Two office buildings in Norway are being retrofitted so they will generate more power than they use when the project is completed next year. The three- and four-story buildings, in the town of Sandvika, near Oslo, will generate geothermal and solar energy on site, making the buildings “energy positive,” according to the project’s backers. The retrofit will use a heat-retaining black faÃ§ade, top-quality insulation to reduce energy use by up to 90 percent, and an interior design that will allow air to circulate without fans. “We believe this is the first time in the world that a normal office block is being renovated to such strict standards,” Svein Brandtzaeg, chief executive of Norsk Hydro, one of the project’s partners, told Reuters. According to the UN Environment Programme, the building industry has the greatest potential of any economic sector for large cuts in greenhouse gas emissions.