EPA Region 8 Headquarters
North façade and view of upper curtain wall
- Building Name: EPA Region 8 Headquarters
- Building Location: Denver, Colorado USA
- Project Size (ft², m²): 248,849 RSF
- Building Type(s): Leased Office Building
- Project Type: New Construction
- Delivery Method: Two Phase SFO - Design/Build
- Total Building Costs: $90 million
- Site Costs: $12.5 M
- Building Architect/Project Team/Contacts:
- Developer: Opus Northwest, LLC
- Tenant: U.S. Environmental Protection Agency
- Design Architect: Zimmer Gunsul Frasca Architects LLP
- Architect of Record: OPUS A&E
- Consulting Architect: Shears Adkins Architects, LLC
- Mechanical/Electrical/Plumbing: Syska Hennessey Group, Inc.
- Blast Engineer: Hinman Consulting Engineers, Inc.
- Structural Engineer: KPFF Consulting Engineers, Inc.
- Security Consultant: Kroll, Inc.
- EPA's LEED® Review Consultant: Ensar/RMI
- LEED® Consultant: Architectural Energy Corporation
- Project Contact Person: Cathy Berlow, EPA
A. Project Description
EPA Denver's location in the LoDo district near the pedestrian avenue and public transportation
The design and construction of the new Environmental Protection Agency (EPA) Region 8 Headquarters in Denver, Colorado came as a result of outgrowing a leased space and having staff displaced over 23 floors in two separated towers, in the Denver Place building in downtown Denver. Additionally, the previous situation presented security risks and the building's character did not reinforce EPA's core mission of sustainability. Moving to a new building created the opportunity to consolidate EPA's staff on fewer floors, increase building security, and emphasize sustainability through the building's design, construction, and operations. The new Headquarters is located at a prominent location in the Lower Downtown (LoDo) Historic District on the 16th Street Mall, a bustling pedestrian avenue, and across from Union Station—currently being renovated as an intermodal transportation hub for Denver. The site, chosen from offers for 5 sites, provided a prominent location and access to both the 16th St. shuttle and light rail. The site was formerly a post office, and a postal annex that still remained on the site that was demolished in order for the project to proceed. GSA secured an assignable option for this site for one year which gave GSA one year to award the project to a developer, who would then be mandated to purchase the assignable option. The project was completed in November 2006.
B. Project Goals
Overall Project Goal/Philosophy
At the time of award, it was intended and required that the new Headquarters building achieve a LEED Silver certification and an Energy Star rating, and follow EPA's comprehensive procurement guidelines. Selection criteria were established for various phases of the project. The first step in the selection process was to identify and secure a site located in the Central Business District, sufficient in size and close proximity to mass transit. The second phase was broken into two parts, team qualifications and then short-listed team building design. The SFO included detailed lease terms, technical specifications for architectural, mechanical, and electrical components, and a detailed program of requirements. This included and required 300,000 gsf of space with approximately 248,849 rsf of office space, 40 secured parking spaces, and 70 secured bike spaces, as well as ground level retail space and a loading dock, with a minimum 25,000 sf floorplate. The Region's criteria for the second phase were sustainability, security, and schedule. These requirements also addressed design, achieving a better workplace, building operations, and price.
Increase security features and blast resistance in the context of sustainable design features to meet GSA medium level security, blast-proof envelope. Utilize Crime Prevention through Environmental Design (CEPTD) principles, especially along the historic streetscape.
The developer and his team were required to achieve a minimum LEED Silver level and Energy Star certification within 14 months of reaching 95% occupancy. The developer is also required to maintain these certifications through out the lease term or be penalized with rent reductions until the certifications are attained. Best practices were sought for energy conservation, water conservation, resource conservation, and indoor air quality. EPA also pursued sustainability beyond the scale of the building by trying to reduce their reliance on paper and implementing an electronic equipment recycling program.
To respond to the neighborhood historic context and the urban environment, while respecting the local surroundings. Create a pleasant, cohesive, more productive, and well-lit office environment for the employees.
To meet or exceed all of the current accessibility codes; provide pedestrian-friendly access to the light rail system, buses, and bicycle riding opportunities located in LO-DO district.
To bridge between the Lower Downtown (LoDo) historic low-scale neighborhood to the south and the more modern development area to the north with modern lofts and commercial high-rise buildings. In addition, expressing the buildings' goals for sustainability to the public on the exterior and to tenants on the interior.
To construct the new facility within the costs established by the lease using a combination of age-old strategies for responding to the natural environment with state-of-the-art building systems to reduce energy use by 30%.
Historic Preservation Goal
To effectively address and respond to the requirements and concerns of the Lower Downtown (LoDo) Design review Board for paving patterns, street furniture, cornice heights, fenestration, density, setbacks and ground level retail use requirements.
Design a building that would allow EPA to consolidate its 850 staff on fewer floors; enhance occupant health, well-being, and productivity. The SFO required 250,000 gsf with 231,281 to 232,000 rentable square feet.
Other Significant Aspects of the Project
See the EPA Region 8 website.
Overview Of Process
Building under construction
Several teams were established for the project and each team developed a regular communication system in order to facilitate an efficient and effective outcome and to coordinate effectively. In addition to the design experts on the development team, GSA and EPA sought advice from the technical staff of EPA, a private sustainability consultant, and the National Renewable Energy Laboratory (NREL).
The core team consisted of Opus Northwest, LLC as developer, contractor, and owner, Zimmer Gunsul Frasca (ZGF) as the design architect and design LEED expert, Syska Hennessy as daylighting, energy, mechanical, electrical, and plumbing engineers, KPFF as structural engineer, Hinman Consulting as security and blast consultant and Architectural Energy Corporation (AEC) as the construction LEED expert and preparer of the final LEED documentation submittal to the U.S. Green Building Council (USGBC). Opus's strategy included the formation of a team in which every team member acted as a LEED design consultant. Shears Atkins, a local architecture firm with knowledge of LoDo's entitlement and design guidelines, was involved for the entitlement phase. Jim Blackledge of EPA's Region 8 was hired to manage the local activities for design, construction, and occupancy. Blackledge put together internal teams on a volunteer basis to make decisions on many aspects of the project. For example, a team of ten EPA staff conducted market research and environmental evaluation in order to make recommendations for furniture, weighing decisions such as wheatboard versus urea formaldehyde-free composite wood. EPA also created a mockup of a Herman Miller workstation in their existing office to solicit reactions from the staff. The reaction to the workstation size and materials was positive.
The project team's activities centered on communication of technical information as business benefit or cost-benefit scenarios. They conducted extensive research on opportunities and focused on remedying anticipated issues. The team pursued and was awarded a federal energy management grant from the U.S. Dept of Energy to advance the energy systems decisions.
One unique example was the proposed water-efficiency measures which required the cooperation of local agencies like the Department of Health and the Wastewater Management Division.
Denver EPA Headquarters, Conceptual rendering
The team was required to register the project with USGBC during design development and provide an updated scorecard and energy calculations at each phase. Developer teams were required to present a complete conceptual design package including:
- 1/8" floor plans, sections, and elevations, including material notations
- Exterior rendering, site, and landscape plan
- Materials board for exterior and common areas and list of core finishes
- Narrative and basis of design for building systems and how they will meet Energy Star criteria
- LEED scorecard showing at least 33 points and all prerequisites
- Construction waste management plan
- Explanation and analysis of how the design meets the SFO criteria and upgrades beyond the SFO standards.
The site offered several opportunities and constraints that shaped the design of the building and defined the design activities. It is a prominent corner site in a pedestrian-friendly historic district, across from a future public plaza and there were additional requirements and concerns of the Lower Downtown (LoDo) Design Review Board for paving patterns, street furniture, cornice heights, and fenestration detailing that needed to be addressed. Additionally, the urban setting required full buildout to the sidewalk and commercial and retail space on the ground floor as well as a desire to reflect the local pattern of a mid-block break, with alleys bisecting blocks.
The OPUS design team began by studying several massing options, all of which were 9 stories high and approximately 250,000 sf and had the same proportions of brick and glass for the exterior skin. Four massing options were modeled using Ecotect software to create rough energy calculations including heating and cooling per month. A sample level was studied to examine daylight distribution across the floorplate. A matrix of the results of the studies showed the advantages and disadvantages of each massing scheme, but with no clear winner. One scheme included an atrium which responded to the programmatic desire to accommodate EPA's all-hands meeting of 850 staff, while letting daylight into the center of the building. The atrium scheme was considered to offer the best combination of energy efficiency and daylighting.
Interior office corridor overlooking atrium; Atrium sails control daylighting, solar gain, and glare
Upon their selection of the basic concept of a square building surrounding an internal atrium, the team next looked more closely at the site and environmental influences. Because of the 45 degree rotation of the street grid in LoDo, the conditions were considered to be the most difficult for daylighting. A response to this and the prevailing winds from the north was a concept of two differently articulated L shapes wrapping an atrium. The southeast and southwest legs deal with the daylight and solar gain, while the northeast and northwest legs were designed for wind. The north leg is nine stories high and the south leg is eight which allows for a roof garden on the south leg that is sheltered from the wind. A break between the Ls at ground level created a corner entry facing the new plaza at Union Station. The building's glass upper stories rise out of a brick base, with detailing and cornices that respond to the historic context and respect the surroundings.
The curtain wall design was modified for each façade with an emphasis on responding to environmental conditions while managing the cost of the system. The team worked carefully to balance sustainability and construction costs, which were a prominent issue, according to John Breshears, since it is a developer building.
The team was required to provide plans for final commissioning, indoor air quality, and construction waste management at the completion of the construction documents phase. During construction, they had to provide information on the volatile organic compound levels for all interior finishes, a monthly Construction Waste Management (CWM) report, EPA Green report documentation, monthly construction photos, and quarterly reports on recycled content.
During weekly construction meetings, the schedule was reviewed and followed by onsite inspections with GSA and EPA. Monthly construction reports were provided to GSA updating status on schedule, weather conditions, LEED data collection status, and construction photos.
Additionally, biodiesel fuel was used to power construction equipment. It was the first construction site in Colorado to use an alternative fuel to power the equipment. The biodiesel fuel source was local Canola plant oil and was considered to address deterioration of air quality. The use of the fuel was acknowledged by local and national politicians who also promoted state agriculture, so there were additional benefits as a result of the extra attention brought to that effort.
Waste management onsite during construction
The team is required upon construction completion, to provide LEED documentation, final reports for CWM, operations plan, lead in drinking water testing, IAQ testing, and final commissioning.
Post-Occupancy Evaluation Activities
The developer will submit annual reports on recycling operations and quarterly energy use reports, and GSA will have read-only access to a graphical user interface for data collection.
Information and Tools
Products and Systems
Exterior sunshades were a combination of a horizontal 20" perforated metal shade with an 11" fin. This choice of metal was made in order to balance performance—enhancing daylight, preventing solar gain, and controlling low-angle glare in the morning and afternoon—with construction cost and blast security.
Interior light shelves were incorporated on the south façade.
The building's roof is an EPDM membrane with a high-emissivity acrylic coating. This particular coating holds up better and is preferred by the roofing companies that provide the roof warranty.
The building's modular green roof system is planted with sedum and will reduce storm water pollution, minimize heat-island effect, and absorb carbon dioxide.
The Green roof was created to address water quality and energy conservation using a modular built-up system consisting of 4" deep plastic trays that sit on top of the roof membrane. Although the system added cost to the roof assembly, it will allow for planting of a few varieties of sedum and experimentation is ongoing with other types of plants. The roof was created to primarily relate to the LEED credit for avoiding heat islands, but the team conducted extensive work to have it apply to the storm water management credit also and was sized accordingly at 19,200 sf. The module trays are located on three terrace levels. Green roofs have numerous environmental attributes including: improving water quality runoff, reducing sewage system loads, reducing heat island effect, filtering air pollutants, mitigating smog formation, providing wildlife habitat, reducing building energy expenditures and improving urban aesthetics. From an economic standpoint, green roofs have a longer service lifespan than conventional roofs. They decrease costs associated with installation of infrastructure and related retention reservoir. Life-cycle costs between conventional and green roofs are comparable but the initial installation cost of a green roof is two times higher than a premium quality conventional roof. Other economic benefits to the building include: enhanced resale value, increased occupant comfort, increased worker productivity.
The building's mechanical system was designed for energy efficiency and increased ventilation effectiveness. The system was originally designed with waterside/floor by floor AHU but changed to a more energy efficient centralized rooftop air handling unit with air-side economizers.
Cooling is provided by a chilled water distribution system with variable-speed chillers and centralized rooftop air-side economizers.
The structural system is based on a post-tensioned flat slab with expressed beams on a 5' module. It ended up being a pan joist system.
Curtain wall design was modified for each façade with an emphasis on responding to environmental conditions while managing the cost of the system.
Photovoltaic array on south corner of roof is designed to produce 10 kWh during peak sun.
A 10 kW photovoltaic solar array was installed on the roof of the building.
Other Sustainable Strategies:
- Recycling & Waster Reduction programs
- Floors: recycled tires, natural cork
- Carpet: recycled content 8%–35%
- Acoustic Tile: recycled glass
- Wall recovering: recycled fabric, bamboo
- Countertops: local stone, recycled glass, aluminum scraps
- UItra Low-Flow Lavatory
- Low-Flow Showers
- Low-Flow Sinks
- Water Free Urinals in men's bathrooms (Potential savings = 360,000 gallons per year)
- Dual Flush toilets in women's bathrooms
Energy Use Description
The energy requirements for the building were approached from a whole building design perspective instead of from just an HVAC standpoint. This was very innovative and fairly new to the team as an approach to consider for this project. A detailed computer simulation was performed using eQuest building energy simulation program, developed to calculate hour-by-hour building consumption over the entire year using weather data for the specific location.
TestMarc was hired to perform Commissioning for the LEED energy and atmosphere requirements. The efficient mechanical systems, use of free cooling, daylighting, shading, and underfloor air system contribute to the estimated 35% energy savings. No HCFCs or halons were used in equipment. EPA agreed to purchase 100% of their power from renewable sources to achieve LEED credit 8 which addresses green power and to achieve an innovation credit.
The building is predicted to have an aggregate energy usage of 47.5 kBtu/(sf-yr), exceeding the ASHRAE 90.1 1999 baseline performance by 39%. The performance is also well below the GSA target of and average 55 kBtu/(sf-yr) for its entire portfolio. The main energy-efficiency design features of the project include:
- Building form that responds to climatic forces to enable maximum daylight penetration
- High-performance glazing and building envelope design
- Daylight redirection and control devices optimized for daylight harvesting coupled with daylight responsive lighting controls
- Optimized insulation levels
- External solar shading devices
- Energy-efficient lighting and reduced lighting power density
- Occupancy sensors
- Variable-speed drives for chiller and pumps
- Premium-efficiency motors
- Under-floor air distribution
- Air-side economizer
- Demand-controlled ventilation (CO2 monitoring)
- Carbon-monoxide-controlled parking ventilation
Annual on-site renewable generation
PV 10 kWh array on roof
Data sources and reliability
Based on simulation? Yes
Based on utility bills? No
NOTE: Additional energy data to be supplied at a future date.
Indoor Environment Approach
Elevator corridor showing use of materials with low or no VOCs such as carpet, paints, and wood products.
A variety of features were integrated into the building which improves the indoor environmental occupant quality. To achieve the IAQ prerequisites, the project met the ASHRAE 62-1999 ventilation air quality standard and is a non-smoking facility. The under-floor air system provides increased ventilation for LEED credit 2 and individual control to achieve part of credit 6.2 requirements also resulting in which results in a very high air change effectiveness. Additionally, carbon dioxide monitors were integrated to validate proper ventilation. Credit 3, which is Construction IAQ management plan during construction, was achieved through construction practices and a pre-occupancy flush-out.
Materials such as adhesives, paints, carpets, and composite wood products that have low or no volatile organic compound (VOC) emissions were specified to achieve LEED credit 4. Walk-off mats and exhaust requirements for janitor's closets and copy areas were provided for indoor chemical and pollutant source control.
Operable windows were not proposed due to concerns about air pollution and mechanical system operational control. The mechanical system was designed to achieve thermal comfort and the building facades provide sufficient daylight and view to meet the requirements of LEED credit 8 of diffuse sunlight to 75% of the space and outdoor views for over 90% of the spaces.
A. Lessons Learned
Office cubicle design allows for natural daylight to penetrate into the work space.
Design-build and design excellence should not be mutually exclusive. If excellence in sustainability is a project goal from the beginning, it can be achieved. However, the project was not without its challenges. The project's structure and ambitious goals led to some challenges and missed opportunities. The project raised the issue of whether changes due to the evolution of the design and project team are reasonable and to what extent GSA and the developer can mitigate these changes.
While the team was able to work effectively with local stakeholders, there were some issues that might have benefited from early discussions. For example, an agreement could have been formed with the City of Denver on city-specific issues such as the city light fixtures and street trees up front. Since those fixtures and trees are not compatible with LEED requirements, there might have been a better possibility to explore.
The LEED process also presented a few conflicts including have to address and achieve points for things that did not necessarily apply to the Denver region or the project specifically. For example two years was spent convincing the project team that the green roof required supplemental irrigation due to the harsh arid climate, versus other green roofs installed in temperate climates of the U.S. The project team was initially more focused on not losing the LEED credit and the modeling indicated that the irrigation approach would work. So finally when the green roof was identified as a public good with respect to offering a best management practice for local and regional municipalities it was installed with temporary irrigation and will be studied for its need beyond the plant establishment period.
Additionally, the relationship of a green building to worker well-being was more thoroughly understood as the process unfolded. Members of the team learned to understand the importance of how designing a building and its systems influences employee performance, satisfaction, and health.
Overall most team members commented favorably on the process of working in an integrated team environment. It was new for many and open communication, patience in resolving complex problems, and effective listening were cited as having a positive impact on the goals of the project. Also noted was the fact that the project was very visible for EPA and the federal government and that the team approach offered great value to EPA.
LEED Silver minimum submitted February/March 2007.
None to date
- EPA Region 8 Headquarters: Denver, Colorado, Harvard Legacy Case Study, prepared by Julie Walleisa, Copyright 2006.
- EPA Walks the Walk on New Denver Headquarters, article by Headwaters News, 3-06-07.
- Living in a High-Performance Building: The Story of EPA's Region 8 Headquarters, report by U.S. General Services Administration, June 2013.
- USEPA Region VIII Opens Green Denver Headquarters, article by John Laumer, in Business & Politics, 3-08-07.