The Path to Net-Zero Energy

How DPR's Living Labs are Pioneering Net-Zero Energy Building Certification

Net-Zero Energy features, clockwise from top left: 1. Rooftop photovoltaics 2. Solatubes 3. Expansive windows 4. Rooftop solar thermal water heating system 5. Solar chimney 6. LED lighting 7. AER-DEC sink and ultra low flush plumbing fixtures 8. Living walls with live plants 9. Building performance monitoring 10. Big Ass fans 11. Vampire shutoff switch 12. Operable windows and roll-up doors for fresh air and natural light

The Net-Zero Challenge

Introduction

In the ever-evolving sustainable design and construction arena, many owners and project teams are setting their sights on a goal that seemed improbable just a short time ago: creating commercial buildings that produce as much or more energy as they consume each year, known as net-zero energy buildings.

By the Numbers

200

DPR has worked on more than 200 LEED projects.


$6 Billion

Over the last five years, DPR’s revenue from green projects adds up to more than $6 billion.


45%

45% of DPR’s own offices are green, including nine certified LEED or targeting certification and four net-zero designed or certified, serving as living labs.

While this emerging trend is still gaining traction, DPR Construction has embraced the net-zero energy challenge in far more than just theory. Regional office projects in San Francisco, Phoenix, San Diego, Washington, D.C., Sacramento, Newport Beach and elsewhere demonstrate how the company’s core value of being “ever forward” is fulfilled through environmentally responsible spaces that benefit not only DPR’s own employess but also the communities in which they work.

In total, DPR has built four International Living Future Institute (ILFI) net-zero certified projects—the David and Lucile Packard Foundation corporate headquarters, as well as three award-winning net-zero regional offices in Phoenix, San Francisco and San Diego. DPR’s Washington, D.C. office, which opened in July 2016, is also targeting net-zero energy certification. These DPR offices are prime examples of how the company is helping to pioneer a movement that many expect will ultimately make net-zero energy the “new norm” in sustainable design and construction. More than just offices, these buildings serve as living laboratories that showcase the latest in sustainable concepts in a variety of regions and climates.

DPR Construction has embraced
the net-zero energy challenge

map of DPR net-zero projects

The Net-Zero Challenge

About DPR's Net-Zero Living Labs

DPR San Diego

Completed in 2010, the building served as the launching pad for DPR’s net-zero initiatives and laid the groundwork for future high performance, sustainable projects, in Phoenix and beyond. While it has garnered plenty of recognition for its appealing sustainable design and status as both the first LEED Platinum certified and the first net-zero energy office of its size in San Diego, the biggest payoff for DPR has been the improved quality of life and high satisfaction rating of the employees who work there. DPR purchased the 34,000-sq.-ft., 25-year-old industrial building office in 2008 and set to work transforming what was an ordinary suburban tilt-up office building into an extraordinary space that illustrates commitment to sustainability as well as employee health and welfare.

DPR Phoenix

The LEED®-NC Platinum, 16,533-sq.-ft. structure is Arizona’s first net-zero energy office building (NZEB), as certified by the ILFI Living Building ChallengeSM 2.1. Producing as much or more energy than it consumes, DPR’s Phoenix office was the largest commercial building in the world with the NZEB certification in 2013; it was only the second office in the nation to receive certification. While demonstrating the viability of attaining net-zero energy operations within a desert environment—a lofty goal in itself—the project also illustrates how a highly collaborative, experienced team can effectively transform an aging, underutilized structure located in an area of urban blight into a model for sustainable development and urban renewal.

DPR San Francisco

DPR’s San Francisco office is the first commercial office in San Francisco to achieve NZEB certification to date. By being both the owner and contractor for the renovation project, DPR was able to push the limits on its sustainability goals for the 24,010-sq.-ft. building and create a true living lab of sustainable business practices for San Francisco. As a one-of-a-kind building that is uniquely San Francisco, the office is inspired by like-minded clients that share a commitment to the environment, community and employees. The office serves as an event space where organizations can host events and learn about the most intelligent energy efficient technologies available.

DPR Washington, D.C.

Completed in 2016, DPR’s Washington, D.C. office is the fourth DPR office to target net-zero energy and the first of its kind in the D.C.-metro region. Rather than building new, DPR chose to renovate the 20,000-sq.-ft. space, which had previously been vacant for more than seven years. This decision emphasizes DPR’s commitment to environmental responsibility and to moving the industry forward, showcasing how a Class-C office space with an average skin system can become a net-zero, Class-A office in the Mid-Atlantic climate.

Net-Zero
Office Comparisons

EUIs14 kbtu/sf/yr26 kbtu/sf/yr23 kbtu/sf/yr29 kbtu/sf/yr (estimate)
DaylightingRooftop Solar tube fixtures (Solatubes)
Rooftop daylight harvesting light wells 
Daylight extension strategy – glass walls and reflective surfaces
Smart glass – Transitioning tint technology (RavenWindows and View Dynamic Glass)
LightingHigh efficiency and LED fixtures
Integrated Lighting and Zoning Design
Indoor Air QualityExpanded Occupancy Thermal Comfort Zone
Enhanced air circulation - High Volume, Low velocity ceiling fans (Big Ass Fans)
Passive ventilation – Large Volume/High Ceilings – Stack Ventilation
Evaporative Cooling – Shower Towers
Natural Ventilation – Operable Windows and Rooftop Monitors – Solar Chimney
Exterior Window Shading/Treatments – Green Screens
Indoor Landscaping – In Ground Beds/Living Wall
Passive Ventilation – Operable Skylight
Heating/cooling radiant sails
Dew point-dependent controls
Simultaneous energy recovery from hot and cold water loops
Dedicated outdoor air system
Controls and Building ManagementPassive Infra-Red Occupancy Controls
Time Controls and Shut-offs
Integrated Building Management System
Non-Occupied Energy Circuit Shut-off – Phantom Load Management Switch
Energy Consumption Awareness/ReductionEnergy End-Use Measurement Submeters
Building Energy Use Dashboard Display (Lucid Designs)
Occupant Plug Load Management & Measurement System – EnMetric
Low-energy and Energy Star equipment
Onsite Renewable Energy GenerationRooftop Photovoltaic (PV) Solar Array
Rooftop Solar Water Heating Array
Shaded Parking Photovoltaic (PV) Solar Array

Net-Zero Strategies

Sustainability Through Reuse

As a company that strives to be environmentally responsible, DPR sees an opportunity to transform buildings seemingly at the end of their lifecycles through reuse and renovation. Each DPR net-zero-energy-certified office uses different techniques to achieve its status, because technology, systems and equipment/products are constantly evolving; some of the technology and products available in 2014 were not available even a few years prior. 

Through the four DPR regional offices, as well as the corporate headquarters project for David and Lucile Packard Foundation, DPR recommends the following green strategies when thinking about net-zero projects: 

6 green strategies icons

Green Strategies

  1. Set Goals 
    Owners and occupants should set project goals, make them requirements and share them early on with all project stakeholders. These requirements should align with the company's needs and culture, the design and construction process, and the operation of the completed project.

  2. Monitor Energy 
    Building occupants can track their electricity, water and natural gas usage savings in real-time through monitoring software. Four DPR offices use Lucid Building Dashboard® to track sustainability goals.

  3. Use outside air to cool the building 
    Natural ventilation systems use outside air to keep buildings cool, reduce energy, and lower costs.

  4. Reduce use of artificial light 
    Expansive windows and natural light through strategically-placed Solatubes® reduce the need for electric lighting and associated costs.

  5. Generate energy with photovoltaics 
    Photovoltaics generate power from the sun to offset energy usage. Generating even one kilowatt-hour saves 300 pounds of carbon dioxide from being released into the atmosphere each month.

  6. Disconnect phantom-plug loads 
    Install a vampire shut-off switch to disconnect phantom-plug loads every night, saving money and energy.
2003

DPR’s LEED Silver Sacramento office was the first privately owned LEED certified building in California’s Central Valley.

2010

DPR’s San Diego office was the first commercial building to achieve both LEED-NC Platinum and net-zero energy status in San Diego.

2013

DPR's LEED-NC Platinum Phoenix office became the largest building in the world to achieve Net-Zero Energy Building certification from the International Living Future Institute's Living Building Challenge.

2016

DPR’s San Francisco office became the first certified net-zero energy commercial building in San Francisco.

2016

DPR opened its net-zero-energy-designed Washington, D.C. office in Reston, Virginia.

The Net-Zero Challenge

Documentation Requirements for Net-Zero Energy Building Certification

Through the ILFI Living Building Challenge program, DPR Phoenix achieved NZEB certification in May 2013, DPR San Francisco in January 2016 and DPR San Diego in May 2016. DPR Washington, D.C., which opened in July 2016, seeks to become the first net-zero energy commercial office space in the Mid-Atlantic region, and will submit for certification after one year of occupying the new office. 

The following are the four key criteria for certification:

images of documentation requirements for net-zero energy building certification

Documentation Requirements

  1. Site Imperative: Limit to Growth. 
    This imperative curbs a building’s contribution to sprawl. Effectively, buildings may only be built on greyfield or brownfield sites.

  2. Energy Imperative: Net-Zero Energy. 
    The primary focus of net-zero energy building certification, this imperative stipulates that 100% of the building’s energy needs must be supplied by onsite renewable sources on a net annual basis. The energy usage for a building must be documented by completing an energy usage table with monthly info gathered from tracking systems, energy bills for continuous 12-month period, and other supporting materials. Net-zero compliance can only be awarded after the building has demonstrated its compliance for at least a full year of occupancy.

  3. Equity Imperative: Rights to Nature. 
    This imperative ensures that the building does not preclude another building from achieving net-zero energy operation as a result of excessive shading.

  4. Beauty Imperative: Beauty + Spirit, Inspiration + Education. 
    The building must contain design features intended solely for human delight and the celebration of culture, spirit and place appropriate to its function.

Noteable Achievements

Sustainable Project Milestones

  • In 2003, DPR’s LEED Silver Sacramento office became the first privately owned LEED-certified building in California’s Central Valley.
  • Arizona State University Polytechnic Academic Complex won Engineering News-Record’s (ENR) first ever Best of the Best awards in the Green category in 2008.
  • The Michael J. Homer Science and Student Life Center project for Sacred Heart Schools, Atherton was the first ever to achieve LEED Platinum for Schools certification.
  • Digital Realty 1201 Comstock Web Hosting Facility was the first data center in California and one of the first in the nation to achieve LEED-CI Platinum.
  • In 2010, DPR’s San Diego office was the first commercial building to achieve both LEED-NC Platinum and net-zero energy status in San Diego.
  • Selected as ENR’s 2011 Editors’ Choice & Green Project of the Year, the Facebook Prineville Data Center Complex has the world’s best energy efficiency rating.
  • The ground-up LEED Platinum David and Lucile Packard Foundation Headquarters was designed for net-zero energy consumption. It won the 2012 Best of the Best Project award in the Green category.
  • In 2016, DPR’s San Francisco office became the first certified net-zero energy commercial building in San Francisco.

A Closer Look

DPR Phoenix

Selecting the Right Site to Meet Lofty Sustainable Goals

DPR had maintained a presence in Phoenix’s Camelback corridor since 1998. When it came time to renew its lease, the decision was made to find a new location that would bring the office into greater alignment with DPR’s goals and sustainable mission. Leveraging previous experience, the company decided to pursue a net-zero energy goal for the new Phoenix regional office.

Selecting the site was the first major challenge. The overriding objective was to find an underutilized, existing building in a highly accessible redeveloping area of Phoenix, close to public transportation, that DPR could transform through cost-saving, sustainable strategies to reduce its carbon footprint and benefit the community’s redevelopment efforts. In addition to showcasing the latest in sustainable and energy reduction features, the intention of the project was to demonstrate the value and impact that revitalization has on an urban environment.

The team soon identified a property that may have seemed an unlikely prospect at first glance: an older retail building, seemingly at the end of its lifecycle. Beneath the surface, however, the building’s potential was apparent. Most significant was its location in the heart of Phoenix’s Discovery Triangle redevelopment district, minutes from the airport and in close proximity to a light rail stop that services the downtown core, West Phoenix and nearby cities.

The building’s overall structure was sound and contributed to DPR’s goal to maintain as much of the original structure as possible. Ultimately 93.7% of the original shell and structure remained in place.

The Importance of a Highly Collaborative Team

DPR brought together the entire design and construction team, including architect SmithGroupJJR, sustainability consultant DNV KEMA Energy & Sustainability, mechanical contractor Bel-Aire Mechanical, Inc., DPR project team members, and various consultants and subcontractors, very early on to help identify and select potential sites and then provide input throughout design and construction.

Assembling the right team and then fostering a highly collaborative environment were key to the project’s success. Every team member was hand-selected for the design-build project based on his or her talents and demonstrated expertise delivering high-performance sustainable buildings. Innovation was encouraged, and pushing the limits of conventional approaches expected. The integrated team cultivated a strong sense of trust and was united in working toward a common goal.

The extremely fast-track timeline—10 months from start of design to completion in October of 2011—meant that ideas had to be presented, discussed and decided on immediately. The high-functioning team involved in this transformative project development process ensured that the building’s physical transformation was of the highest quality, and that the end product incorporated the most innovative, sustainable features possible.

During the construction process, sustainability was always at the forefront as well, with 78% of the materials removed from the site ultimately recycled. A goal was to use sustainability strategies that yielded a 10-year return on investment.

Modern Design Fits a Progressive Company

The project’s design reflects the “workplace of the future,” with DPR’s hallmark open office environment instead of traditional private offices.

The building’s modern and innovative aesthetic also takes a “do more with less” approach with sustainability in both building form and function. For example, a green screen with biomass wrapping the facades creates a secure and inviting outdoor courtyard environment for employees while also providing shade for the building.

While the building’s south and west elevations were largely left intact, large expanses of glass were added on the east and north facades to bring in natural light. Horizontal shading devices were used to minimize direct solar gain.

Inside the building, major design features include video conferencing rooms, a learning lab, a fitness room with shower facilities, a modern open kitchen and café area, and roll-up doors that lead to shaded patio areas.

Some of the other unique elements include:

  • A “Zen” Room with plush sofa and chair;
  • A conical Delta Room that represents DPR’s continuous drive to push the status quo;
  • An Innovation Room with sliding glass walls, whiteboard and bold colored reconfigurable furniture designed to inspire creativity; and
  • A prominently located 18-ft. wine bar, used as an impromptu gathering space for meetings, celebrations and conversation with clients and staff.
  • Inspired geomorphic shapes found in nearby desert canyons are reflected in the building design. A wrapped sculptural enclosure--the Delta room--in the conference space expresses DPR’s self-perform drywall expertise, utilized on this project, while the colors reflect the desert environment just outside. Strategically placed vertical green elements throughout the interior resemble a “landscape of saguaros” while functioning as message boards and power/data towers that break up the open space.

Overall, the project employed a variety of strategies to reduce energy while also creating a healthy environment for employees. A full 100% of spaces can have lights off during daylight hours and 75% have access to exterior views.

Some of the green materials incorporated include:

  • 97% of wood from Forest Stewardship Council (FSC) sources
  • 32.76% of materials were of recycled content
  • Low or no-VOC content for all finishes
  • Reuse of DPR’s existing built-in work stations, requiring only 14 additional stations to be built.

Major Sustainable Components to Achieve Net-Zero

At the heart of the project are the many sustainable elements that help the building both conserve energy and produce power needed to offset that demand. Every design consideration impacts the building’s overall performance, and every building component was carefully selected.

By the Numbers: Phoenix

140,000

A 78.96-kilowatt PV-covered parking canopy system generated 140,00 kilowatt-hours (kWh) of estimated total annual building electrical usage.


10

The office took ten months to build, from start of design to completion.


82

82 high performance daylighting Solatubes reduced artificial lighting usage by 90%.

There were a number of primary sustainable features in this building that were integral to achieving the net-zero energy goal. They include:

  • Solatubes® – The installation of 82 high-performance daylighting Solatubes, strategically positioned throughout the building, reduced artificial lighting usage by 90%.
  • LED Lighting – Since the building’s interior is lit by Solatubes during the day, a lifecycle cost analysis showed that interior LED lighting was not cost-effective for a 10-year return. LED lighting was deemed an ideal solution, however, for exterior site lighting that is programmed at night. By selecting LED fixtures for site lighting, the team was able to reduce the size of the building’s photovoltaic system.
  • Shower Towers – Four evaporative cooling-towers work in conjunction with the solar chimney to passively cool the building. The towers sense and respond to climatic changes, including wind speed and temperature.
  • Solar Chimney – An 87-foot long zinc-clad, roof-mounted solar chimney, said to be the largest of its kind in Arizona, supports the building’s passive cooling system.
  • Operable windows and roll-up doors – The project incorporated 87 operable windows along the building’s east and north facades, providing access to fresh air and natural daylight. Controlled by outside climatic conditions, they open gradually to adjust to ventilation needs of the space.
  • “Big Ass Fans” – Twelve eight-foot-diameter Isis® Big Ass Fans® promote air circulation and are integral to the building’s cooling system. Air movement allows interior temperature set-points to be increased while still feeling comfortable for occupants.
  • Vampire Shut-Off Switch – This particularly unique sustainable feature targets a reduction in energy consumption attributed to phantom loads – the energy consumed by a device even when it is turned off. This switch is designed to disconnect 90% of plug-loads at the end of each workday. The last person exiting the building is responsible for activating this switch. Nationally, phantom loads are estimated to account for nearly 6% of the nation’s energy consumption.
  • Photovoltaics – A key feature in net-zero energy buildings, photovoltaic systems are intended to make up the difference in energy needed to operate a building after all other measures to reduce the building’s energy consumption are exhausted. In the Phoenix office building, a 78.96-kilowatt photovoltaic-covered parking canopy system was designed to generate the 135,000 kilowatt-hours (kWh) of estimated total annual building electrical usage. During its first year in operation, it actually exceeded that goal and generated more than 140,000 kWh of electricity.
  • Lucid Building Dashboard system – In the long run, the success of a net-zero energy building puts some responsibility on the shoulders of the building occupants to monitor and, if needed, modify their behavior in order to maximize building performance. The Lucid Building Dashboard® system incorporated in this project shows in real-time how the building is performing in terms of energy production versus usage. It provides a visible reminder to employees of the connection between their behavior and building performance. This helps create a "Prius effect," in which employees become more motivated to meet goals.

A Closer Look

DPR San Diego

Modeling DPR's Net-Zero Energy Journey

For proof of how a net-zero energy building pays dividends over time when measuring both an owner’s return on investment and the building occupants’ satisfaction level, look no further than DPR’s own San Diego regional office building, which achieved NZEB certification in May 2016.

The project team had four primary criteria:​

  • Bring the outside in; take advantage of the climate and location by opening up the building to the outside. 
  • Create a net-zero energy office that serves as a model for other commercial building projects.
  • Maximize the building’s existing features and only use strategies that yield a 10-year return on investment to serve as a market case for sustainability.
  • Represent the company’s core values and respect the individual (in this case, DPR employees).

According to the Environmental Protection Agency’s Energy Star rating system, the new building performs over 97% better than similarly modeled buildings in the area in both use and climate zone. The building’s Energy Use Intensity or EUI (the unit of measurement that describes a building’s energy use) is a low 14, two-thirds lower than Title 24 standards. The mixed-mode HVAC system operates 79% fewer hours compared to a mechanically ventilated building. Water consumption was reduced by nearly half.

Achieving Net-Positive Results

Since its occupancy in 2010, the San Diego office has ended each year “net-positive” as the roof-mounted 64 kW-AC photovoltaic system has generated more than 12,000 kilowatt-hours more than the office consumed annually.

The building is also on track to return all of its premiums related to sustainable construction well ahead of DPR’s 10-year goal.

By the Numbers: San Diego

97%

The San Diego office performs over 97% better than similarly modeled buildings in the area, in both use and climate zone, according to the EPA’s Energy Star rating system.


79%

The mixed-mode HVAC system operates 79% fewer hours compared to a mechanically ventilated building.


12

A building dashboard features data from 12 electrical sub-meters, PV system, natural gas meter and indoor water meter.

So how did it achieve those results?

  • Capitalizing on climate – DPR’s primary strategy was to capitalize on San Diego’s famous temperate climate to help deliver a majority of the building’s cooling and ventilation requirements. They incorporated a system of motorized operable windows and roof monitors to benefit from prevailing breezes and to help achieve stack ventilation. The operable windows and monitors create the effect of a solar chimney within the structure, providing passive ventilation to the space.
  • Solatubes – To reduce dependence on artificial light, DPR enlisted a comprehensive natural daylighting strategy that incorporates 40 Solatubes, south-facing roof monitors, along with energy-efficient lighting fixtures and controls. Water savings are derived from high-efficiency fixtures, low-flow rate metered faucets, and climate controlled irrigation. Natural gas consumption decreased from on-site thermal water heating.
  • Open design – Breaking down any barriers to collaboration, the building’s wide-open design and numerous amenities foster interaction and teamwork. There are 11 conference rooms that include the Big Kahuna with La Cantina segmented sliding doors that open to an outdoor patio; the audio-visual loaded training center, capable of hosting a sit-down event for 90 attendees; the circular Delta room; Pipeline, the 16-person video conference room; and Cave Rock, a space devoted to BIM technology, among other things.
  • Employee engagement in building performance management – Employees stay informed and engaged in helping facilitate the office’s energy and water consumption with easy viewing of a Building Dashboard featuring data from 12 electrical sub-meters, photovoltaic system, natural gas meter and the indoor water meter.

Award-Winning Design

The open office space features 14-ft.-high exposed ceilings accented by artistically designed material pieces that resemble the sails of boats and diffuse light, while the ocean-related theme is further reinforced with four custom surfboards in the lobby representing DPR’s core values. A 14-foot wine bar in the heart of the office space is designed to bring guests and employees together.

DPR’s San Diego regional office space has received several awards, including a California Construction (now ENR California) 2010 “Best of the Best Green Project” award as well as San Diego Architectural Foundation “Orchid for Sustainable Design” award that same year. For DPR and its San Diego employees, the most valuable reward, however, has been creating a highly successful, high performing net-zero energy model that has advanced the company’s mission to be a leader both as a green builder and as a corporate citizen.

A Closer Look

DPR San Francisco

After outgrowing its office space in 2014, DPR’s San Francisco regional office moved into an existing two-story 24,000 sq.-ft. structure at 945 Front Street, a block away from the Embarcadero.

The office includes space for 50 DPR employees, 20+ subtenant employees, conference rooms, a central atrium, break area, kitchen and fitness center. With a large training room, and open-concept lobby for holding events, the DPR office is a social space that has been a part of multiple sustainability evenings, conferences, tours and collaborations. The building has incorporated a publicly accessible building dashboard and a LEED dynamic plaque.

Guided by lessons learned from the company’s net-zero energy facilities in Phoenix and San Diego, DPR created its San Francisco office with the following goals:

  • Build San Francisco’s first commercial net-zero energy project in the city’s cool and foggy climate.
  • Create a high-performance, net-zero energy space on a traditional budget for a Class A+ office space, specifically for under $200/sq. ft. 
  • Create a living lab of sustainable systems and practices that could be monitored, adjusted and replicated.
  • Maximize efficiency and total cost of ownership, by allowing for performance monitoring throughout the lifecycle of the building.

Unique Challenges in the City by the Bay

The San Francisco team was challenged with the task of retrofitting a building to net-positive energy on a budget, within a tight schedule, and in the urban environment of San Francisco. With no space between buildings, the site’s taller neighbors cast shadows over the PV system, which also had to be “right-sized” for San Francisco and its uncertain foggy weather. This was a stark contrast from the consistently warm locations of San Diego and Phoenix.

The project team first set out to achieve net positive energy performance by reducing building loads to a target EUI, which could reasonably be offset by PV on the roof (24 kBtu/ft2·yr [272.6 MJ/m2·yr]). This firm goal was set and agreed upon by all stakeholders early on and enabled the team to find innovative strategies to overcome challenges while upholding the overall project goal. Being surrounded by other buildings on three sides prevented passive design strategies such as natural ventilation and full daylighting from being options.

Competing needs between roof space for photovoltaic panels and skylights, and the need to upgrade the structure to hold the additional weight of insulation and PV panels, were all challenges for achieving net zero energy design at non-premium construction costs. The project ended its first year with a EUI of 20.4 kBtu/ft2·yr (231.7 MJ/m2·yr), significantly lower than the code baseline of 49 kBtu/ft2·yr (556 MJ/m2·yr) determined using energy analysis software and less than the production on the roof of 24 kBtu/ft2·yr (272.6 MJ/m2·yr).

On the Road to Net-Zero

The integrated design build/assist process by which the product was delivered can be considered the project’s most innovative component. Stakeholders were involved in weekly meetings, enabling the use of rapid, collaborative analysis to determine the most cost-effective way to meet the energy target. This complete team allowed the project to move quickly, as demanded by tenant improvement work, and to be cost effective while still meeting the strict net-zero energy goal and incorporating additional costs such as significant structural upgrades.

An integrated design allows for simple, coordinated design solutions that can be easier to operate/troubleshoot than technology-focused building solutions. This concept was part of the design process for DPR from project inception through commissioning. As net-positive buildings have to be monitored and operated continuously for a minimum of a year to be certified, it was important to provide systems that can provide clear feedback and easy monitoring for operators and designers. A building that is hard to control and has complex systems can have an amazing design, yet also result in the building costing more to operate and troubleshoot, potentially offsetting the benefit in energy cost saved. For this reason, the design strategy was to use simple, efficient, off-the-shelf systems such as ceiling fans, tubular daylighting, a whole building “kill switch,” and an increased thermal operative temperature range.

In eight months, DPR, design firm FME Architecture + Design, Oakland-based consulting firm Integral Group and 58 other essential partners, researched, designed, permitted and built a highly-efficient, modern workplace with a number of innovative sustainability features including:

  • 343 SunPower 345-watt photovoltaic (PV) panels to produce a 118kW renewable energy system and provide power throughout the office
  • Complete structural renovation and roof replacement to support the PV system
  • Rooftop solar thermal water heating system
  • 19 Solatube750 DS Daylighting Systems
  • 8 Velux solar-powered, automated operable skylights over the atrium
  • 2 large atrium skylights that were retrofitted with View Dynamic Glazing to control heat gain and diffuse natural light
  • 9 8-foot Essence and 4 Haiku® Big Ass® Fans that efficiently promote air flow within the office
  • 3 living walls installed by Habitat Horticulture in addition to a living wine bar – live plants growing beneath the glass bar top
  • Reclaimed redwood from the deconstructed Moffett Field Hangar One in Mountain View, Calif. and reclaimed Douglas Fir from piles salvaged from the San Francisco Transbay Transit Center Project
  • AER-DEC Sink and Ultra-low flow and flush plumbing fixtures by Sloan Valve Company
  • Honeywell Command Wall Touch technology incorporated BMS System
  • First deployed LEED Dynamic Plaque assisting with tracking building performance

Results: From Electric Bills to Credits

Beyond the cost of design and construction of a building, the long-term effects on total cost of ownership (TCO) are perhaps the most significant outcomes of creating a net-zero energy building. Only 10% of the cost of a building (over its lifetime) is upfront from design and construction, but the building’s operating cost (repairs, maintenance, etc.) is the other 90%.

By the Numbers: San Francisco

$11,000

DPR received a “bill” from PG&E with a credit of almost $11,000 as a result of the energy it put back into the grid within a year.


30%

Net-zero ROI is 30% within ten years.


3

The San Francisco office features 3 living walls, in addition to a living wine bar.

System Performs Better Than Modeled, Resulting in 20% Net-Positive Energy

  • In its first year of occupancy, the San Francisco office used 13% less energy than predicted; design estimates forecast energy consumption at approximately 151,000 kWh, but the building used only 131,000 kWh because of its highly efficient PV panels. 
  • Due to the PV panels, the office is actually 20% net positive energy at the end of its first year of occupancy. Emissions for the building without PV’s would be about 20 tons of carbon per year. With the PV’s, it is operating at a net positive rate of 5.84 tons/year. 

Net-Zero ROI is 30% within 10 Years 

  • Based on DPR's green project work, the cost premium for building an energy-efficient project ranges from one to 12%, depending on the building type. However, the return on investment for energy efficiency ranges from 5% to 12% within 10 years. 
  • Although the cost premium for constructing a net-zero energy building ranges from 5% to 19%, the return on investment for net-zero energy is about 30%.

A Bill Becomes a Credit

  • DPR received a “bill” from PG&E with a credit of almost $11,000 as a result of the energy that it put back into the grid within a year.

Reduce Carbon Emissions by One-Third Average

  • DPR radically reduced its projected total carbon emissions over a 20 year period. The building also reduced its carbon footprint by 37% by the end of 2015. The goal for design energy use intensity, which is energy per sq. ft. per year, was 24 and the actual was 20.3. The average EUI in California is around 60, so the San Francisco office is using only one-third of the average.

Creating a Cost-Effective, Replicable Model 

  • DPR’s priority was designing a building that is not only sustainable, but also cost-effective and replicable. This project showcased that energy efficient and renewable systems have reached a nearly cost neutral tipping point. 
  • PV prices have dropped to an average cost of $3.10/watt (installed) in the Bay Area, down from $9-10/watt in 2008. The mechanical cost was $20.70/sq.ft, which is lower than the national average of $23/sq.-ft. for office buildings. Overall, the building cost $160/sq.-ft. and the PV and structural roof upgrades to support the PV cost $40/sq.-ft., slightly higher than other projects in the area, but the estimated energy savings per sq. ft. are predicted to bring down the cost to lower than average in the area. Costs were further offset by taking advantage of incentives and rebates, such as the California Savings by Design program.

Lessons Learned

This project shows that you can have comfortable, net-positive buildings even while using active systems for heating and cooling needs. The project taught the team that net-zero performance can be achieved without going over budget and that design, construction, and operation issues are ultimately caused or solved in the non-technical sphere. Every 20 to 30 years the building and its systems need a renovation and refresh. Every refresh is an opportunity (and a code obligation) to replace systems and install current technologies.

  • Design Assist and Collaboration. When designing in a vacuum, engineers are unaware of real-time cost implications. Rapid pricing feedback coupled with energy analysis of decisions assists in high performance building design without added cost.
  • Evaluate Your Structure First. One of the largest costs associated with net zero was having to upgrade the roof. This needs to be looked at early in design.
  • Cost of Solar. With the price of solar dropping dramatically over the last five years, it isn’t necessarily cost-effective to “over-design” for energy efficiency. In many locations, projects no longer have to design “net-zero ready” buildings, but can install solar systems for opening day.
  • Energy Metering. Prices continue to drop for metering. However, it’s hard to justify detailed metering when the energy bill is negative. “Insurance” PV can offset energy issues and be less expensive than traditional M&V fees. Limit metering to just major loads (panels) and major equipment—skip the printers and kitchen equipment, and make sure data is easy to access and monitor.
  • Cutting Shelf Technology. LEDs, VRF, DOAS and other simple off-the-shelf systems reduce the complexity of the building, reducing maintenance.
  • BMS. On smaller projects, design teams should consider specifying that equipment with onboard controllers not be fully controlled by the main BMS to reduce system complexity and cost.

A Closer Look

DPR Washington, D.C.

Accessibility was the main driver in moving the Washington, D.C. office from Falls Church to Reston, Virginia. A study on employee locations and commutes, along with the nearby metro line and proximity to the airport made Reston an easy choice. With so much vacant office space in northern Virginia, the team didn’t see a need to build from the ground up. DPR chose to renovate the 20,000-sq.-ft. space, which had previously been vacant for more than seven years, but was close to public transportation, the town center and nearby recreational trails. This decision emphasizes DPR’s commitment to sustainability and to moving the industry forward, showcasing how a Class-C office space with an average skin system can become a net-zero, Class-A office in the Mid-Atlantic climate.

The team set the following goals for its project to be considered a success:

  1. Create an office of the future that invigorates our people and encourages creative work practices.
  2. Do the right thing by incorporating sustainable strategies that contribute to the health and wellbeing of the environment and our people.
  3. Make data-driven decisions based on cost-analysis, payback studies and team member expertise.
  4. Build a living laboratory where we showcase technologies, products and systems, along with a robust educational program.

Environmental Responsibility

DPR's Washington, D.C. office is pushing the envelope when it comes to sustainability. Targeting LEED-CI v4.0 Platinum and designed to be net-zero energy, the space incorporates a variety of sustainable elements, including:

  • HVAC – Aiming for net-zero energy, the office first had to reduce their current energy loads as much as possible, using fan-powered terminal units, allowing simultaneous heating and cooling of different areas in the office. 
  • Radiant sails – In select rooms, DPR Washington, D.C. used Radiant Sails, a system which transforms the centuries-old technology of radiant heating and cooling, into a modern architectural element that is also an extremely energy efficient way to provide thermal comfort to its occupants.
  • Natural daylight – the entire 20,000-sq.-ft. area is illuminated by more than 24 SolaTubes that allow a tremendous amount of natural daylight in, while using very little energy for lighting throughout the day.
  • Lighting controls – The LED lighting system, combined with a robust control, automation, and sensor system (donated by Watt Stopper) provides a consistent level of lighting throughout the day, while maximizing energy savings. Power outlets also use a phantom load-reducing system that will eliminate all loads from devices not in use after 8 pm.
  • Photovoltaic system – A rooftop 147 KW solar array is designed to include 10% more energy than will be required to achieve a net-zero certification through the ILFI program. The Sun Power Helix photovoltaic system will be one of the first of its kind on the East Coast.
  • Water efficiency – A highly efficient rooftop solar hot water system provides hot water for all domestic uses, while DPR partnered with Sloan to provide extremely water efficient fixtures in the restrooms and shower facilities.
  • Materials – All finished materials in the space (carpet, wallcoverings, tiles, etc.) are certified as Cradle to Cradle. The most notable architectural element throughout the space is the reclaimed wood taken from barns in Connecticut and the eastern shore of Maryland, and installed by our own self-perform carpenters. 
  • Connection to the outdoors – Adjacent to the kitchen, the office offers access to the outdoors for employees to take a break and get some fresh air, or let the fresh air in. The office has a LED stoplight, programmed to let employees know if the outside weather conditions are acceptable to keep the door open. 

Creating a Living Laboratory

By the Numbers: Washington, D.C.

24

Number of SolaTubes installed in the space for natural daylighting.


432

Number of PV panels installed on the roof.


85

Number of LEED points being targeted to reach LEED-CI Platinum certification.


As a living laboratory, it was important to the team to be able to educate others, while also continuing to monitor its progress against its environmental goals. 

  • Lucid Dashboard – A Lucid dashboard provides real-time information related to energy and water consumption, as well as energy produced by the PV array, so the team can visually see what is working and what needs tweaking in pursuit of net-zero energy certification.  
  • Showcasing Products – New products throughout the space are used as a way to educate clients and design teams on what is possible in an office of this scale. For example, the team installed four different finished concrete options, which allow owners and architects to see what different finished products look like and how they hold up to normal office wear and tear. Other technologies, such as the Radiant Sails, were placed in key, visible spaces so visitors have the opportunity to compare to more traditional systems. 
  • Mechanical Room – As a technical builder, providing a glass window into the mechanical room will allow DPR Reston an opportunity to educate visitors and its own staff about the functionality of office’s complex MEP systems.

The Path to Net-Zero Continues

Conclusion

As we evolve as a society, so does our built environment. Building net-zero energy offices is now realistically attainable from design, construction, budget and total cost of ownership perspectives. DPR’s four living labs not only showcase the latest sustainable concepts in a variety of regions and climates, but offer the unique opportunity for DPR to study and experiment with what makes the buildings most efficient over time. Leading the way in sustainability and pioneering the net-zero movement, DPR hopes to continue sharing updates and lessons from our net-zero projects to show both industry peers and customers that net-zero construction is a viable option to both save money over time, as well as make a positive impact in this world we all live in.  

Updated September 29, 2016

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About DPR

DPR CONSTRUCTION is a unique technical builder with a passion for results. Consistently ranked in the top 50 general contractors in the country over the last 15 years, DPR is a national commercial contractor and construction manager specializing in technically challenging and sustainable projects—of all sizes and complexities—for the advanced technology, healthcare, life science and corporate office markets.