It's this year's Pasadena Showcase House of Design for the Arts, bringing in dozens of designers who show off their very best ideas.
"I think at first the house is so large that it's always overwhelming for the public, but they're always impressed, and everyone can take home an idea," said, Donna Gotch, benefit chair of the showcase.
Some 35,000 visitors will come through the living room, taking note of everything from paint color to paintings.
"The ceiling between the beams, that has all been specially painted for Showcase in a custom color for this space," said Gotch.
Showcase has raised more than $18 million over its 48 years for the L.A. Philharmonic and youth programs. It's one of the oldest and biggest house-and-garden tours in the country.
This year, there is the main house, a cottage, a writers retreat and a greenhouse. The name of the house is Casa de las Puertas, or "House of the Doors." Unlike Showcase houses in the past, they've left many of the doors on so you can see how the house got its name.
The kitchen is a study in contrasts, from a handmade blue French stove, to a modern microwave oven that opens like a drawer.
"Showcase really is kind of one of those places where you want to do as much as you possibly can. We try to balance that out in a tasteful way," said designer Greg Parker.
There are counters made of quartzite stone and a backsplash with ribbons of hammered nickel. There are features like the old-fashioned sleeping porch with still-working Murphy beds. But the bed in the master bedroom suite is fit for a king -- or queen.
Some rooms, like the lady's study, were dark and dreary. They're now light and bright.
"You want them to come in and just go, 'Wow!' and have that moment, and not sort of think about the before-and-after," said designer Kristi Nelson. "Just, 'This is a beautiful room and I want to have this room.'"
It takes a long time to make over a mansion. The owners agree to move out for six months at their expense, but the results are well worth the additional rent.
Showcase tickets cost between $30-$40 and can be ordered by mail or purchased online at pasadenashowcase.org, or call (714) 442-3872.
The showcase is open for a total of 25 days, from April 15 through May 13 on Saturday, Sunday and Tuesday from 9 a.m. to 5 p.m.; and Wednesday, Thursday and Friday from 9 a.m. to 9 p.m.