California’s strict energy rules are often a leading indicator for the rest of the country. The state’s latest energy efficiency standards (Title 24, Part 6) took effect in January, reports Gary Thill in Replacement Contractor. One notable requirement is the use of tankless gas water heaters or water heaters with equivalent performance. “In a short period, consumer demand has pushed the tankless heaters from a fraction of the market to about 50 percent,” Thill writes. “Contractors nationwide can use the tankless water heater guidelines within the California Energy Code to quickly get up to speed on installation and capitalize on this trend.” Other major energy-saving measures include high-performance walls, high-performance attics, and high-performance lighting.