Anew idea is circulating among green building proponents about remodeling: The greenest building is the one that is already built. In other words, an existing home is a great place to start a green building project-in fact, it’s the ultimate recycling project.
An Inconvenient Truth (Al Gore’s Oscar-winning documentary about climate change and the forces bringing this into play) and forward-thinking architects like Ed Mazria are challenging us to move toward a fossil-fuel-free future-to become carbon neutral. When we build and remodel today we must consider moving toward being carbon neutral, and in the relatively benign climate of Santa Barbara, it is achievable. Green building is nothing more than a scientific way of building that saves energy and is healthier for human habitation.
All the energy expended to make your home-your home’s “embodied energy” (the energy needed to mine, manufacture, and transport materials and build your home)-is already literally in your home. Remodeling gives you the opportunity to get the space and function you want and at the same time recycle the “bones” of your home to create energy-efficient space.
According to the Department of Energy (DE), a typical U.S. family spends $1,300 per year on home energy bills, and much of this fossil-fuel energy is wasted. The DE reports, “This is money out of your pocket, and it’s bad news for the environment-electricity generated by fossil fuels for a single home puts more carbon dioxide into the air than two average cars.” (Yet another reason to create a green and energy-efficient remodel and make your next car a fully electric or plug-in hybrid.)
Adding to concerns about the pollution caused by energy generation, scientists suggest we are entering the time of peak oil, which is when the entire planet’s maximum production of fossil fuels is occurring. Ever less fossil fuel equals ever greater energy prices.
One aspect of an energy-conserving home is good insulation and the elimination of heat loss by sealing cracks in the building envelope. Other strategies, like high-performance windows and space and water heating systems, come later, but before we add more energy conserving features we aim for an energy-conserving envelope.
Many homes are not insulated adequately, but insulating an older home is a relatively easy upgrade. For example, where walls have no insulation and wall surfaces will not be removed, recycled cellulose (newsprint) can be “blown” into the cavities between the wall studs (usually 24s) and the vertical wall structural elements.
If interior surfaces are removed, there are a number of green options such as recycled cotton batts or fiberglass. (In the past, fiberglass has not been considered a green material; however, recently some manufacturers have begun making formaldehyde-free fiberglass batts, and some of the fiberglass is recycled and the fiberglass itself is encased in a sheath, making it much more installer-friendly.) Another option is sistering 22s onto existing 24s in exterior walls, which adds to the depth of the insulation cavity, thus increasing the insulation value from R-13 to R-19, which is a significant increase in thermal efficiency.
If an addition is contemplated as well as a remodel, using 26 walls offers greater insulation and therefore greater energy conservation. And if the wall construction module is increased from 16 inches on-center to a material-conserving module of 24 inches on-center there are additional savings due to the use of less material. Using more insulation and less structural material (because the stud and rafter spacing is increased) is a win-win option. And when two stud corners are incorporated in the construction, even more material savings occur.
Because heat rises, insulating the space above our living areas, generally an attic, is of paramount importance to achieve a well-insulated home. The easiest way is to put batt insulation into the attic just above the ceiling.
For greater energy efficiency, consider insulating the rafter cavity, which increases energy efficiency even more. Often heating, ventilation, and air-conditioning (HVAC) ducts run in the attic and if the attic is not insulated, there is great energy loss. Even greater energy efficiency can be achieved by installing a radiant barrier along with the insulation. Radiant heat barriers are very effective when properly installed in conjunction with insulation.
Always attempt to build with nontoxic materials. The materials and systems discussed in this article are generally known to be relatively safe for most people, but any material may be unhealthy for some. If you are a person with chemical or environmental sensitivities (it might be said we all fall into this category, and studies show that babies and youngsters are especially sensitive), research each material before deciding which to use.
While it may seem expensive to convert your house into a green building, less material and energy are used and less time may be involved with remodeling as compared to building new. Yes, some products cost more, but many cost less. And because the building envelope is more energy-efficient, smaller heating systems are required, thus offsetting the cost of high-performance windows, solar features, or other systems oriented to energy efficiency and health. Plus, the benefits are noticeable in comfort, energy efficiency, and a necessary move toward energy self-sufficiency.
Think about the cost of energy in the next five to 10 years; remodeling your home with green objectives today will offset the rapidly increasing cost of imported fossil-fuel energy. Fossil fuel will never again be cheap and will evermore increase in cost. (I venture that fossil fuel-derived energy costs will quadruple or more in the next 10 years.) Installing conservation measures today-like insulation and high-performance windows and appliances-will return ever-increasing financial benefits and lower your environmental footprint.
Roy Prince is a licensed architect in Santa Barbara committed to assisting us to become carbon neutral. Visit AriasPrince.com.