Buying a stock home plan online can be the least expensive and fastest way to obtain a design for a completely new house. Of course, there also are potential drawbacks.

Ben Uyeda, founder and design director at FreeGreen.com. Photo courtesy of FreeGreen.com.

Ben Uyeda, founder and design director at FreeGreen.com. Photo courtesy of FreeGreen.com.

“The best way to get a home is to hire a full-service architect in your area who has a great reputation” and then to have that architect oversee construction, says architect Ben Uyeda. Uyeda may be a surprising source for such a comment: He’s the founder and design director of FreeGreen.com, a startup that offers green stock plans.

On the other hand, Uyeda says, custom architecture is expensive, so it’s difficult to justify on anything by high-end homes. “[Stock] house plans,” he says, “are a great option if you’re building for under $300,000. They are the bargain-basement way to do it.”

A plan designed with a generic site, generic features and generic tastes in mind will almost certainly require some customization. That’s particularly the case if you’re looking for energy efficiency and other sustainable features, and very few of the big online house plan brokers seem to have “green” anywhere on their color spectrum.

Although Uyeda’s company specializes in green homes, even he acknowledges that doesn’t guarantee that “the building’s going to be green, because that doesn’t mean it’s going to be build that way. You can meet with a nutritionist and have a great diet, and then go out and have breakfast that morning that totally blows your plan.”

So Uyeda advises owners in the market for green house plans not to be too impressed by specifications for such expensive features as super-efficient HVAC systems or heavy insulation. Those kinds of things may very well be “value-engineered” out of the project by a budget-conscious owner.

He argues that the real key is to start with a design that takes into account the efficient use of materials and energy — things like modest overall size, short hallways, as few exterior walls as possible, and “good wall sections” (meaning the design of the exterior wall’s cross-section). As a result, he claims, energy models typically find that a FreeGreen.com plan is 30 percent-40 percent more efficient than a standard design.

All this may make it seem like I’m in the tank somehow for FreeGreen.com. I’m not. But Uyeda’s makes some important points: If you fall in love with a conventional site’s stock plan, for example, don’t assume you’ll be able to add a lot of fancy equipment and materials to make it “green” — or at least don’t assume you can do that without spending a lot more money. Before committing to any stock house plan, it would be a good ideas to run it by a green consultant, or an architect or builder with serious green experience, to see if the floor plan and wall sections lend themselves to efficiency.

In a sense, the stock-home-plan route isn’t tailor made for a green custom home — even if the plan itself was tailor-made to be green. That’s because green building typically works best when the owner, designer, builder and even some of the trades plan together. To learn more about the plusses and minuses of other methods, check out my posts on working with custom architects, on design-build firms and comparing a variety of methods.

On the other hand, stock plans that were conceived from the start with sustainability in mind can be thought through very meticulously. And saving money on the initial design could set aside give you room in the budget on customizing the plan or to splurge on great materials.

Here are four websites that offer varying degrees of sustainable features:

• Free Green‘s standard price can’t be beat (I’ll give you a hint: It’s part of the site name). Even unlimited “premium plans” can be downloaded for a $19.95 annual subscription. Instead, the company’s business model involves charging for customization, and in steering owners and builders toward vendors and installers who offer green products or services. “Our goal,” according to the website, “is to give our users house plans which simultaneously provide design and product options that meet or exceed existing third party standards, while giving users choice and options in the realm of cost, style, and environmental commitment. As an example, all of our homes are designed to perform 30% to 50% better than prescriptive building code energy performance. The level of home performance depends on the ‘package’ of products that a user chooses.” That doesn’t mean the company guarantees that if you’ll build one of their designs, you’ll earn, say, LEED for Homes Platinum. But a plan designed with sustainable principles in mind is crucial in making values like energy efficiency, water efficiency, and good indoor air quality easier and less expensive to attain.

Dream Green Homes offers up plans for unconventional construction techniques — even the “conventional” style homes on the site are designed to be built with strawbales, earthbags, insulated concrete forms (ICFs), and other materials. Most of the plans are pretty edgy, and the prices tend to be much lower than on other sites and are likely to be appeal to the truly adventurous. In some cases, local codes don’t recognize unconventional materials and techniques. Before delving too far into such a project, you should check with your local regulators to see what you might need to do to meet code. On the other hand, pricing starts as low as $200 and at least a few of the designers appear to be top-notch architects.

Green Builder House Plans lists “green features” for each of its homes, and gives plan buyers the option to add on an “Energy Star plan package” that the site says will help the house qualify as a U.S. Environmental Protection Agency Energy Star Home. The site is part of a larger family of online, stock plan brokers.

• One of the largest online plan brokers, eplan.com, offers “Green House Plans” and “Energy Saver Plus Plans.” (Go to the advanced search page and click the appropriate category under “Special Collections”). If those plans have many green features, however, it’s difficult to figure out what they are; the site offers no options for modifying plans to improve sustainability.

I’m sure I haven’t caught all the examples. I’m sure I’ve also missed some important pieces of advice. So, if you have something to add — information, insight or a differing opinion — please leave a comment below.