An effort to adopt a new more energy efficient building code has received mixed support from Duxbury selectmen.

Selectmen voted 2 to 1 Monday to endorse Article 46, an annual Town Meeting warrant article sponsored by the Alternative Energy Committee that would adopt a state building code called the “stretch code.” The stretch code is an optional appendix to the Massachusetts building energy code that requires new construction and renovations for both commercial and residential buildings to be 15 to 20 percent more energy efficient.

“It promotes better energy efficiency in town,” said Alternative Energy Committee chairman Jim Goldenberg. “Most builders build to it anyway.”

For residential buildings, the stretch code mandates that homes larger than 3,000 square feet achieve a Home Energy Rating System (HERS) rating of 65 or fewer. A home with this rating is about 35% more efficient than a similarly sized home built to base code levels. Houses smaller than 3,000 square feet must score 70 or better.

To achieve this energy efficiency, a house will be required to have more insulation in the walls, floors and basement and more efficient heating and cooling systems, as well as more efficient lighting.

“After rebates, the stretch code adds about $2,000 to the cost of building a new 3,000 square foot house,” Goldenberg said, adding that that money is usually recouped in lower energy costs after three to four years. 

Selectmen Chairman Shawn Dahlen owns a home building company and said he encountered the stretch code when building a home in Kingston for a relative. He said it added $1,500 to the cost of a 1,600 square foot house. Much of the cost was due to the required on-demand hot water heater that cost $1,000 more than a regular water heater. 

“It’s a kick in the pants to do the right thing,” said Dahlen.

Dahlen said the stretch code mainly applies to new construction and total rehabs, and will not affect existing houses if they are not included in a renovation/alteration. He said he knows this could be a concern to Duxbury residents who live in centuries-old historic homes.

Dahlen and Selectman Ted Flynn voted to endorse the stretch code article. Selectmen Chris Donato was not in favor of it.

“I agree with the idea of the stretch code, but I’d rather leave it up to residents,” said Donato. “It could affect the costs and I do not want a resident to take on further costs if they can’t afford it.”

Goldenberg said the state’s energy building code is due to become more stringent and equal stretch code requirements next January. Then the stretch code will again set the energy efficiency bar higher by 15 percent.