buildings Industry Council (SBIC) Beyond Green™ High-Performance Buildings Award, 2013