Green Living
The Greenest House in the City
Three years of hard-core planning led to this Weatherby Lake home leaving a light footprint on the planet.
When Shauna Zahner set out to build a new home for herself and her husband, Mike, she hit the mark on a number of major trends popping up in home design. As a designer and sales representative for Stitt Energy Systems, a company that specializes in the design and building of super energy-efficient homes, Shauna knows how to build a ‘green’ home inside and out. But she also included elements of the “Not-So-Big” phenomenon, universal design, working from home and multigenerational living.

Engaged in so many philosophies, her home is arguably one of the most ‘thoughtful’ in the city. But it’s her dedication to improving the planet through better building practices that makes her home so unique. “Being green doesn’t just mean adding one thing, like a heat pump; it’s changing your whole thought process, your whole approach to design,” Shauna explains.

First, the Zahners looked for an infill lot in an older neighborhood that was relatively close to the city and amenities, faced south, had plenty of trees and would be wide enough for them to build a home focused on single-level living. (It took them a year and a half to find.) Once they purchased their property at Weatherby Lake, they designed the home to be small (compared to many new homes) and narrow. At 2,340 square feet, the floor plan sprawls 80 feet across the lot and only 30 feet deep.

The master suite is on the east end, with the garage (located at the back) and the foyer separating it from the main living space, which includes a great room, kitchen, eating area, laundry room and office. The upstairs fits in studio space and two additional bedrooms for Shauna’s mother, who stays with the Zahners part of the year.

By orienting the house to face south, Shauna can take advantage of the sun to heat the home in winter, keeping indoor temperatures around 73-74 degrees, using no energy. “It’s great because nothing runs during the day,” she touts. Called passive-solar design, this orientation allows the sun from south-facing windows to warm the home during the winter when the sun is low and the trees are bare; wide eaves on the outside of the home prevent too much solar heat gain during the summer when the sun is hot and high. Low-e, argon gas-filled windows help regulate heat by allowing it in during the winter and reflecting it away during summer; they also add a layer of insulation and protect furnishings from fading.

Radiant heat, a series of tubes with hot water running through them underneath concrete floors, kicks on when necessary. Emanating warmth directly to your feet, it can make you feel warm all over even with lower thermostat temperatures. The Zahners also use a 16 SEER Trane heat pump to do both heating and cooling. A cast iron wood stove is capable of heating the entire house; a concrete board behind it acts as a heat shield.

“Since you can’t see most of the energy features we incorporate, many people don’t want to pay for them,” Shauna says. “But there is a growing market of people who are educating themselves.”

Energy Star appliances and compact fluorescent light bulbs (CFLs), which are widely talked about as green features, are a given in this home. “I think there’s only one light fixture in here that doesn’t have a CFL,” Shauna notes.

A number of inclusions in the Zahner home helps keep what energy they do expend from seeping out. The largest of them is the insulated concrete forms (ICFs), which are made up of two pieces of Styrofoam held together by recycled plastic fittings that insulate the concrete that is poured in them for the foundation walls. The ICFs completely surround and insulate the exterior edge of the concrete grade slab, which would  normally be exposed and lose heat. The north-facing garage (which houses a 2001 Prius) is insulated on three sides, plus the garage door is insulated.

Shauna used soy-based expandable spray foam rather than fiberglass insulation in the above-grade walls and attic spaces, which does a better job of filling in cracks and crevices in the home’s envelope, keeping drafts out and  everyone inside comfortable. She also insulated the ductwork, used a raised heel truss at the ceiling to have room to spray extra insulation at the top plate, and implemented an effective method of venting attic space for summer cooling called an ice-house roof.

“Forty-eight percent of energy in the country goes to heating and cooling our buildings, and we are losing a lot of it,” Shauna says. “We can’t continue like this. If we’re not doing our part, we’re not being responsible.”

But because their house is so tight and energy-efficient, the Zahners have to bring in fresh air mechanically through an energy recovery ventilator. That is the key to reducing stale air and worsening reactions to contaminants and off-gassing chemicals trapped in the home, as well as removing moisture build-up, which contributes to mold growth.

Another heating element the Zahners have is a solar water heater. A single panel atop the roof captures enough energy to heat 80 gallons of water when the sun shines. A backup electric coil picks up the slack on cloudy days. The couple saves water with low-flow faucets.

While they wouldn’t reuse water for drinking or bathing, they do collect rain water for their landscaping needs, capturing runoff from their roof in rain barrels and in their rain garden, a shallow impression with native plants that grow deep roots and absorb more water. They kept most of the mature trees and their natural undergrowth intact, while the rest of the yard is mulched so that there is no need to mow, side-stepping a huge source of pollution almost entirely. They even create their own fertilizer by mulching leaves and composting kitchen waste.

The Zahners save and reuse other items, too, like antiques, which ground the open interior spaces. The house showcases 35 years worth of collections and heirlooms. “Everything in here is very personal,” Shauna says.

She admits they and their home are not 100 percent green — as she does love hot showers, and Mike had to have a small patch of grass in the side yard that he could mow — but it’s near as good as it gets. 

RESOURCES
Designer: Stitt Energy Systems
Builder: GEMS Construction 
Interior Stained Concrete Floors: Canyon Stone
Windows: Alside
Cabinetry: What Not Woods
Patio and Rain Garden: J&B Lawn & Landscape
Heating & Air: Kjelshus Energy
Spray Foam: Beyond Insulation
Energy Star Rating: Hathmore Technologies