Somerville is touting a two-family home as its first-ever “net-zero” building, according to a city announcement. The home is, owned by Chungha Cha, chief executive of Susterra Partners, a Korean company that specializes in green-building engineering. It has no net energy consumption or carbon emissions, the announcement said. Located at 13 Elmwood St., the house has state-of-the-art solar panels, insulation, and heating and cooling systems. “Net-Zero Energy Buildings are the way the construction industry should be heading, and I commend the developer for their leadership in this area,” said David Lutes, Somerville’s sustainability and environment director. The home is also the first property in Somerville to receive the highest-tier rating from the Environmental Protection Agency’s Energy Star program, the announcement said.