To reduce a building's environmental impact, reduce the amount of energy it uses. But significant impacts also occur in the production and disposal of building materials.
September 01, 2009
A version of this article appears in the September/October 2009 issue of Home Energy Magazine.
I remember the moment I started thinking seriously about the solid-waste practices of Snug Planet, my home performance company. I was tidying up our workshop at the end of the week and noticed a piece of polyisocyanurate board in the trash bin. It was L-shaped, about 2 feet on a side, big enough to block a couple of joist bays or a crawlspace vent. I realized that if that piece of foam went to the dump, I would have paid for it several times: the initial purchase price, the crew time spent loading and unloading it, and finally the tipping fee at the dump. And yet it wouldn’t have generated any revenue. Just as bad, that piece of foam took energy and raw materials to produce, yet it didn’t save any energy. I took the board out of the trash bin and put it on the rack with the whole sheets.
As home performance contractors, we know that the most important way to reduce a building’s environmental impact is to reduce the amount of energy it uses. But significant impacts also occur in the production and disposal of building materials. Nationally, construction and demolition (C&D) waste accounts for about a quarter of the material in landfills. Case studies by EPA and others have shown that the volume of C&D waste can be significantly reduced by efficient layout, reuse of salvageable materials, job site recycling, and alternative methods of disposal, such as on-site mulching of waste wood. Leadership in Energy and Environmental Design (LEED) standards and National Association of Home Builders (NAHB) Model Green Home guidelines include sections on C&D waste management. Many states and municipalities have also launched initiatives aimed at reducing C&D waste. These programs emphasize that a well thought-out waste management plan can save on both material costs and disposal fees. As I began to investigate Snug Planet’s waste stream, I wondered if lessons from new construction—and whole-building deconstruction—could be applied to a home performance business. Is it possible to divert a significant amount of waste from the landfill without adding prohibitive costs? Could a well-thought-out waste reduction plan actually increase profitability?
|The presence of a dumpster makes it too easy to throw things away without regard to the true costs of this convenience.|
The waste stream from home performance work differs from the general C&D waste stream in a couple important ways. In new construction, the most common waste products are Sheetrock, wood, and cardboard; in a typical project these make up 60%–80% of waste by weight or volume. In demolition/deconstruction projects, bricks and other masonry may make up a large fraction of the waste, especially on a weight basis. In our home performance contracting, we find that the type and quantity of waste varies greatly from one project to another; on any particular job we may be dealing with empty cellulose bags, old windows and doors, cardboard, or bags of degraded fiberglass. Also, because we usually work in occupied houses, processing and sorting of waste takes place back at the shop.
Nevertheless, many of the ideas about reducing job site waste discussed in the new-construction, remodeling, and deconstruction literature can be adapted to home performance. I followed the general steps recommended by the booklet Waste Management and Recovery: A Field Guide for Residential Remodelers, published by the NAHB Research Center. First, I inventoried my waste stream and associated costs. Next, I looked at options for redirecting this waste. Finally, I developed a written action plan. While greening our operation by reducing waste was an important goal, I was particularly interested in solutions that saved money or were at least cost neutral. I also wanted to develop a system that was robust enough to persist through changes in staff and workload.
The Auditor Gets Audited
I called on the Tompkins County Recycling and Solid Waste Division, which manages the county transfer station. The Division has created a “ReBusiness Partners” program, which seeks to assist local businesses in reducing waste, increasing recycling, and purchasing recycled products. The Division conducted a solid waste audit on our operations. They met with our crew and office staff, poked through our trash pile, and prepared written recommendations. They also provided us with some very handy compact recycling bins for our office and provided us with some free exposure by listing us on their Web site as a ReBusiness Partner. The audit provided us with a good start; it was particularly helpful in improving our office recycling systems and in getting our team excited about the possibilities for waste reduction.
However, we found that we needed to look harder for ways to deal with construction-specific waste, which forms the majority of our waste stream. Through research, contacts in our community, and trial and error, we’ve discovered waste reduction, re-use, and recycling options for many of the common items we encounter.
The key to waste reduction is to use lumber and sheet goods efficiently. Efficient design and framing techniques can dramatically reduce waste when our scope of work involves new construction. Optimal value engineering (OVE) techniques—such as design based on 24-inch modules, 19.2-inch or 24-inch stud spacing, single top plates, and two-stud corners—can reduce the amount of framing lumber used and waste wood generated. OVE techniques also improve energy performance by reducing thermal bridging.
Time spent on planning efficient layouts can reduce material waste even in energy retrofits that do not involve framing work. We often use sheet goods such as polyisocyanurate board to insulate crawlspace walls and to enclose open cavities in attic slopes and kneewalls. In order to satisfy the New York State Building Code, which requires that exposed foam insulation be covered with a thermal barrier, we use Dow Thermax board. At around $0.90 per square foot for 1-inch board, it is a pricey material. We encourage our crew chiefs to plan installations carefully to minimize difficult-to-use small scraps and narrow strips. We also prefer to cut the board on a table saw rather than by hand. In addition to reducing waste and speeding installation time, the use of the table saw yields tighter seams and a neater, more finished appearance.
Inevitably, we do end up with some small scraps of Thermax board. However, home performance projects can utilize scraps that builders and remodelers would not consider worth saving. The key to using these small pieces effectively is a simple, robust system that keeps the materials organized and within easy reach. Our waste management plan calls for saving scraps larger than 8 inches x 16 inches. We store scraps in contractor grade garbage bags, which we bring along on air sealing jobs.
We also keep Sheetrock and plywood scraps larger than about 16 inches square for patches, attic hatches, and enclosing recessed lights. We use a similar approach for trim wood. We encourage crew chiefs to plan their purchases and cuts to minimize waste. Trim pieces down to about 24 inches are stored in bins in our shop and are used for small projects like attic hatches.
Demolition and remodeling projects can yield a wide range of reusable building materials, including brick, framing and trim wood, plumbing fixtures, windows, doors, and cabinetry. These materials may be reused on-site, sold directly, or donated to nonprofit salvage and reuse centers. Reduced tipping fees and tax deductions can offset the extra labor associated with deconstruction and processing of the materials. In addition to saving resources and landfill space, reuse can add interesting elements to a project.
We have found some limited opportunities for reuse. While our local nonprofit architectural salvage group no longer accepts most old single-pane windows, we have installed a few in our unheated workshop, and employees have taken some home to build cold frames for use in gardens, or to install in unheated outbuildings. We do save and reuse old bronze sash locks, which are often of excellent quality. Planking or plywood pulled up to air seal an attic floor is sometimes removed at the customer’s request and saved for reuse.
On the HVAC side, steel gas piping can be rethreaded if necessary and reused. Round ductwork and other sheet-metal fittings can often be cleaned and reused.
It is important to note that in home performance work, many materials removed from houses are too degraded (rodent-infested fiberglass), too toxic (trim covered with lead-based paint), or too inefficient (old appliances) to be recycled.
In Tompkins County, cardboard and office paper can be recycled at no cost, either curbside or at the transfer station, as can beverage cans and bottles. We also generate a small but steady stream of scrap metal, which embodies large amounts of energy but is easily recyclable. Our metal waste includes aluminum storm windows, dull hole saws and saw blades, and nails and screws. We have a scrap metal bin in our shop, with a bucket for smaller items. Because the quantity of metal is small, we haven’t found it worthwhile to sell the scrap, but we can drop it off at no charge for recycling at our county transfer station.
Our HVAC subcontractors generate a much larger quantity of metal; for a typical boiler replacement, they may haul away a couple of hundred pounds of cast iron and steel, plus a smaller amount of copper and bronze. Even though the price of scrap metals has dropped dramatically since 2008, it is still high enough to justify a separate trip to a scrap dealer.
Mercury thermostats, which can contain hundreds of times as much mercury as a compact fluorescent light bulb, require special treatment under New York law. Upstate Energy Solutions returns these to their equipment supplier for reprocessing. The owner, Paul Myers, was the person who brought the mercury issue to my attention; he shares our commitment to recycling and proper handling of toxics. We are currently working to incorporate our waste management guidelines into agreements with our electrical and carpentry subs.
In addition to recycling cardboard, cans and bottles, and metal, we compost food scraps, coffee grounds, and cellulose packing peanuts. Clean, untreated wood too small to be used for carpentry projects is burned in our wood stove, which heats our home office.
We found very early in the process that we needed the physical infrastructure to store usable scrap and to sort recyclable from nonrecyclable waste. We needed to make the system convenient for everyone to use. We divided the wall of our workshop, just to the left of the main doors, into three bins: one each for garbage, cardboard, and metal recycling. Immediately to the right of the doors are storage racks for scrap Sheetrock and plywood, bins for trim wood, and bags for foam board scraps. This setup facilitates rapid sorting, as materials are unloaded from the vans. It also places usable scrap materials within easy reach, reducing the temptation to use whole pieces.
The system is simple and intuitive and was developed with the input of the crew. It is part of the day one orientation for new crew members, who do much of the van loading and cleanup. The system enjoys a high level of participation and buy-in.
Prior to initiating our waste management plan, we experimented with having a dumpster at our shop. Our hope was that the time saved on dump runs would offset the delivery and rental costs of the dumpster. However, we’ve decided we are better off without it. After implementing our waste management plan, we’ve found that we only need to make a trip to the transfer station about every other week. Therefore, the crew travel time costs less than the rental fees for the dumpster. In addition, the presence of a dumpster makes it too easy to throw things away without regard to the true costs of this convenience.
A well thought-out waste management plan can save money in reduced materials costs and tipping fees. Our tipping fees now average less than $100 per month, or less than 0.2% of our total operating expenses. In addition, we are making better use of materials, and having a well-organized assortment of scraps has more than once saved us a trip to the store. Although there was an initial investment in planning and infrastructure, it costs very little to maintain the system. The small increase in labor (probably on the order of a few minutes a week) is easily offset by improved materials efficiency and reduced disposal costs.
Many of our customers are environmentally conscious and are avid recyclers and composters themselves. Communicating our waste reduction strategy lets them know that we share their values. I have noticed that it seems easier for customers to accept replacing an old furnace or boiler that’s still chugging along if they know it will be recycled. Therefore, our standard proposal language now reads, “Remove and recycle existing equipment.”
Since we implemented our plan, I’ve noticed that usable foam scraps have disappeared from our trash pile. This means that they’re going into people’s attics and basements, where they belong.
Jon Harrod owns Snug Planet LLC, a home performance contracting company based in Ithaca, New York.
>> For more information:
Waste Management and Recovery: A Field Guide for Residential Remodelers. Upper Marlboro, MD NAHB Research Center. Available online at www.epa.gov.waste/conserve/rrr/imr/cdm/pubs/remguide.pdf.
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