PROVIDENCE — With less than five years on the clock before Rhode Island’s next major climate deadline, state officials are just beginning to cobble together a strategy for the second-biggest source of greenhouse gas emissions in the state.

The Executive Climate Change Coordinating Council (EC4), an entity made up of 13 state agencies, is expected to release its final report on how to lower building emissions on Feb. 15.

Most residents probably don’t think of their home or favorite local business as a major source of greenhouse gas emissions, but added up together, residential and commercial buildings account for 29.5% of all emissions produced in Rhode Island, second only to the transportation sector. Industrial buildings and processes added another 5.7%.

These emissions come from the combustion of fossil fuels — natural gas, heating oil, propane, and others — for space heating, water heating, air conditioning, and cooking. Industrial sites may also produce emissions from manufacturing or industrial processes.

While the state has a plan to phase out gas-powered cars, and is mandating that retail electricity sold in Rhode Island come from only renewable sources by 2033, state leaders have lacked a serious plan to lower building emissions, or even a way to track them building by building.

At a listening session on the EC4’s building decarbonization plan, attended by some 100 people on Monday, officials from the Office of Energy Resources (OER) acknowledged the gap.

“There’s a lot of work left to be done,” said Jack Green, a U.S. Department of Energy Fellow at OER. “The report will provide some insight into the role that building energy benchmarking and performance standards could play in achieving [emission reduction] goals.”

Green said the final report from the EC4 focuses on buildings that are more than 25,000 square feet, some of the largest buildings in the state. While they only account for 35% of all structures in southern New England, they represent 75% of building emissions. In Rhode Island emissions from buildings over 25,000 square feet make up 20% of emissions, and 10% of all buildings statewide.

“It makes sense to target because you can address a much larger fraction of the emissions with a comparatively smaller fraction of buildings,” Green said.

In the report, OER estimates the state has at least 2,320 buildings that fall under the largest building definition, and 81% of those buildings fall into one of four categories: industrial, multi-family, office, or retail.

About half of the largest buildings use electricity as their primary energy source, with another 31% using natural gas, 8% using oil, and 7% using steam — half of the buildings owned by the state are served by steam, according to OER.

Monday’s listening session was one of the final parts in the EC4’s building decarbonization report before it’s submitted to lawmakers next month ahead of its Feb. 15 deadline. The study was commissioned by legislators last year in a joint resolution, who passed on creating a benchmarking program in state law before getting the state’s climate and energy experts to weigh in on how it could be done.

The EC4 is accepting public comments on the report draft until 4 pm. Friday, Jan. 31.

The EC4 isn’t the only government entity that’s been looking at large building emissions. Last year Providence became the first municipality in Rhode Island to start its own energy benchmarking program for its largest buildings, after the City Council approved a new ordinance creating the program. The city has its own climate goals of reaching net-zero emissions by 2050, and the new program is meant to steer building emissions in the right direction. Buildings account for 70% of the city’s carbon footprint.

Last month the city’s Office of Sustainability released a report on the first year of the program, listing all the largest publicly owned buildings greater than 10,000 square feet. (The benchmarking ordinance gradually phases in private owners of large buildings over the next few years. This year will require buildings larger than 50,000 square feet to report starting on May 15, with buildings greater than 20,000 square feet starting next year.)

The report found that the city’s K-12 school buildings accounted for 77.1% of the square footage owned by the city (the report lists 64 buildings), and 74.3% of the energy used to operate the city’s buildings.

When compared against the national median provided by the U.S. Department of Energy, the Providence schools compare favorably, although the city report notes that “older buildings without central air-conditioning and ventilation systems perform better in this type of comparison, they are not as healthy and comfortable to occupy.”

Going forward, the city expects the emissions stemming from its school buildings will shrink as older school buildings are replaced or renovated according to the new, low energy intensity standards from the New England Coalition for High Performance Schools.

In its report, the city also notes that most benchmarking programs nationwide only have around 14% compliance in the early years, with many of the issues arising from a lack of data on buildings and the energy used. Rhode Island Energy won’t have a permanent solution to energy tracking until after the May 15 deadline for private owners, according to the report.

It’s the same issue facing state officials as they attempt to outline a statewide benchmarking plan. The estimates in the EC4 report were, with the help from the Division of Statewide Planning, derived from commercial real estate transactions from 2020.

“There’s no comprehensive database currently available that details all the large buildings that exist statewide,” Green said. “Creating such a database would be costly and time intensive.”

He said launching a statewide program would take at least 18 months to complete, including time for the related state agencies to promulgate rules and regulations about the program. Following its launch, energy reporting would be slowly phased in over the intervening years, before energy standards taking effect in year 10 of the program. The owner of any building that did not meet the energy standards would be fined.

The good news? Implementing such a program might not need that much in the way of new resources or personnel, according to Green. OER would require one new full-time position to implement the program, and Gov. Dan McKee included one position in his budget request released in mid-January.

“We know that more emissions reductions are required to meet our 2030 Act on Climate target,” Green said. “But we also know that benchmarking and performance standards take time and resources to achieve success. Balancing these priorities will be key to achieving a fast yet effective rollout.”