Green-building and accessibility are the major themes of the 2013 updates to California's construction-related codes, a number of changes to which are set to take effect Jan. 1.

Parts 1 through 6 of Title 24 of the California Code of Regulations (, also known as the California Building Standards Code, were updated in July.

"The biggest, most significant change is in the accessibility regulations," said Rachel Lang, co-owner of Code Source, a Sebastopol-based company that supports a number of local planning and building departments.

The key change is that California's standards for signage, placement of items, ease of movement for wheelchairs, ramps and parking spaces for those with physical challenges now align more closely with federal standards mandated by the Americans With Disabilities Act, or ADA, she noted. That's important because ADA standards are the property owner's or tenant's responsibility to monitor and comply with, with certain exceptions, and not just when a permit or inspection is needed, as with California law.

The California Building Code, part 2 of Title 24, has been modeled after the International Building Code, but the global code's Chapter 11 on accessibility wasn't fully adopted. Rather, the state created Chapter 11a in the state code for accessibility standards for dwellings and Chapter 11b for government, public-access and commercial buildings as well as for subsidized housing.

Because of federal requirements to comply with 2010 ADA standards by spring 2012, California's Division of the State Architect undertook some interim updates to the state's accessibility standards at that time.

"There was a difficulty to determine which was the most stringent between the California and ADA rules," Ms. Lang said. California accessibility rules generally tend to be specific measurements, while ADA rules tend to specify ranges.Energy Code and CalGreen

The 2013 updates to the California Energy Code, which is part 6 of Title 24, take effect in 2014. Construction guidelines for energy efficiency had not been updated since 2008. They are to be consistent with increasing energy efficiency and performance standards for buildings in other standards systems such as the U.S. Green Building Council's Leadership in Environmental and Energy Design.

The updates increase the energy efficiency of homes by 25 percent and of nonresidential structure by 30 percent from the 2008 standards, according to California Lighting Technology Center of the University of California, Davis.

The California Green Building Standards Code in part 11 of Title 24 is commonly known as CalGreen. The 2008 version code took effect in August 2009 as voluntary measures, and the 2010 update became mandatory for new homes and new nonresidential structures and renovations when put into force in January 2011.

A big change in the 2013 update is the scope for CalGreen extends down to nonresidential new and alteration projects as small as 1,000 square feet and $200,000 in value.

On the residential side, the requirement to cut the carpeting in favor of "resilient flooring" such as vinyl or other surfaces that don't trap particulates that degrade indoor air quality expanded to 80 percent of flooring from half the flooring in the 2010 version.