If you've ever seen the demolition of a house, it's an impressive thing, what with shattering windows, twisting plumbing, crushing timbers, and the big truck that takes everything to the dump.

After 1992's Hurricane Iniki on Kaua'i, there were proposals to try to save useful construction products — windows, doors, toilets, timbers — so they could be used again, both to reduce the load on the landfill and to reduce rebuilding costs. Nothing much came of that, in part because it wasn't an easy process to pull out house components without damage.

It would have been a lot easier if those pieces had been designed to be recycled. The group West Coast Green, in a news release, said that building materials now account for 60 percent of the flow of materials in the United States after food and fuel. And 33 percent of the solid-waste stream — much of which goes to to the dump — is from demolition of buildings.

Many efforts to promote "green" housing, like the Leadership in Energy and Environmental Design, or LEED, certification process, have focused on things like frugal use of environmentally benign materials and energy-efficient design. Builders across Hawai'i, whether they seek LEED certification or not, are increasingly using energy-efficient building techniques and designs.

Now the U.S. Environmental Protection Agency, along with GreenBuildingBlocks .com, the Building Materials Reuse Association, the American Institute of Architects and West Coast Green, is holding a competition to go the next step — to look beyond the home or office's immediate use and think about the functionality of its materials after the existing building has lost its usefulness.

The idea is to think of building components in the long term. You wouldn't throw away the painting on the wall just because you're moving out. Here, you'd think about the wall itself in the same way.

Why demolish a wall that can be used perfectly well in another house? A properly designed wall potentially could be unbolted, moved to a new location and bolted to other walls in a new configuration. Same with other building components. Design for disassembly, design for deconstruction or lifecycle design — whatever you call it — saves landfill space, saves energy, saves new materials and presumably can reduce housing costs.

To learn more about the competition, see www.lifecyclebuilding.org. The competition is seeking ideas for whole buildings, components, or a tool or practice.

If you have a question or concern about the Hawaiian environment, drop a note to Jan TenBruggencate at P.O. Box 524, Lihu'e, HI 96766 or jant@honoluluadvertiser.com. Or call him at (808) 245-3074.