Written by: Diana A. Horvat, AIA, IIDA, LEED AP & Dave Bloom, AIA, LEED AP of Envision Design
The World Wildlife Fund (WWF) is one of the world’s leading conservation organizations; it works in 100 countries and has more than 5 million members globally.
In 2007, WWF asked Envision Design to gather a team of consultants for a sustainability charette focused on improving the overall sustainability and operational footprint of the building. The project was called “Beyond Platinum” because WWF was seeking innovative thinking on a long-term sustainability strategy, not simply meeting the requirements of the LEED rating system. The consultant team included Dan Nall from Flack and Kurtz in New York, Bill Browning of Terrapin Bright Green, Chris Pyke now with USGBC, formerly with CTG Energetics, Inc., and Roger Courtenay of EDAW.
The charette was convened in two stages. The first stage focused on big picture, broad ideas. The second was a “what it could look like” review.
After several review sessions with WWF, it was decided to pursue two tracks. The first was to improve the efficiency of its existing HQ building in Washington, DC, and also its operation. The LEED EB version 2 program was selected for this process.
The second was to create a model for WWF’s future office space, for which the LEED-CI version 3 was selected.
The following article addresses the two projects independently; however, the truly sustainable nature of the projects intertwines the goals of both projects in day to day operations and use.
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World Wildlife Fund wanted to create a prototype office space for their staff that would embrace the WWF brand, demonstrate applied sustainable practices, and repurpose and underutilized space in their building.
The building was constructed in the 1980’s under a PUD requiring retail space to be provided in the building. Over the years, the nature of the neighborhood changed and a retail presence in an English basement situation was not viable, despite numerous tenants making an attempt to create a viable business in the mostly hotel populated neighborhood.
After years of persistence, WWF was able to get the PUD modified. It decided to use this English basement space for its staff, demonstrating that it could be a vibrant, light-filled office space. Its location in the building also provided the staff access to previously underutilized patio areas.
The program called for a mix of open and private offices and conference rooms. The floor plan was carefully organized to maximize the use of available daylight and to create an open collaborative work environment. Sustainable finishes, material, lighting, millwork, and furniture have been specified throughout. Modular workstations and demountable partitions provide flexibility and allow WWF to reconfigure the space as their needs change.
The process engaged WWF staff members in the review of plans, mock-ups, and materials.
“It was with great enjoyment that we watched the WWF staff’s enthusiasm for the project build and emerge as the layers of old construction were stripped and a new light filled space was created. Now, a previously undesirable and underutilized space is one of the most preferred office areas in the WWF headquarters.”
Located in the West End neighborhood of Washington DC, WWF is ideally situated to take advantage of access to public transportation and the many amenities available in an urban area. Additionally, WWF provides all their employees to access to bike storage areas and changing rooms. As the owner of their building, WWF has applied for and earned LEED EB version 2 Platinum certification.
Water Use Reduction
Water usage for occupant plumbing fixtures (faucets, showers, toilets, and urinals) has been reduced by over 40% through the installation of low flow fixtures, dual flush toilets, and pint flush urinals. These measures have contributed to reducing the occupant water usage from 129 kGal/yr to 75 kGal/yr.
The mechanical system, lighting system and office equipment were selected and designed to use the minimum amount of energy while maintaining a comfortable indoor environment for the occupants. For the energy the space does use from the grid, 100% is offset with renewable energy credits (25% form local wind, and 75% from national wind).
HVAC & Associated Energy Efficiency Measures
Two water-cooled VAV air-handling units serve the space. Ventilation air is distributed to each unit from an outside airshaft and ducted to an inline fan that then distributes the air to each air-handling unit. The air-handling units are cooled by an existing cooling tower loop. Waterside economizers in the air-handling units are used to provide free cooling. Conditioned air is distributed to VAV boxes throughout the space. Exterior zones include electric reheat coils at the VAV boxes. To verify the design and construction of the mechanical system, the commissioning agent reviewed the design documents and inspected the system after installation. The mechanical system was awarded 10 points under EA credit 1.3 Optimized Energy Performance HVAC.
Lighting & Associated Energy Efficiency Measures
The lighting is a combination of high efficient fluorescent fixtures and LED fixtures. Since the space is partially underground, great care was taken to balance the desire to optimize the energy performance of the lighting system while providing a comfortable lighting level for the occupants that compensates for the reduced amount of daylight. To help reduce the actual electricity used to light the space, daylight sensors have been installed for all fixtures within 15 of any window and occupancy sensors have been install in all the private offices and conference rooms.
Throughout the space, materials and furniture where specified to maximize the use of recycled and regional materials and FSC certified wood. WWF has an aggressive building wide recycling policy that results in the diversion of over 90% of the building trash from the landfill. In keeping with this policy, over 95% of construction waste was recycled.
WWF is not only committed to the preservation of the natural environment but to the health and wellbeing of their employees as well. To this end, the air quality during and after construction was carefully protected. Low-emitting materials where used throughout the space and the amount of fresh air delivered to the space has been increased.
As a prototype space for WWF, is was important to incorporate a means of tracking the energy usage of the space. To that end, the space has been connected to the base building energy dashboard system. This interactive display is centrally located in the building’s main lobby and is accessible to occupants and visitors. Through the dashboard, people can examine how much energy the space and the building as a whole uses. This energy can be displayed as total energy or sub-divided into plug loads, HVAC loads and lighting loads. The dashboard also display the amount of water used in the building. The dashboard system is part of a large program to education occupants and visitors on the benefits on green buildings.
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In further support of their mission, WWF also decided to pursue, and earned, LEED EB version 2 Platinum certification for their headquarters. WWF is the only LEED EB version 2 Platinum building in Washington, DC.Ãƒâ€š It is also one of only three non-profit-owned Platinum buildings in the world.
The building, originally a parking garage, was converted to an office building in the mid-eighties. WWF purchased the building in the late 1990’s. The building has over 265,000 gross sqft and is 8 stories above ground with 2 levels of parking below ground. WWF occupies approximately half the building; multiple tenants occupy the rest.
The challenges for this project included upgrading the existing building systems that were over 25 years old in a manner that maximized the environmental benefit while being cost effective.
In addition, as a multi-tenant building, it was important to get buy in from all the tenants. To reach the project goals, each tenant had to contribute by providing documentation for the LEED submission and following new building policies designed to reduce the building’s environmental footprint. A team was assembled to address these challenges and to develop an integrated solution. This team included the Project Manager, Architect, MEP Engineers, Commissioning Agent, Building Management, WWF, and numerous contractors.
To manage the complexities of a project this size, the standard LEED checklist was expanded to track information on pre-performance period tasks, performance period tasks, the status of the LEED template, cost implications, the responsible team member, and due dates. This document was updated on a bi-weekly basic and distributed to the team.
HVAC System and Energy Efficiency Improvements
To help determine the most cost-effective way to improve the energy efficiency of the building, the commissioning agent surveyed the existing building systems and developed a list of improvements. The project team then judged the proposed improvements on their energy efficiency impact, contribution to LEED credits, and cost implication. With this information, the team was able to make informed decisions on which improvements to pursue.
The building HVAC system is a water-cooled, self-contained air-conditioning system. There are two such units per floor. The air from the units is distributed to VAV air terminals throughout the space. Heating is via electric reheat coils in selected VAV terminals and perimeter electric baseboard units. Condenser water for the typical air-conditioning unit is routed through cooling towers on the roof.
Improvements to this system included upgrades to the air-handling units to take advantage of free cooling in the winter, testing and rebalancing the entire building, installing temperature, CO2, and humidity monitors throughout the building.
Furthermore, new policies were enacted to provide staff education, a schedule for system maintenance, and system monitoring protocols that will help enable the building to continue to perform at this high level into the future. The efficiency measures outlined above have contributed to a 32% reduction in the energy usage intensity of the building.
Energy Intensity for the Site [kBtu/Ft2/yr]: 66 (National Average: 98)
The remaining building energy usage is 100% offset with renewable energy credits (RECs), specifically 25% from local wind and 75% from national wind.
The building has achieved an Energy Star Rating of 86 out of 100. A rating of 75 is needed to quality as Energy Star. When compared to the average office building of the same size, these savings translate into a reduction of the following pollutants:
- CO2: 4,021,987 lbs/yr
- Methane 173 lbs/yr
- Nitrous Oxide: 34 lbs/yr
- Nitrogen Oxide: 6,042 lbs/yr
Water Use Reductions
Water usage for occupant plumbing fixtures (faucets, showers, toilets, and urinals) have been reduced by over 20% through the installation of low flow faucets and shower heads, dual flush toilets, and pint flush urinals. Water for exterior landscaping has been reduced by over 95% through the use of local and drought tolerant planting and the implementation of a green landscaping policy.
Furthermore, a 25,000 sqft extensive green roof (representing 75% of the total roof area) was installed. This constitues the largest green roof on a commercial building in DC and the 3rd largest overall.
The combination of various sedum species, specially formulated soil, and a retention mat contribute to a 50% reduction in the amount of stormwater runoff leaving the site (677,000 gallons/year). By reducing runoff, the green roof decreases the amount of contaminants that find their way to local waterways. Reduced runoff also helps decrease erosion and downstream flooding be decreasing the amount of water delivered to waterways during storm events. The green roof also contributed to reducing the heat island effect by creating a surface that is more reflective then a standard roof
To help educate occupants and visitors about the benefits of green buildings, WWF has developed an educational program that includes tours of the building and green roof, and an interactive energy dashboard system. This display is centrally located in the building’s main lobby and is also accessible through the Internet. The dashboard allows people to examine how much energy the building uses and to compare it to regional data.
As WWF renovates its existing offices, each space will be connected to the dashboard. People will then be able to compare the energy performance of each space to one another. To date, WWF has renovated and connected two separate office suites to the dashboard.