California regulators in May mandated that all newly built single family houses have solar panels as part of the state’s aggressive push to combat climate change. The California Energy Commission voted 5-0 to approve the measure, which also applies to multifamily buildings of three stories and fewer. The mandate is set to take effect in 2020 and does not need the approval of the Legislature. The requirement is expected to save consumers money in the long run through reduced utility bills, but also makes a new house more expensive to purchase at a time when many families already struggle to purchase a mortgage. In addition to the solar mandate, the Commission approved new insulation and air filter requirements for newly built homes. In all, the new residential requirements are expected to raise construction costs for a single family house an average of $9,500, but save $19,000 in reduced utility bills over a 30-year period, according to the Energy Commission.