Their business: producing and selling build-it-yourself, "Klutz-Proof" sukkah kits for celebrating Sukkot, a weeklong holiday that many Jewish people celebrated last week. A sukkah is a temporary outdoor structure inspired by the shelters the Israelites used during their 40-year trek in the desert after leaving Egypt. They are used for meals, entertaining friends and praying during the holidays; some people sleep in them.

This year, the Hermans' 12-year-old business, The Sukkah Project, has sold more than 1,200 kits -- 10 percent to 15 percent more than a year ago -- as well as a host of other products for celebrating the holiday, said Steve Henry Herman.

Raya Cantor Rzeszut, a preschool teacher at the Levite Jewish Community Center in Birmingham, Ala., ordered a kit for her own family as well as a 32-foot-by-32-foot model for the center's youth group four or five years ago. She has been recommending the kits to friends ever since, because she found them easy to construct.

"I tell them, if we can do it, you can do it," she said.

The Sukkah Project -- the legal name of the business is Steve Henry Woodcraft -- has benefited from the surging popularity of Sukkot, which for many years was neglected by all but the most observant Jews.

"More than half our customers are building a sukkah for the first time," Herman said. "It's a wonderful family experience. Building a sukkah is something that parents and children do together."

Their kits comply with the rules laid out in the Talmud about how a sukkah must be built.

"It's not a tiki," Herman said. "It is a holy place."

Herman and his wife. Judith, have no employees, but their children, cousins and other relatives frequently pitch in to help assemble the kits in a nondescript building in Hillsborough. Parts are purchased from outside suppliers.

Kits start at $54 for an 8-by-8 wood-frame sukkah (about $35 worth of lumber must be purchased separately). The most popular of their 22 kits is an 8-by-12 model with a frame made of lightweight steel tubing that costs $330. Their largest sukkah kit -- a 36-by-36 model for synagogues and schools -- costs $2,000.

The Sukkah Project's origins date to 1990. Herman was a medical psychologist at Duke University Medical Center and in his spare time made furniture such as Torah reading tables for synagogues. His rabbi at Beth El Synagogue in Durham asked him to build a sukkah. Before it was even finished, he was fielding a stream of requests from others.

Key to the company's growth, Steve Herman said, is the detailed assembly manuals that include "Klutz Alerts," which warn assemblers of steps where things can go wrong. Steve Herman, who writes "from the perspective of someone who doesn't know which end of the screwdriver to hold," used to revise the manual every year in response to customer inquiries -- but hasn't had to do so lately.

The company's wood-frame kits can be assembled with just a screwdriver; the tubular kits require no tools.

In recent weeks, the Hermans worked up to 18 hours a day along with their daughter, Elissa Poor, 36, in order to fill last-minute orders.

"That's just because it's crunch time in a seasonal business," said Judith Herman. "But as soon as Sukkot is over, I plan to have lots of free time."