It took a half-dozen workers and one month for Andrew Knight to build what one neighbor appropriately called an “epic treehouse” in his Nauck backyard.

Knight lives just off of S. Glebe Road, and when he bought his house a year ago, he identified the 150-year-old oak tree in his backyard as “perfect for a treehouse.” Some $20,000 later, he has what he terms “a mancave in a tree.”

The inspiration? When the 36-year-old was 6, his parents promised him a treehouse, yet never built it.

“That’s what happens when your parents promise a tree house and don’t deliver,” he said while giving ARLnow.com a tour of the treehouse this week. “When I bought the house a year ago it absolutely was a big part of the decision.”

The platform — built with tree safety in mind by professional tree house constructors, Knight said — is 199 square feet and the house itself is 90 square feet. If the platform were 200 square feet it would have required a building permit, Knight said. The deck is furnished with white wicker chairs and a gas grill, and the inside has a futon, coffee table, small dining set and a lamp, all from IKEA.

Knight, who went to M.I.T. graduate school for nuclear engineering, claims to have held 24 “distinct” jobs so far, including professional blackjack player, high school physics teacher, patent attorney and inventor. He also says he holds 17 patents.

Knight moved to his Arlington house from Sterling and describes his relationship status as “single and looking.”

When the weather warms, Knight plans to host barbecues on the tree house patio and even sleep on the futon. He tried hooking up a space heater via an extension cord to sleep up there recently, but found it was just too cold.

In a sign posted on the fence bordering his property, Knight wrote, “We plan for the treehouse to be beautiful and to make our community more attractive and more interesting. We are happy to give tours to our neighbors after completion.”

Asked whether the treehouse will be an asset or a hinderance in his dating life, Knight was optimistic.

“Who knows?” he said. “Maybe there’s an interesting woman out there who can appreciate it.”