HARRISBURG - Gov. Corbett on Monday signed his first bill into law since taking office in January, undoing a requirement that fire sprinkler systems be installed in all new single- or two-unit homes.

"This is a commonsense measure to keep new-home prices within the reach of working families," Corbett said at a bill-signing ceremony in the Capitol.

The bill to eliminate the sprinkler requirement cleared the House and Senate by wide margins this month.

Opponents of the requirement, which took effect in January, said it would drive up housing prices by several thousand dollars. Supporters, including firefighters' groups, said it would save lives.

Builders still have to make known to home buyers that they have an option to install a sprinkler system, Corbett said.

Environmental groups opposed the bill because of a provision that gives an advisory board, controlled by the construction industry, the authority to reject new building codes. They fear that giving the board that power will hurt future energy-conservation efforts.

"It's a real shame they had to throw out the baby with the bathwater," said Janet Milkman, executive director of the Delaware Valley Green Building Council.

She said the Pennsylvania Builders Association could have gotten rid of the sprinkler provision "without affecting every single residential and commercial building project in the state."

The new law requires a two-thirds, or supermajority, vote by the 19-member Uniform Construction Code Review and Advisory Council (RAC) on adopting building-code changes. The group consists of contractors, engineers, architects, building inspectors, and code and other local officials appointed by the governor.

Its job is to make recommendations on changes to the Pennsylvania Construction Code Act or the International Codes, the chief model for state building standards. Under the previous law, codes were adopted if the RAC did not oppose them.

The builders association contends it is not against green building practices but against mandating features that consumers might find too expensive.

Pennsylvania has had a state building code only since 1999, modeled after standards developed by the International Code Council, a membership association dedicated to building safety and fire prevention. The council is expected to issue a comprehensive set of green construction codes next year.

Milkman said she would focus her efforts on ensuring "that when the 2012 ICC updates are up for review, Pennsylvania doesn't get completely left behind."

"Pennsylvania just made it more difficult for us to benefit from the latest practices and technology," she said.

Kevin Shivers, Pennsylvania director of the National Federation of Independent Business, said ending the sprinkler requirement should give a modest boost to the state's housing market.

"The mandate created a disincentive to buy a new home in Pennsylvania," he said. "Repealing it isn't going to create a housing boom, but it will shave thousands of dollars from the cost of new homes, and that should make our market more competitive."

Contact staff writer Amy Worden at aworden@phillynews.com or 717-783-2584.