Looking to buy a luxury home with green amenities? The search may not be as easy as you think — even in a region that values alternative energy, sustainable materials and nontoxic environments.

In fact, said David Scott of Colorado Landmark Realtors Inc. in Boulder, the less expensive the home, the more the owners are interested in green amenities, especially when it comes to energy efficiency.

“In the entry-level home market — and keep in mind that an entry level home in Boulder starts at $500,000 — owners are more concerned with monthly savings. For someone buying a home in the $2 million to $3 million range, $500 a month isn’t as significant, so they’re more focused on buying a home with all the features they want — and if they happen to be green, so much the better.

“Everyone is on board with green amenities,” he said, “until they start adding to the cost of the home.”

Scott said he has found that his clients are willing to pay up to an additional 10 per cent for homes with green features. Once the cost of the home starts going beyond that, however, they put on the brakes.

Currently, Scott has a listing at 2002 Alpine Ave. in Boulder that he calls “one of the most luxurious and sustainable homes in America.” Carrying a sale price of nearly $3 million, it boasts several green features: materials using few volatile organic compounds (“low VOC”), sustainable woods, solar hot water, a 9.3 kilowatt photovoltaic electric system, a Viessman radiant heat boiler and a gray water system.

Out of all his listings, he said, it’s the only one that features green, sustainable and energy-efficient amenities.

John Stevens, president of Sopris Homes Inc., a luxury home builder known for breaking ground in energy-efficient residential construction, said the distinctions between those three traits “can be pretty fine. Some people mix green with sustainable with energy efficient.”

Stevens’ customers are very interested in energy-efficient homes, he said. They are highly involved in the early stages of the building process, making decisions and choices that impact the bottom line. For the past several years, Sopris has been conducting audits that quantify the energy efficiency of their homes. On average, a 4,000-square-foot home costs $142 per month for heating and cooling.

Unincorporated Boulder County put an ordinance in place effective Jan. 1 that mandates that new homes of 6,000 square feet or more, including the basement whether finished or unfinished, must be a net-zero energy-efficiency structure. In the past, that could be accomplished by installing large photovoltaic solar arrays on site. Now, however, Xcel Energy has imposed limits to the size of a solar system that can be installed on residences to about 12 to 13 kilowatts. The combination of new building codes and photovoltaic limitations make energy-efficient building practices more important than ever. And none of these considerations includes green or sustainable features as outlined.

Bottom line: Real estate agents and builders say the luxury-home market may not be as green or sustainable as some might hope — at least, not with existing homes. Building from the ground up, however, gives the owner more options to fulfill the desire to live in a green home — however that is defined.