Sustainable Remodel

Next June, when attendees to the Southern Building Show view this remodel, they will see a very strong adaptation of a 1915 brick, Arts and Crafts bungalow.

Tucked beneath the clay tiles of the home’s roofline will be a new second floor that adds 2,200 sq. ft. of living space. On the first floor, a boxy, old-style plan will be replaced with an open, more up-to-date living space. Yet it will retain the graceful pre-War feeling that draws many home buyers to older homes in historic neighborhoods, like Druid Hills, in Atlanta, where this home stands.

Harder to see for those that view the house in June, when the remodel will be completed, will be all of the materials and construction practices that helped make this project an EarthCraft certified remodel. EarthCraft is an environmental designation awarded by the nonprofit Southface Energy Institute in cooperation with the Greater Atlanta Home Builders Association. Southface administers the stringent EarthCraft guidelines in areas of energy efficiency, indoor air quality, durability and several other “sustainable” and “green building” benchmarks.

From the home’s super-tight foam insulation, to its framing practices that eliminate the number of dead air pockets, and the time-consuming efforts to reuse and recycle demolition and construction waste, much of what makes this home an EarthCraft remodel is either invisible or locked in behind the walls. But the effects will be noticeable.

“The home will be very tight,” explains Carl Seville, of Sawhorse Inc., the design/build remodeling firm that is renovating the home. In fact, Seville owns the home and his family will move in after its short run as a show house. “We expect that this home will exceed the limitations on air exhcange, which will make it easier to heat in winter and easier to cool in the summer.”

For Seville, energy efficiency is the prime benefit of sustainable and green remodeling. But the terminology can be a source of confusion. Many people use “sustainable” and “green” interchangeably, but there are some clear differences.

“They both mean that the resluting building will be energy efficient and they both place a premium on the wise use of resources — using fewer materials and recycling materaials,” Seville explains. “But sustainable applies more to the construction techniques and the material savings. Green is a little bit narrower; it also applies to attributes like indoor air quality and durability of materials, among other things. ‘Green’ is a byproduct of ‘sustainable.’ ”

Seville’s remodel project, primarily due to the nature of remodeling itself, with its inherent demolition and rebuilding, tips toward the sustainable side of the equation. Likewise, the processes and methods are as important as, say, the greeness of the materials like biodegradable insulation, etc.

Demolition process
One of the key skills of a remodeler that is interested in green or sustainable practices is a strong knowledge of local individuals and nonprofit agencies that are willing to pick up demolition materials from the jobsite. The two biggest benefits for the environment is the reduced amount of bulky construction waste that ends up in the landfill and the ecological effect of reusing such items as cabinets, appliances and wood. The legwork it takes to have all salvageable materials taken from the jobsite has a definite payback. Seville estimates that this project, with very signifant levels of demolition, will only result in three, 12 cu.-yd. Dumpsters full of trash going to the landfill — about half of the number of Dumpsters usually required to handle the construction waste from a job this size. The other payback comes in the form of tax deductions. Any donations to nonprofit agencies like Habitat for Humanity and others can be written off. Consult your tax advisor regarding the dollar amount that should be deducted. On this job, old cabinets, clean pine wood and other leftover unused building materials are all earmarked for tax-deductible salvage.

Reuse is a time-consuming factor on this and other EarthCraft renovations.

“There is a lot of labor involved to chip the mortar off the bricks,” says Seville, “But we are not simply saving them purely for reuse reasons alone. We would otherwise have had a very difficult time finding new bricks that exactly match to the existing house.”

Much of the reuse on this job is to be facilitated with the aid of a grinding machine similar to the kind that chops tree branches into mulch.

Extra clay tiles from the roof will be ground up and used as a foundation for the new driveway. Any clean wood not salvaged will be ground up and used to protect against soil erosion on parts of this hillside site.

Because drywall was not used in the original construction of the home, very little of it will come out of the home during demolition. But what little there is will be put in the grinder as well. Clean drywall, says Seville, can be ground into a vermiculite and used as a soil additive.

On this job, most of the demolished walls are constructed of lath-and-plaster. The plaster and any painted wood will end up in the Dumpster, but not the lath material. The thin wood laths will either be ground up for erosion-control wood chips, or they will be given to individuals for use as kindling wood.

Framing savings
Construction techniques play a factor in both material savings as well as energy efficiency. On this project Seville and his crews will be careful to eliminate needless headers, particularly those that might have been constructed on nonload-bearing walls.

“This really can save a lot of lumber and you simply don’t need headers in nonload-bearing walls,” says Seville.

Another lumber saving technique is the use of “ladders” and “T-walls.” While reducing the amount of framing lumber required, the resulting walls are more easily insulated, leaving few “cold spots” that are not able to be reached with insulating materials. The same benefits are derived from eliminating a standard framing practice of enclosing corners. An “open corner” framing technique eliminates common sources of “cold spots” and enhances the overall energy efficiency of the project.

When all is said and done to make this remodeling project as tight and as energy efficient as possible, the reduction in air exchange with fresh outside air will be controlled by an air exchange mechanism that works with the HVAC system. The system will be set to change about one-third of the home’s air supply every hour, far less than is the case with an older home like this one says Seville.

To make sure that the home hits this air-exchange benchmark, the home must undergo two tests before it is EarthCraft certified: a blower test of the ambient air in the home and a duct blaster test.

One of the key strengths of the EarthCraft program is the on-site inspections of each project before it can be certified. With the proliferation of green, sustainable and energy-efficient programs that remodelers can take part in, there is some question of authenticity. That is not the case with EarthCraft. With this level of stringency, the EarthCraft designation is even beginning to make an impact on the resale value of certified homes. To date more than 1,500 new construction homes have been certified under the program and about 30 remodeled homes have been EarthCraft certified by Southface.