For the first time last year, the majority of new homes built in Seattle were built “green,” according to the local homebuilders association. Portland home builders are also going for healthy, energy-efficient construction in a big way.

“Green” building entails things like added insulation, non-toxic or recycled building materials and EnergyStar appliances. In Washington state, the most common voluntary standard is called Built Green. It was created by the Master Builders Association of King and Snohomish Counties in 1999.

Portland-based Earth Advantage promotes a very similar standard in Oregon.

Built Green Program Manager Leah Missik said certifications crossed a milestone in the past year in the city of Seattle when the majority — 52 percent — of new homes and townhomes earned a “green” label.

“Part of the reason for our success in Seattle is that the city offers incentives for builders to go through our program,” Missik said. “For example, they can get their permit faster and then also Seattle City Light will give a rebate to builders building certain types of Built Green homes because of their electricity efficiency.”

Missik said green building certifications are much lower in places without builder incentives or utility rebates.

Energy Trust of Oregon distributes incentives to builders specifically for achieving high degrees of energy-efficiency in the parts of Oregon that are served by private utilities. An Energy Trust spokeswoman said 38 percent of all new home construction in its territory last year qualified for a rating that earned the builder a rebate. That percentage was up significantly from 2015.

Builders have to pay to enroll in the Built Green program in Washington state and to hire a third-party verifier for each project seeking certification. The increase in a home’s sticker price varies depending on which features or energy efficiency strategies the builder chooses to achieve certification.

Missik said a recent analysis she worked on found that electrically heated homes constructed in 2014 to the mid-level Built Green standard saved $406 on average on their annual electric bills compared to non-certified homes in Seattle. Healthier indoor air, a lower carbon footprint and increased home value are other reasons to consider.

“I would argue that if people are looking at different homes, and all other things are more or less equal, they would want to go for the home that is a green home,” Missik said in an interview Tuesday. “Although it’s hard to quantify, I would argue that there is an advantage to having the certification.”

Built Green certification is geared toward residential construction. Earth Advantage mostly does residential with some small commercial buildings.

Larger commercial and public buildings that strive for “green” cred often use a different standard called LEED, short for Leadership in Energy & Environmental Design. Washington state was ranked among the top ten states for LEED-certified square footage per capita in 2016. Massachusetts, Colorado and Illinois led off the list. Oregon did not reach the top 10.