SACRAMENTO  (AP) — Driven by a historic drought, California regulators on Friday mandated that lawns and other landscaping on new and renovated homes and buildings across the parched state guzzle less water.

The state Building Standards Commission voted to change development rules to reduce the demand for water. Developers can meet the rules by planting shrubs and bushes instead of grass or installing slow-trickling valves instead of traditional sprinklers.

“You can still see grass, you are just going to see a lot less of it,” said Bob Raymer of the California Building Industry Association, which supported the changes.

The new standards are part of California’s continued targeting of ornamental lawns as water wasters during the worst drought on record. Outdoor irrigation accounts for roughly half of residential water use.

The new standards will take effect Monday for proposed office buildings, schools and hospitals, and on June 15 for housing developments. Officials expect lawns to use about 20 percent less water if developers comply.

Lawns that don’t meet these anti-guzzling rules are prohibited under separate regulations approved earlier this year by the State Water Resources Control Board.

The Building Standards Commission expedited the new rules in response to Gov. Jerry Brown’s executive order for immediate and permanent conservation because of the drought.

Brown had called for a ban on traditional sprinklers for new buildings, but his administration dropped that proposal after industry officials pointed out it may unintentionally ban irrigation systems that reuse water flowing down shower drains and toilets.

The standards approved Friday set a maximum amount of water to maintain new lawns based on a formula. It’s up to developers to figure out how to meet those limits, and to local governments to enforce them.

Brown has ordered communities to cut water use by as much as 36 percent compared to 2013 levels. The state has told those communities to limit how often residents can water their lawns. Some smaller cities have called for an outright ban on new lawns.

Some water districts are offering popular cash rebates to residents who tear out grass and plant drought-tolerant bushes and shrubs.