WHEN THE CURTAIN goes up on Act Two of "Enrico IV" at Arena's Kreeger Theater, actor Frank Maraden is carefully constructing a seven-story A-frame structure of playing cards. Halo Wines and Henry Strozier try and carry on a conversation, but they can't help watching out of the corner of their eyes.

It's a fascinating bit of theatrical business, and the audience holds its collective breath, too. But in a moment of frustration, the whole edifice collapses, eliciting a sigh from the crowd.

The architect was assistant property master Lance Pennington; property assistant Deborah Baker assembles it every night during intermission. "She's got it down to less than five minutes," Pennington says. But don't get the idea it was as simple as, well, building a house of cards. Even the simplest effects in the theater have to be carefully thought out.

"It was a problem from day one, when they decided to knock it down every night," says Pennington, who notes that the idea was added to the script by directors Zelda Fichandler and Mel Shapiro. "All the base cards and A-frame cards are stitched together and hinged. The ones {Maraden} adds on are loose cards. It worked great in my room," says Pennington.

But when Pennington attempted it onstage, he discovered there was "a lot of wind in the Kreeger" -- referring not to the actors, of course, but to the air currents that draw drafts toward the stage.

So some of the cards had to be waxed to provide a sticky building surface. Even then, Baker faced another problem: The stage is raked toward the audience. So the bottom layer of cards was cut at an angle so the cards can be assembled straight up.

As for Baker, she says she doesn't really mind building something up just to knock it down: "It's actually nice to have things happen the way they're supposed to happen every night."

New Faces of 1988: As of February 2, the Kennedy Center's long-running farce "Shear Madness" gets a total talent transfusion. Producers/stars Bruce Jordan and Marilyn Abrams are taking some time off and then may rejoin one of the show's two other companies; the new cast includes Washington actors Brigid Cleary, Paul Morella, Michael Chaban and Helen Hedman, and out-of-towners Dan Schiff and Bruce Goldberg.

Hot Seats: Touchstone Theater has until February 1 to clear out of its Arlington space before the wrecking ball hits, and founder/artistic director Michael Murphy says she has a great deal for some lucky theater. Murphy is offering 72 upholstered theater seats free to a good home; she'd like them to go together, if possible, and the only condition is the recipient must arrange for disassembly and removal. There are also some props and tech equipment available; call Murphy at 821-1474.

"Arlington County has said they don't want to lose us," Murphy says, so the theater company may relocate temporarily to the Gunston Arts Center while it looks for a new permanent (or more permanent) home.

Bulletin Board: New York sculptor Phyllis Hammond will design the newly inaugurated Will Award given by the Shakespeare Theater at the Folger to one who has made a major contribution to classical theater in the U.S. The first honoree, who will receive the award April 23 (Shakespeare's birthday), is being chosen by a tony panel that includes Jane Alexander, Zoe Caldwell, Colleen Dewhurst, Gloria Foster, Margot Harley, John Hirsch, Tom Hulce, Derek Jacobi, James Earl Jones, Michael Langham, Christopher Plummer and Michael York . . . Arena Stage company member Casey Biggs will play the title role in Ford's Theatre's upcoming musical adaptation of Sinclair Lewis' "Elmer Gantry." The musical, directed by David Bell, opens February 20; the production marks the 125th anniversary of the opening of Ford's and the 20th anniversary of the restored theater . . . Arena continues its Playlab series with a staged reading of Silas Jones' "The John Doe Variations," a play about self-discovery set in a rest home in Los Angeles. Derek Jones directs, Sunday at 2 p.m. in the Kreeger. Tickets are $5 . . . Broadway bits: Her Royal Highness the Duchess of York, aka Fergie, will make her first trip to New York for the February opening of Andrew Lloyd Webber's "Phantom of the Opera." It's also the royal family's first association with a Broadway production. By the way, Lloyd Webber will have three shows on Broadway at once -- the others are "Cats" and "Starlight Express" . . . And the David Merrick musical "42nd Street" is closing on Broadway after 7 1/2 years and several tap-happy visits to Washington.