Green building is mainstream. A 2012 McGraw-Hill Home Builders and Remodelers Study found that 34% of remodelers expected to be doing mostly green work by 2016. But what exactly do they mean by “green?”
Images the term conjures up range from bamboo flooring and composting toilets to $40,000 solar arrays. But while a green home could include any of these, none define it. What a green home must have are the same things most people look for in a car: low maintenance and high fuel economy. Fortunately, delivering these is a matter of good, basic construction practices.
Going green is also getting less expensive. The McGraw-Hill study also found an average cost of just 7% more than conventional construction, compared with 11% six years ago. “You can build very efficient homes at very low cost,” says Steve Easley, a California-based consultant who teaches builders across the country how to go green. Material choices do matter, but how they’re installed is just as important, if not more so. In fact, a smart dealer might consider a seminar for builder customers on these topics.
Keep It Simple
While you need not sacrifice curb appeal for lower cost, Easley points out that a simple floor plan is inherently resource-efficient and relatively easy to build and maintain. The extra costs—and potential headaches—for a complex footprint start with the foundation and continue to the ridge. A complex foundation means a complex floor plan and an equally complex roof plan with lots of hips, valleys, and other intersections.
No one expects architectural complexity to go away, but the fact remains that a simple home with a straight gable will use less materials (lower construction costs) and will be less prone to leaks or other moisture problems (lower maintenance costs).
Keep It Dry
One of Easley’s favorite sayings is: “The greenest home you can build is one you don’t have to rebuild.” The National Green Building Standard apparently agrees, since it includes a section on durability.
When a home starts falling apart, the culprit is usually water damage caused by poor drainage, flashing, or water management. You expect most builders not to make these mistakes. But Easley, who make his living investigating building problems, says sloppy design and detailing are rampant.
Avoid horizontal valleys. These water traps include places where side-by-side gables meet at the eave or where a roof slopes into a chimney or wall. If they can’t be avoided, use crickets and saddles to direct water into gutters and downspouts.
Use kick-out diverter flashing. The point where a roof gutter meets a wall is another trouble spot. Kick-out diverter flashing minimizes problems by directing water into the gutters and away from siding.
Build overhangs. A Canadian study found 80% of multifamily homes with moisture in the walls had no roof overhang. That deficiency made water more likely to flow down the siding and into the wall. Unfortunately, small or nonexistent overhangs are common on all home types.
Limit and seal penetrations. Every roof and wall penetration (plumb-ing vent, electrical penetration, etc.) is a potential leak. Use butyl-based self-adhered flashings to seal penetrations, and carefully inspect those flashings before installing the siding.
Properly detail building wrap. When (not if) water gets behind the home’s siding, you need a system of properly integrated flashing and building wrap to direct it back outside before it can work its way into the structure. It sounds like a no-brainer, but Easley still sees a lot of homes with poor detailing.
Pay attention to site drainage. Surface water that seeps into the ground near the house can quickly become an interior moisture problem. Site the house high enough above grade so that water can easily drain away from the foundation. If necessary, install a foundation drainage system.
Keep It Tight
The most oft-cited reason for building green is the promise of energy savings. While most builders try to get there with more insulation and better heating and cooling equipment, many still fall short.
For instance, today’s building codes mandate higher R-values, and equipment efficiencies have doubled. Unfortunately, the average home still isn’t performing much better than 10 to 15 years ago, Easley says. His main culprit: sloppy workmanship.
More insulation is great, but there’s often greater savings in paying attention to how that insulation is detailed, especially when using batts. The key is to make sure there are no gaps, the insulation is fully lofted, and it fills the entire cavity.
Another important step is air sealing. Problem areas include around windows, doors, attic hatches, and other penetrations. Recessed light fixtures can also be quite drafty, so avoid using them in ceilings under unconditioned attics. Where that’s unavoidable, specially made covers can be slipped over the fixture from above and installed with sealant to prevent drafts. If you want to learn more about improving energy performance, free web and video training is available. Just go to eneregyvideos.com.
The only way to accurately gauge air-sealing effectiveness is to test it— which is why the latest energy codes require blower door tests. Independent companies nationwide now offer home performance diagnostics.
Builders also should try to choose green materials and products, but the big savings are in design and detailing, and builders who take it seriously will reap the benefits. “Most builders I talk with who have made this transition are very happy,” Easley says. “Their homes are more energy-efficient and their customers more comfortable. And they tend to be more profitable.”