On a brisk Brooklyn afternoon, playwright Trish Harnetiaux leaned forward against a retro kitchen table in her apartment in an aluminum-sided row house. A gray, knit-wool cap pinned her blonde curls against her pale cheeks. Without warning, her green eyes turned electric and, like a boxer trash-talking before a fight, she blurted out: “I want to knock the chip off of pretentious theater.”

The 29-year-old Washington State native intends to challenge any misconceptions that theater is “highbrow and boring” and make her art accessible to her sometimes skeptical peers. Her approach is to extend the experience beyond the stage and create an interactive, social atmosphere for the audience.

“Many people of our generation view going to the theater as some sort of cultural penance for watching hours of TV,” she said. “They fail to realize it can be fun.”

Her most recent play, “Straight on Til Morning,” which will move to a Williamsburg theater in January after a run at the Upper West Side’s 78th Street Theatre Lab, is her latest attempt to bring theater to the disinterested masses.

Set in Williamsburg and inspired by J.M. Barrie’s “Peter Pan,” the play features a cadre of soul-searching hipsters in their late 20s.

To entice young theatergoers, as well as enhance the performance, Ms. Harnetiaux transforms the theater venue into Williamsburg itself. The event begins not with the opening curtain, but in the lobby, where the urban, exposed brick design of the set blends easily with the rest of the building. Complimentary Rheingold beer is served to an indie-rock sound track. The audience is free to mingle. It’s a party as much as a play.

“I want to hook you at the door,” Ms. Harnetiaux said as she poured red wine into a highball glass. “I don’t want it to be just theater, but also a concert, a bar, a club, basically an event.”

For her 2003 show “Inside a Bigger Box,” which featured a protagonist obsessed with artwork created entirely on Post-it Notes, Ms. Harnetiaux co-curated a gallery exhibit of similar notepad pieces that was on display in the lobby. For a new musical she is co-writing, which takes a satirical stab at the music industry, Ms. Harnetiaux plans to spread listening booths throughout the building.

“Trish and I want to create theater that is engaging on many different levels” said Jude Domski, Ms. Harnetiaux’s frenetic producing partner and director.

Another way in which Ms. Harnetiaux hopes to reach an audience whose attention spans have been severely depleted is to eliminate intermissions, which she believes kills the drama.

“I’m going to write a play called ‘There Will Be No Intermission,'” Ms. Harnetiaux said. “Because it’s my favorite thing to read when I open the program.”

Although some of her ideas buck convention, her roots in traditional theater run deep. Her father, Bryan Harnetiaux – a successful playwright himself – got her involved with the theater as a child growing up in Spokane, Wash. By contrast, Ms. Harnetiaux initially saw herself under the spotlight as an actress rather than in a behind-the-scenes role. But when she enrolled at the University of Washington at 18, she crossed over after having an epiphany about her acting: “I realized I was terrible.”

In 1999, after working for several years in the Pacific Northwest, Ms. Harnetiaux made the leap to Manhattan.

“I came with four bags and knew one guy from college,” she recalled.

After a rough first six months, during which two grandparents passed away and she got by waiting tables at a chain restaurant, she finally got her break.

Through a mutual friend, she met Eric Nightengale, the artistic director of the 78th Street Theatre Lab, an Upper West Side company renowned for nurturing young talent and encouraging experimental ideas. Desperate for a way in, she took a job as a stage manager – running the light board, preparing snacks for cast and crew. She also got a chance to pass Mr. Nightengale an early draft of “Inside a Bigger Box” and he immediately responded to her talent.

“It’s the way her characters talk and express themselves,” Mr. Nightengale said. “There’s that sense of irony that hides a dreamy romanticism; they’re always looking for something to believe in.”

Seeing a fit, Mr. Nightengale introduced her to Ms. Domski, who was an up-and-coming young director and a fellow University of Washington alumna. They immediately clicked and began work on bringing Ms. Harnetiaux’s script to the stage.

“Trish and Jude are very exciting to work with,” said Michael Colby Jones, who played “Peter” in “Straight on Til Morning.” “Unlike a lot of other writers and directors, they’re genuinely willing to collaborate to help the story grow.”

The pair eventually formed a production company, Morning Line, which often relies on guerrilla tactics to attract a young, contemporary audience – a process Ms. Harnetiaux jokes is the “Howard Dean plan to theater.”

“Trish likes to shake things up,” Mr. Nightengale said. “From the postcard you get in the mail, to the moment you arrive at the show, she takes a very holistic approach and she seems to get off on it.”

Much of Ms. Harnetiaux’s ability to attract new audiences to her shows can be attributed to the positive energy she radiates toward her work in and out of the theater.

“You just have to go out and have fun with it, because it will translate on the page and to the stage,” Ms. Harnetiaux said, waving her hands around wildly. “You can tell when people are not enjoying the process because it bleeds to the cast, the crew, everything.”