Builder turns home addition into lab for testing products

Real Estate,Susan Wittman">Tabor Design Build owner John Tabor likes to use his Darnestown, Md., home as a lab of sorts to field-test new and improved products and green technologies before introducing them to clients.

"I'd rather be surprised in my own house than someone else's," said Tabor, whose company is in Rockville.

For a 1,747-square-foot, three-story addition he planned for his home, the main goals were to increase the living space and decrease the utility bills, both by about a third. The addition created a "quiet nook" where he and his wife, Tamara, could retreat while their 12-year-old twins and friends romped in the family room and bounced on the backyard trampolines.

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» Heat & Glo
» Endless Pool
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The addition also expanded the children's bedrooms and added a screened-in porch, an Endless Pool and a hot tub in the basement.

New energy-efficient technologies were included throughout. A refurbished antique mantel with exotic onyx surround in the new living room area caps a Heat & Glo fireplace with insulated doors and outside air inlet. Bamboo flooring, a dual-flush toilet and compact-flourescent and light-emitting-diode lighting help reduce the carbon footprint, as does the superior insulation in the addition and original house.

Thick foam lines the basement's concrete floor, and in the walls, insulating concrete forms and two-by-sixes with structural insulated sheathing are fortified with spray-foam and fiberglass insulation to boost the R-values, which are a measure of thermal resistance. Fiberglass insulation also increases the R-value, while a solar electrical panel sits on the roof and two geothermal systems heat and cool the home.

Richard Lensis, founder of Energy Masters of Virginia in Manassas, did the energy audit on Tabor's home. The amount of insulation determines how high the R-value is, he explained. The more insulation, the higher the resistance to heat transfer from a heated to an unheated space.

"But Tabor did another process that's even more important than massive amounts of insulation," he said. "That's the air sealing process."

Even with a lot of insulation in the attic or walls, if there are holes in the structure for electrical wires, ceiling fixtures or plumbing or HVAC pipes, the air travels through to the attic or outside.

"That's why Tabor applied air sealing and airtight recessed-lighting fixtures. That's probably more important nowadays than the amount of insulation in the attic," Lensis said.

Tabor is carefully testing the newly installed green systems. "They work. The house was an energy hog in a whole neighborhood of energy hogs," he said. He expects for the improvements to pay for themselves in 10 to 15 years if utility prices stay steady.

Like with any experiment, a few unexpected surprises surfaced. Tabor said he was surprised by the comfortable, 70-degree airflow from the new geothermal system. "It eliminates the highs and lows of an inefficient, builder-grade gas furnace and conventional A/C," he said.

But he underestimated the difficulty of installing the insulating concrete forms, which cost roughly double traditional steel forms. For a toasty basement pool room, this is the high-end way to go, he said, but labor and installation cost more than he anticipated.

Likewise, the Endless Pool gives hours of pleasure, but ease of assembly was not as promised. "Some manufacturers' advertising leads you to believe that these products assemble and install themselves, then cut your utility bills in half," he said.

In an earlier test, a "floor-strengthening" plastic membrane caused cracks in his limestone kitchen floor. "Manufacturers do accelerated testing on new products, but it's not the real world," he said.

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