The Idaho Panhandle National Forest Ranger District Office is a one story 13,325 sq ft office building located in Sandpoint, Idaho. The building includes offices for IPNF Rangers and staff, conference rooms, kitchen/breakroom, reception area, file rooms, shower facilities and restrooms. The site is located along US Highway 2 on the east side of downtown Sandpoint. The project has received Gold Certification in the LEED for New Construction v 2.2 program. The building and site have many 'green' features that contributed to LEED Certification including:
- The previously developed site has groves of mature aspen and pine trees that were protected during construction.
- New plants are native or adapted species that will need not need irrigaion after establishment.
- 61,092 square feet of open space is permanently protected from development. This equates to 1.4 acres and is five times the size of the building footprint.
- Disturbed areas were restored with native and adapted species.
- Preferred parking provided for low-emitting fuel-efficient vehicles and carpools.
- Nine secured bicycle spaces and two showers allow staff or visitors to bike to the project.
- Stormwater runoff was reduced from pre-development conditions with vegetated swales and water quality ponds.
- Metal roofing has a special coating that reflects unwanted heat in the summer
- Exterior lighting designed to reduce nighttime light pollution.
- Selection of efficient faucets, lavatories, urinals, shower heads and toilets contribute to a 42% water savings over the Energy Policy Act of 1992.
- Landscape selection of native and adapted plants requires no permanent irrigation needed after establishment of the plants, which means no potable water is used for irrigation. Hand watering will be used for 1-2 seasons until the plants are established.
Energy and Atmosphere
- A full energy model was completed during the design phase showing the proposed building achieves 41% energy cost savings compared to a code-compliant ASHRAE 90.1-2004 building . The savings was achieved primarily through significant improvements in the envelope, daylighting controls and a more advance HVAC system that takes advantage of ground source heating and energy recovery.
- The building’s HVAC system is designed around ground source heat pumps. This will allow the building to reject and extract heat to and from the ground as needed. Only electricity will be required to run the heat pumps and circulate from the building through the ground. There is no natural gas to the building.
- The ground loops have been designed as a horizontal loop field with 6 loops running in parallel out to the field beyond the parking lot where each loop then divides further into seven parallel branches. This design is more economical than drilling vertical wells. The field has been replanted with native grasses and restored to open space after installation of the ground loops is complete.
- The heat pumps are two-stage providing added efficiency and use environmentally-preferable R-410A and R-407C refrigerants.
- Ventilation air is provided directly to each heat pump by an Energy Recovery Ventilation (ERV) Unit located in the mechanical room.
- Domestic hot water heating is also provided by the water-to-water heat pump system. A back-up electric hot water heater is included if for any reason the heat pump supply cannot provide enough hot water.
- Interior lighting includes fluorescent fixtures with energy efficient lamps and ballasts. The lighting control strategy utilizes Wattstopper light energy manager with time clock in conjunction with dimming ballasts, occupancy sensors, photocells, and individual controls for each office.
Materials and Resources:
- The buidling has a comprehensive recycling system for paper, aluminum, plastic, paper and cardboard.
- Over 20% of the materials included in the building contain recycled content. Recycled content materials inlcude rebar, aggregate, metal roof, carpet, drywall, bie racks, insulation, doors and composite wood products.
- Regional materials were sourced for materials such as wood studs, trusses, plywood, particleboard, logs, landscaping, concrete and gravel.
Indoor Environmental Quality
- The building was designed to maximize the benefits of day-lighting and views to the regularly occupied spaces by locating all of the offices and conference rooms on the perimeter of the building. The center of the circulation areas in the two office wings have clerestory cupolas which allow natural day lighting into the core of the building.
- Indoor air quality is monitored by a CO2 sensor in the main conference room which will alarm the building control system if CO2 levels exceed those allowable. The flow through the ERV will also be monitored to ensure proper ventilation air delivery to each zone.
- The individual lighting controls are located within each office and have the capability dimming steps from 100% to 3%. The lighting control system will provide schedule based, occupancy based, and daylight-responsive automated control, as well as multi-level manual control.
Download the USDA Panhandle National Forest Ranger District Office Case Study PDF