LEED Platinum Office Building
The new two-story office building for the Iowa Utilities Board and the Office of the Consumer Advocate includes open office spaces, private offices, conference and meeting rooms, a break room, record storage, and large hearing/meeting room. The building has been certified LEED Platinum, the highest level, with a projected energy use of 28 kBtu per square foot per year. Geothermal heating and cooling, a daylight-harvesting sunscreen with dimming controls and photovoltaic solar panels were included to reduce energy expenses by more than 60 percent and garner an Energy Star rating of 95 out of 100. A typical office building of this size would use more than three times the energy.
Additional LEED aspects include occupancy sensors, containing and filtering storm water runoff, diverting construction waste from landfills, detailed measurement and verification of energy end use, and use of recycled materials.
In the first year of operation, the building exceeded expectations with significantly lower energy use and higher electricity production from the photovoltaics, resulting in an energy use of 20.5 kBtu per square foot per year, better than the original energy model projections.
The building is used by the IUB/OCA as an education tool for appropriate technologies to reduce energy use and increase efficiency and health in the build environment. Tours are given regularly to the public and interested groups highlighting the features of this high-performance building.
The IUB/OCA building is the first state government agency structure in Iowa to be certified at the LEED Platinum level.
SUSTAINABLE DESIGN ELEMENTS
- Sixty-eight percent energy savings beyond ASHRAE 90.1-2004 in first year of operation
- Captures and infiltrates 100% of stormwater
- Diverts stormwater from 6-acres of adjacent streets for on-site natural treatment
- Thermal mass captures "free heating", modulates temperatures, reducing loads
- Geothermal well field uses the earth’s constant temperature to offset heating and cooling loads
- Use of high performance glass to increase daylighting and reduce lighting power requirements