Here's the dirt on mudrooms: They've come a long way. From humble beginnings as back rooms or porches where farmers dumped muddy clothes or boots, the mudroom has morphed into a sophisticated, multifunctional space that belies its name.

Homeowners gussy them up with high-end finishes, custom built-ins, upgraded floors and lighting, even occasional antiques. Whether they double as potting sheds, hobby rooms, kids' airlocks or elegant back foyers to welcome guests, 21st-century mudrooms increasingly are merging function and style.

"Everybody wants a dressed-up mudroom because a lot of people enter the house through the back," said Daniel Sachs, principal of architecture firm Sachs Lindores in New York.

When planning a mudroom, consider these options:
• Built-in charging station for mobile devices
• Tough, impermeable flooring like slate or dark porcelain tile; a washable area rug
• Floor drain
• Dog sink or shower
• Drinking fountain for thirsty kids
An armoire or dresser
Message center
Radiant-heated floors

At a Rhode Island estate, quarter-sawn oak paneling and antique French limestone floors evoke a stately British manor. An early map of New England caps an antique table Sachs discovered in London. An 1880 English sconce and three copies flicker on the wall. "The main entrance is exquisite, but in the end almost everybody comes through that back door near the parking area," Sachs said.

Mudrooms designed with young children in mind require a different approach, said Bethesda architect Greg Wiedemann.

For a family who parks on a driveway in front of their Bethesda home, he designed a mudroom-office with a side entry and sunny windows facing the front porch. Hooks, cubbyholes, drawers and banquettes with storage organize clothes, shoes, sports equipment and office supplies. The rugged floor is gray slate.

"Mudrooms have become one of the most important spaces in the functioning of the home," Wiedemann said. When planning a mudroom, first determine its use, storage needs, continuity with the home's style, and available space, he added.

Maine interior designer Linda Banks didn't have space for an extra room, but she needed more storage. Her solution was to aesthetically unite the mudroom with her kitchen and sitting room. Her simple yet romantic mudroom is inspired by summers on Ile de Re, a French island. A vestibule off the back door features whimsically mismatched hooks on beadboard, storage baskets and a weathered bench for removing shoes.

A repurposed turn-of-the-century window invites light to filter into the sitting room. "Architectural salvage is one of my trademarks," she said. The "wallpaper" is oversize copies of an Ile de Re map, and the painted floor is a soft checkerboard of back-sanded white and pale gray paint; corner dots are tiny squares of silver leaf. "I wanted it to look almost transparent," she said.

It's worth it to carve out space for this crucial transition room between indoors and out from a kitchen relocated during renovations or an attached garage, Wiedemann said. Even a space as small as 5 by 8 feet provides extra storage, he added.