Editor’s Note: This is the third of three articles on practical, cost-effective, green building techniques. To read the previous article, click here.
A few months ago, we set out to identify a few sustainable building techniques that actually save builders’ budgets.
We came up with fifteen.
So what is the point—that it costs less to build green? Certainly not. A sustainably-built house will cost between 2 and 6 percent more than a traditionally-built house (but far less than the 15 percent builders assume, from a recent survey*).
But not every practice will cost more. Some, in fact, cost less, and that is the point. Green building is a continuum and exploring some of these techniques is a good place to start.
There are, of course, good reasons to build sustainably other than saving money. It’s simply more efficient, in terms of materials and resources. It makes business sense to change the perception in some quarters of builders and developers as despoilers of the planet. And yes, building greener does help save the planet.
Plus, the market is shifting, as you’ll see in our first cost-cutting idea. Homeowners are now looking for sustainable (or “high-performance”) homes, which makes this category the brightest segment of an industry that could stand to look on the bright side.
1. Build Smaller Houses
A 2004 nationwide National Association of Homebuilders (NAHB) survey reported that 67 percent of homeowners would prefer a smaller house with high quality products and amenities over a larger house with fewer amenities. That figure was up from 41 percent in 2000.
Angie’s list, a home-improvement reference service, surveyed 7,700 members and found that 67 percent felt their home was just the right size—and that 47 percent lived in a home under 2,000 square feet.
So why are we still building McMansions, that cost more to heat and cool, clean, maintain—and pay taxes on? Many homeowners, intimidated by the idea of resale, buy homes that don’t suit them. Yet 77 million aging boomers are becoming empty-nesters and are ready to downsize. The concept of what makes a resellable property is downsizing along with that market.
The commanding paradigm is moving away from “bigger is better,” and toward the idea of building a house for the three bears—one that’s just right-sized. Consider this: Sarah Susanka’s books (the first was The Not So Big House in 1998) that began the downsized housing trend have sold over a million copies.
There’s a growing interest in smaller developments that emphasize connections between inhabitants. Cottage housing places more, but smaller, homes on a lot surrounding a common or community garden. Putting a smaller home in that kind of context positions it for greater buyer interest and justifies greater density.
How much can you save? That depends on what level of amenities you want to include, but if you are able to quote per-square-foot costs to homeowners, you could use those same numbers to calculate your own savings for a house with a smaller footprint.
2. Reduce, Reuse, Recycle
There are a number of environmental advantages to using recycled building materials. Building a 2,000 square foot home generates just under a half a ton of waste. Recycling materials from an existing home, recycling agency or salvage yard saves costly trips to the landfill.
Recycling also promotes local re-use, which means shorter hauls and less use of fossil fuels in the shipping of materials. It could also save significant money if you know where to look.
Habitat for Humanity’s ReStores are retail outlets that sell used and surplus building materials at far less than you’re spending now. Bookmark all the sites listed in the sidebar, and become a salvage-yard browser. It makes you the stand-out builder in your market.
One of the best sites—www.build.recycle.net, offers sections for used brick and block, lumber and wood, plumbing materials and fixtures, doors and windows, electrical and lighting items, heating and cooling equipment and “other used building materials,” in addition to a section on used construction equipment.
Granted, recycling (or “freecycling” if you find the right source) may be best suited to smaller builders, but you’d be surprised at what you can find in large quantities on the open market.
3. Bend the Sewer Lines
Most gravity sewer lines in a development are installed in a straight line. At every change in direction, codes mandate a manhole. The online resource, www.toolbase.org, suggests that a curved sewer alignment can save up to 19 percent of the sewer installation budget by eliminating some of those expensive manholes—up to $1,500 each.
It’s important to note that they’re not appropriate everywhere. While curvilinear sewer lines are code in cities like Phoenix, AZ, Chicago, IL, and Los Angeles, CA, they’re most appropriate in new suburban developments with a curved street design. For example, Chicago’s tight grid pattern and a code-mandated distance between manholes make it difficult to realize any savings there.
But, where they do work, curved sewer lines also make it easier to avoid other utilities since they all follow street alignment. And because the design follows topographic contours, the grade is uniform. Cleanouts can be installed to provide access for inspection and cleaning.
Another sewer savings: Using one common sanitary sewer lateral to service two or more dwellings saves labor, equipment and materials costs. Cost savings will equal the total cost of the eliminated main line taps plus their respective service laterals. Typical savings range from $250 to $350 for every eliminated sewer connection.
4. Gang water service
Water lines can also be ganged to serve several dwellings. A single 1-inch tap from the main water line can be used for both single-family detached houses and row houses. For single-family detached dwellings, a cross-fitting between the houses served allows a service lateral to extend from the 1-inch tap across the property line to the house (with ¾-inch leads to individual water meters).
For single-family attached dwellings, a common 2- or 4-inch service lateral extends in front of the buildings, with ¾-inch laterals installed between each two townhouses, and a cross-fitting connection at the individual unit. Using a master meter for the building saves even more money, but is not a requirement.
One builder in the Houston, TX, area saved $200 to $330 for every ¾-inch service tap and â…-inch meter installation eliminated. Master meters tend to be more expensive individually, but save money by eliminating individual meters. To figure cost savings, simply add up the eliminated individual laterals and their main service taps.
You can also save up to $.87 per linear foot by installing plastic tubing—either polyethylene or polybutylene—instead of expensive copper or galvanized iron. Unlike metal pipe, plastic won’t corrode in corrosive soils, but care should be taken to install it below the frost line, since frozen lines cannot be thawed electrically.
5. Dig a Common Utility Trench
The practice of ganging electric, telephone and cable TV (and even natural gas) in a common trench is an obvious money-saver. The rates developers pay electric utility companies are often based on the difference between pole-mounted and underground service installation costs—so it makes sense that putting other services in that trench would reduce these charges.
There are other builder advantages to joint trenching. It allows developers to space units closer together, using more of the land because of smaller utility easements. This also requires less clearing of the natural landscape, which saves clearing and grubbing costs. And if the utilities can be coordinated—or are already doing so, as in San Diego, CA—it reduces the construction cycle.
The last point is an important one. Utilities vary in their zeal to cooperate with each other. But where they do, the savings can be significant. The typical cost of excavation plus backfill for a 1-foot by 2-foot trench is $5 to $7.50 per square foot. According to Toolbase, our source for this story (and the two previous tips), “If costs are shared equally, savings would be $3.33 to $5.00 per foot for three utilities and $2.50 to $3.75 per foot for two utilities in a common trench.”
* – Energy Efficiency in Buildings Summary Report, World Business Council on Sustainable Development, August 2007
Jeff Binder is senior editor of www.greenbuildingblocks.com, a website devoted to sustainable building techniques.
Construction Business Owner, March 2008