Massachusetts lawmakers are set to pass a major climate bill that would create new roles for critical state agencies in meeting the goal of net-zero emissions by 2050, Sen. Mike Barrett (D) said Saturday.

“The climate issue has picked up velocity recently … and some key agencies have been slow to pivot,” Barrett said at a webinar hosted by MassEnergize, an organization that helps communities reduce greenhouse gas emissions.

Barrett said that the Massachusetts House of Representatives likely will pass the legislation Wednesday. A Senate vote on the climate bill was delayed last week by Senate Minority Leader Bruce Tarr (R), who requested more time to review the final version of the bill with amendments from Gov. Charlie Baker. (See Vote on Mass. Climate Bill Delayed in Senate.)

The bill rewrites the mission of the Massachusetts Department of Public Utilities (DPU) to align its existing regulatory goals under the overarching job of reducing emissions in the state.

“The job of the DPU needed to be modernized and given a 21st century look,” Barrett said.

The bill also directs Mass Save, a collaborative of Massachusetts’ natural gas and electric utilities, to demonstrate that its efforts to reduce emissions are working. The state program advises residents on how they can lower their utility bills and reduce energy consumption.

The collaborative has not been taking its role in reducing climate change as seriously as it could be, Barrett said.

Powering residential and commercial buildings makes up 27% of emissions in Massachusetts, according to data from the Massachusetts Department of Environmental Protection.

“In the deep plumbing of this bill, we say to Mass Save, ‘Every time you evaluate initiatives — every time you choose to replace a light bulb without talking about heat pumps — we want you to weigh your choices and consider the social value of greenhouse gas emissions,’” Barrett said.

The bill also requires Mass Save to state in its three-year plan how much it will reduce emissions. And the secretary of the Executive Office of Energy and Environmental Affairs will be required to set an emissions reduction goal for Mass Save at the start of every new three-year period.

The DPU will need to report to the Massachusetts legislature whether Mass Save met its goal within 18 months of the conclusion of each three-year period.

The goal of these requirements is to increase transparency between state agencies and the legislature to ensure major state agencies with a high profile “pull in the same direction as the other important actors in the emissions reduction scene,” Barrett said.

The Board of Building Regulations and Standards (BBRS) also faces changes under the climate bill. The agency will have a fundamental role in determining how much new construction in Massachusetts will reflect emissions reductions goals, but the BBRS does not have a full-time staff of professionals. The bill moves the task of designing the next stretch of energy code from BBRS to the Department of Energy Resources, which has a full-time staff of energy experts, Barrett said.

State legislators also will add four green building-conscious members to the BBRS’s board of directors, so the board “has a solid climate-aware majority to guide its fortunes going forward,” Barrett said.