The energy capital of the world is poised to grow more energy efficient.

The Houston City Council on Wednesday approved changes to the city’s Residential Energy Conservation Code, increasing by 5 percent efficiency requirements for most newly constructed dwellings.

The move, which supporters say will cut carbon emissions and slash electricity bills, comes as cities across Texas, the nation’s largest energy consumer, are eying building codes as a way to rein in energy use.

“Houston is a hot and humid city, consuming high amounts of energy to temper the indoor climate,” Mayor Annise Parker said in a release. “Anything we can do to ensure homes are more energy efficient will not only help us reduce energy usage, it will also help residents save money.”

This is the third year in a row that Houston has increased its standards, following through on a 2011 goal to make homes 15 percent more energy efficient by 2014.

The changes apply to one- and two-family houses, townhouses and apartments up to three stories high. They will make Houston’s requirements 15 percent stricter than the state's minimum.

Texas last adopted new statewide construction standards for new single-family homes in January of 2012. The state also tightened standards for commercial, industrial and other residences in April 2011. It based those requirements on a model drawn up in 2009 by the International Code Council, a nonprofit that gathers input from experts and public officials across the country.

With its change, Houston joins more than 20 Texas cities in adopting the international group’s 2012 standards, including Austin, College Station and Denison. Environmentalists and some business leaders have called on the state to do the same, saying the move could ease stress on the electric grid as more drastic measures — such as overhauling the wholesale energy market — are considered to ensure Texas can meet its needs.

Buildings account for almost 40 percent of the state’s total energy use and 70 percent of its electricity consumption, according to the State Energy Conservation Office.

Homebuilders, however, worry that too much change too quickly will cause confusion in the industry and add upfront costs to new homes. Some have suggested waiting until the international body releases its 2015 standards, which are still in draft form.