In the green homebuilding sector, the construction and demolition phases of the life of a home are regularly neglected, often in favor of focusing all the attention, and marketable money, on building performance. Unfortunately, this neglect of two critical junctures in the building process has negative environmental consequences that are too often unknown to home buyers and left unaddressed by home builders. The truth is, sustainable homes are as much a process as they are a final resulting product – ignoring the two bookends of that process is hardly a winning recipe for a truly sustainable home.
In the green sector, great effort has been made to constantly improve, enhance, and streamline the environmental performance of homes – typically through measures that greatly increase energy efficiency, reducing energy consumption, and generating power onsite. By doing so, green proponents hope to mitigate the massive impact buildings have on both energy use and greenhouse gas emissions. The U.S. Environmental Protection Agency estimates that buildings account for nearly 40 percent of total U.S. energy consumption, sucking up a solid three-fourths of the nation’s electricity in the process.
Furthermore, many would be surprised to find that the residential sector, not the commercial sector, consumes over half of the building sector’s electrical energy. In light of these facts, the design and construction of ever more energy efficient homes is indeed a good idea from an environmental standpoint. However, many green home buyers, builders, and other green sector professionals often fall into the trap of focusing exclusively on the building performance aspect of a project, completely ignoring the equally environmentally important and impactful process of actual building construction, and when the time comes, eventual demolition. Unfortunately, these two separate but related phases, construction and demolition (C&D), that bookend the lifespan of all buildings are often obscured from homebuyers who occupy a dwelling only after its completion, and move on well before its destruction. As a result, sustainable C&D is often overlooked by both consumers and home builders.
Not Very Sustainable
An estimated 170 million tons of construction and demolition-related wastes were generated in 2003. Nearly half came from residential construction and demolition. Observational research has shown that as much as 15 percent of the materials slated for any given project is simply wasted as damaged or unused materials. Americans throw away enough otherwise recyclable steel to rebuild Manhattan, and enough wood to heat 5 million homes for the next two hundred years. Instead, all that raw and processed materials simply end up in the nation’s growing waste streams destined for a landfill somewhere.
That’s not very sustainable.
Yet, the current discussions and dialogues around greening America’s homes typically revolve exclusively around issues of energy efficiency and building performance. After all, despite whatever good intentions pervade the green sector, sometimes money talks louder than the execution of sensible green building practices. And nothing seduces a potential home buyer in the market for an energy efficient abode faster than a shiny array of photovoltaics. If it sells homes, it’s worth investing in.
And sell green homes it does. The National Association of Home Builders (NAHB) expects the green homes market to expand fivefold by 2016, mostly on the growing affordability of sexy cleantech solar panels and other marketable green features. Unfortunately for the green building movement, neglecting a project’s actual construction and demolition process invalidates much of its green credibility.
For starters, many green certification organizations, such as the Leadership in Energy & Environmental Design, and local codes already require some form of waste diversion and management, recycling and salvaging of existing materials on the site, and guidelines for minimizing the environmental impact of demolishing old buildings. More importantly, there is significant value that can be added to a home in both the construction and demolition phases respectively.
A Holistic Process
Integrating the construction and demolition phases into the overall narrative of a green home is critical. On boarding potential homeowners into the process during the construction phase can help them understand what kind of real-world impacts their decisions on paper, such as whether or not to salvage existing materials from the site, can have on the environment. This is known as integrated design. Ecobuilders that involve clients early on, are less beholden to a theoretical bottom line that could hamper a project’s green aspirations.
On the topic of costs, many green C&D strategies present significant cost saving opportunities and are not budget blowers better left to the side. For example, at Native, we recycle scrap wood into mulch for landscaping and other site-specific uses rather than simply disposing of it. Not only is this environmentally a sound practice, it could often be cheaper than moving in a fleet of dump trucks, sorting the wood debris, then shipping out to a landfill far away. Advanced framing techniques are another popular and financially sound way to reduce and divert wastes during the construction phase. Using 24 inch on-center framing, as opposed to 16 inch on-center framing, greatly reduces the amount of raw lumber needed, thus reducing costs while preventing unnecessary waste of the nation’s timber resources. Simple, effective, and often overlooked techniques such as these make the greening of the actual construction process a great exercise in financial prudence as well.
Sustainable homes are as much a process as they are the result of one. How can a builder claim to be green if they ignore this critical phase of the green building process? Yet many do. As homes become ever more energy efficient and outfitted with increasingly advanced systems in the pursuit of performance, it is worth noting that a “green” home is not solely determined by net energy flow. It is the whole lifecycle that matters – from cradle to grave. Construction and demolition are two indispensable fixtures of that story.
What is the story of your home? Remember, building green means building for sustainability from the very beginning to the very end. It also means building to last. Building for quality. And building Native.