When is the last time you walked a job site and looked at the materials that don't end up in the house? If it's been a while, take the time to do it now. An average of 8,000 pounds of waste is produced in the construction of a 2,000-square-foot house, according to various studies and experts.

That's 8,000 pounds you are paying for twice: once when you buy it and then again when you throw it away. Waste disposal costs on average $600 or 0.05 percent of total construction, according to industry estimates. And remember, that doesn't include the original costs or the costs of excess materials “salvaged” by installation crews when there are materials overages.

Most of this excess is easily recycled if there are processors near the site. There have always been good markets for cardboard, aluminum, copper, and other metals. Obviously, hazardous waste needs to be handled carefully and its disposal documented to reduce your liability.

But it would be better to reduce the pile of waste in the first place. One way is to better value engineer the home to optimize materials use. Another is to make sure installers make maximum use of materials.

Just how much savings could be eked out of keeping a better eye on installers? During a study I did for a top 10 builder several years ago, the company executive and I noticed, as we walked through an upscale development, piles of scrap molding at every house under construction. Many of the pieces were long enough to fit several wall sections. An estimate showed the “scrap” was worth between $75 and $250 a house, with an average cost of $120. And that was just for interior molding waste. We didn't look at the costs of any other materials that ended up in the bins.

In an attempt to reduce this cost as well as the cost of the associated waste disposal, liability, and labor, we decided to see if we could pre-fabricate the molding in a distribution warehouse and ship job packs that would fit without cutting. If we did that, then we could also reduce on-site labor time.

Of course, we were naive. We started checking actual wall measurements and compared them to the plan, and we found that the walls were off by an average of 0.85 of an inch, and there were some walls that were off by as much as 8 inches because the concrete pour was off.

The more proven ways to reduce waste are to engineer the structure optimally. Then, make certain that each sub follows the engineering as closely as possible. Finally, work with your suppliers to see how you can reduce order quantities to reduce excess. There is an optimal way to install molding, siding, and many other products to cut down waste. Make sure that your suppliers are using these approaches, and you can save real money while doing the environment a favor. –Michael Hartnett, vice president, Hanley Wood Market Intelligence, mhartnett@hanleywood.com

Average Weight of Construction Waste SOURCE: TOOLBASE SERVICES