The new building codes include updates to building ventilation and lighting standards.
It would be the first such mandate nationwide and California's latest step to aggressively curb greenhouse gas emissions.
"We think it's another example of California policy preceding what will happen in other markets", Tom Werner, chief executive of San Jose-based solar company SunPower, said in an interview ahead of the decision.
Adding solar panels would boost construction costs by $9,500 for a single-family home but save owners about $19,000 in energy and other expenses over 30 years, the Energy Commission estimated. In California's coastal communities, at least, research has found that the sharp rise in housing costs is mostly driven by rising land costs, said Issi Romem, chief economist at BuildZoom, a permit and contractor data analysis website. Instead of delivering electricity from centralized fossil fuel power plants, the primary goal of California's energy grid is now to move electricity among various distributed solar and wind power generators.
The new requirement will take place starting in 2020.
The move still needs backing from the state's building standards commission.More news: Three reasons the Golden State Warriors dominated the NOP in game four
California averages about 80,000 new homes a year, with about 15,000 now including solar installations.
Some critics, though, question the wisdom of the transition to solar at a time when California is struggling with a dire housing crisis and skyrocketing housing costs.
If approved as expected, the vote by the five-member California Energy Commission will trigger a huge increase in solar installations. But as per the expert's view, this extra investment done while building new homes will be recovered as there will be saving on energy bills for a lifetime.
California has pursued a wide-ranging list of policies aimed at reducing greenhouse gas emissions.
Effectively integrating a growing supply of intermittent solar and wind energy will require adding far more storage, transmission, and smart grid systems.
The mandate, which will change the building code for residential buildings up to three stories high, aims to increase the amount of solar energy used in the state.
In terms of building costs, the Commission says it will add just under ten thousand dollars to up-front costs, but will save nineteen thousand dollars over a 30-year period.
"Alex Steffen, who writes about sustainability and urban planning, said the state's biggest climate challenge is the fact that Californians drive so much".