The Bravermans of NBC’s “Parenthood” have a boat in their foyer. So to speak.

Walk onto one of the sprawling soundstages at Universal Studios that are home to the NBC drama, which begins its second season Sept. 21, and the first thing you see is Crosby Braverman’s houseboat, bobbing at the “marina,” although the only actual water in sight is bottled.

Beyond the boat, TV critics visiting the “Parenthood” set last month got to poke around in bedrooms and bathrooms and even peek into fully stocked cabinets and drawers. We chatted with Adam and Kristina (Peter Krause and Monica Potter), who surprised us in their kitchen. Zeek and Camille (Craig Nelson and Bonnie Bedelia) served lemonade. This is one hospitable family.

With a huge cast making up five households and sets taking up parts of four soundstages, the biggest challenge for art director Tim Eckel and set decorator Julianne Getman — beyond the sheer volume of the task — is to lend a distinct personality to each space.

They have succeeded. It’s easy to tell that this is little Max Braverman’s bedroom and that that is the senior Bravermans’ sunporch even if (through the magic of TV) the rooms are closer together than they ought to be. Furnishings and each little tchotchke have been chosen to make each space look both personal and comfortably lived in.

The cast settled in during last spring’s initial run, and beginning the new season felt like coming home, they say. Potter enjoys Kristina’s spacious kitchen, decorated in sleek but homey northern California style, although it makes her feel somehow that she should be a better cook. Bedelia loves to curl up on a swing on Camille’s sunporch.

The favorite spot on the set for some visitors was the houseboat, on which they thought they could comfortably live. But I was most taken with Adam’s shoe factory, with its vintage-look “Welsh Shoes” neon sign and boxes of product samples.

Beyond the soundstages, “Parenthood” also sprawls outside, to a big dining table where all of the Bravermans gather for barbecues and banter. Before we could join them for chicken and burgers, though, everyone sat down to talk about the show. The only absentee: Mae Whitman (Amber), who was attending the premiere of her latest movie, “Scott Pilgrim vs. the World.”

A family atmosphere prevailed as 16 cast members settled into director’s chairs. Little Tyree Brown (Jabbar, Crosby Braverman’s newly discovered son) swung his feet and picked his nose. When his microphone clip came loose, Lauren Graham (his TV aunt, Sarah Braverman) reached down to re-attach it for him.

Asked how he managed such a large cast, executive producer Jason Katims joked, “We’re planning on killing them off, one episode at a time.”

NBC advised waiting to start during November sweeps, he added.

Actually, Katims said, “Writing for the show is an embarrassment of riches, and you can see it right here in front of you. “It’s a big challenge but also what makes the show so wonderful.”

Patience isn’t easy for Dax Shepard, who plays Crosby and watches “Parenthood” every week with his fiancee (Kristin Bell of “Veronica Mars”). (He’s grateful, he said, that he doesn’t have to make her suffer through a terrible show.)

“But every time I’m watching, I’ll see like Mae Whitman in a scene, and I’ll go, ‘I want to be in scenes with Mae Whitman,’” Shepard said. “’She’s so good. When are we going to have a story line?’”

“Everyone on the show, you want to work with at all times.”

Graham sees “Parenthood” growing over time.

“I think it’s complicated, and what I love about our show is that I don’t feel it’s stereotypical,” she said. “Each of these people is getting more and more specific and layered and very real, and there’s a kind of texture that I had not experienced before — it just feels loose and alive and authentic.”

That feeling is what Katims hopes for.

“I like to leave room for improvisation,” he said. “The beauty of doing a television show is that i’s a continuing dialogue. You write something. You put the script out there. Then you see what comes back in the editing room, and I want to be able to respond to that so I don’t have tunnel vision about what the stories are going to be. We definitely have ideas, but I also keep myself open to changing those ideas as we go.”

‘Parenthood’

When: 10 p.m. Tuesdays

Where: NBC

‘Parenthood’

When: 10 p.m. Tuesdays

Where: NBC