Two buildings at Hubbell Realty Co.’s Riverpoint Office Park have received Energy Star certification from the U.S. Environmental Protection Agency, ranking them among the top 15 percent of buildings in the country and improving Des Moines’ ranking to No. 5 for midsize cities, according to a release. From 2016 to 2017, Hubbell saved 16,689 kilowatts and $1,014 in energy costs at the two properties, which measure 40,080 square feet and 36,071 square feet. Hubbell launched a sustainability plan in the last year that includes prairie burns, planting of native landscaping in communities, and other efforts to focus on economic and environmentally friendly initiatives, according to the release. According to the EPA, Energy Star certified buildings use an average of 35 percent less energy and fewer greenhouse gas emissions.