The new Hillsdale Library marks the first Multnomah County facility to seek the U.S. Green Building Council’s Leadership in Energy and Environmental Design ( LEED™) certification. With sustainable development becoming the standard for public buildings, this new library offers an environmentally responsible symbol for the community.
The project comes near the end of the Multnomah County Library system’s effort to renovate, repair and construct new facilities to update its 16 branches. The former 6,200 square-foot Hillsdale Library building was deconstructed and an entirely new 13,000 square-foot facility will be built on the same site. Doubling the size of the facility on the property was largely accomplished by placing the parking below grade.
Multnomah County and Thomas Hacker Architects, the project’s designer, brought in Green Building Services to collaborate on ways to achieve the LEED criteria. LEED, currently used as the City of Portland’s standard for sustainable buildings, is a rating system wherein projects are awarded points for meeting pre-determined environmentally responsible criteria
After an assessment of the possibilities, the team set solid and realistic goals for obtaining LEED points. The Hillsdale Library is primed to reach a LEED Silver Award and the team is still considering the potential for a LEED Gold Award. The new building responds to resource efficiencies and sustainable concepts in a number of ways.Materials
One of the first considerations was to minimize the amount of construction waste going into landfills. The Hillsdale project team targeted a goal of salvaging and recycling 90 percent of all materials, which includes the materials of the former deconstructed building.
In terms of LEED, one credit is awarded for diverting 50 percent of materials from landfills and another credit is given for diverting 25 percent more of the construction waste. Because the Hillsdale branch intends to exceed the 75 percent total with its 90 percent construction waste management goal, there is a strong possibility it will receive a third credit – one for innovation.
The materials that go into a building bring a history of environmental impact even before they reach the project. LEED offers credits for recycled materials’ content based on a dollar value standard. If a given material contains 20 percent post-consumer content or 40 percent post-industrial content, 100 percent of the dollar value of that material may be counted. The scale increases so if a material is created from 100 percent post-consumer content, the team is allowed to count the dollar value of the material five times.
By carefully selecting recycled content materials for the Hillsdale Library and calculating their dollar values on the LEED scale against the total dollar value of the project, the library will achieve a 100 percent recycled material value and gain approximately three credits in the process.
The project also incorporates local and regional materials, which minimize environmental impacts by eliminating long-distance transportation and offer support to local suppliers. One credit is available for using 20 percent of locally manufactured materials and, to date, the Hillsdale Library has achieved 46 percent of locally manufactured materials.
LEED also encourages the use of certified wood. Certified wood from Collins Wood will be used for the internally exposed wood deck of the ceiling and building structure.Water
The project will include native vegetation and no irrigation system will be installed. This achieves two credits for water efficient landscaping. Stormwater planters will filter and treat stormwater run-off from the roof. In addition, the loading zone in the back of the building will remain a pervious surface so water can percolate into the soil, which helps to achieve stormwater management credits. Water-saving fixtures will be used throughout the building.Energy
The project used a number of strategies that qualify for LEED points. These include:
- Purchase green power from Portland General Electric.
- Installation of a Direct Digital Control (DDC) system will help obtain a credit for LEED’s measurement and verification. This system controls all the HVAC equipment and will monitor the system at all its control points, (i.e., the motors, fans and variable frequency drives, etc.) providing real-time data for energy use. The system allows comparison of actual energy savings to the predictions of the original energy model.
- Incorporating an underfloor air distribution system. The system is capable of delivering cooling at a higher temperature and at a lower pressure than conventional systems. These factors reduce the work of distribution fans and less energy is used to cool the supply air. With an underfloor air plenum, the air circulation can be distributed by locating registers at any desired position in the floor.
- Going beyond the building commissioning pre-requisite of LEED the Hillsdale branch will gain a credit by involving a commissioning agent in the design process and contracting with the agent to re-commission the building prior to the end of the warranty. The agent ensures that building systems are installed and operating correctly.
- Skylights will bathe the central space of the library in natural light. This open space is designed as the reading room with library services wrapped around it. The use of daylight reduces the amount of electricity needed for lighting and controls will dim the artificial lights as more sunlight enters the space. Lighting generates a great deal of heat and by lowering the continuous use of artificial lights, this strategy reduces the load on the building’s mechanical cooling system.
- A low-E glass double glazed window system to reflect heat and block ultra-violet and infrared light. The windows will have views to the community and natural landscape. Combined with inviting daylight in the space, the views achieve points in LEED’s indoor environmental quality category as well.
Indoor Air Quality (IAQ) for the Hillsdale Library will be enhanced with a carbon dioxide monitoring system, increased ventilation and the use of low volatile organic compounds (VOCs) emitting materials such as paints, sealants and adhesives. A green label carpet will be installed and walk-off mats at the doors will reduce contamination from entering the building.
The underfloor air distribution system will increase air quality by continuously supplying fresh air to the building. Used hot air can be emptied outside the building by a louver tied to the system or recaptured for circulation as required, bringing about further energy savings.
During construction, IAQ management will dictate that ductwork is sealed off to prevent VOCs and other contaminants from later entering the building and eliminate potential humidity, which promotes mold growth. In addition, after construction is completed, the building will be flushed with fresh air for a two-week period.
An Energy Star roof on the building and plant shading of the impervious surfaces on the site will reduce the urban heat island potential of the project. In addition, public transportation access and an electric car charging station will obtain LEED points. These measures meet point criteria for sustainable sites. The Hillsdale Library will also have a car sharing space in the garage, which will count as an innovation credit.
The library will achieve another innovation point as a sustainable building demonstration project for the community. Educational brochures, programs and tours will inform the public and, hopefully, inspire others such as architects, builders and developers to utilize resource-efficient and environmentally responsible measures in their projects and homes.
To learn more about the Hillsdale Library LEED program, contact Ralph DiNola of Green Building Services at (503) 603-1661 or Ralph_dinola@pgn.com.