One of the hottest trends in home design is bringing the kitchen outdoors to make grilling more than just for burgers. This model home in Oakland Township, Michigan, features an outdoor kitchen area with a Wolf oven with warming drawers and a Sub-Zero mini fridge.

DETROIT — The unofficial grilling season is under way, and one of the hottest trends is bringing the kitchen outdoors, literally.

Once thought only practical in warmer climates, outdoor kitchens in Michigan are heating up.

Makers of high-end grills and outdoor appliances — distributors, landscape companies and home builders — have seen this trend grow.

Built-in grills that spew out more than 50,000 BTUs and cost $7,000 and up. Outdoor-ready pizza ovens for $12,000. Dishwashers that cost $4,000. Outdoor kitchens, even in Michigan, are trendy and part of the planning stages of some new construction.

Trevarrow, an Auburn Hills, Mich.-based distributor of Wolf and Sub-Zero appliances including ones for outdoors, has seen double-digit growth in its outdoor appliances business.

"We are seeing them become more popular," says Don Cooper, Trevarrow’s corporate sales manager. "What was once thought of done only in warmer climates, like Arizona, ideally you can get eight to nine months out of it here (in Michigan)."

Cooper says it’s easy to deal with the winter cold with outdoor heaters.

Russ Faulk, vice president of design and marketing for Kalamazoo Outdoor Gourmet, says outdoor kitchens "are more rivaling the indoor kitchen than they used to."

The company specializes in outdoor cooking and entertaining. It has a manufacturing facility in Kalamazoo, and its headquarters are in Chicago.

"We are the upper end of the upper end," Faulk says. "Our average outdoor kitchen order is in the $30,000-$50,000 range in the appliances and cabinetry."

Faulk says the outdoor pizza oven is the top seller.

Outdoor kitchens can include cooking areas with refrigerators and ice makers designed and built for outdoor use that cost several thousand dollars each. There also are shiny built-in stainless steel kitchen sinks and even dishwashers. They’re all designed to be weather-resistant.

"It’s been growing for the last five-six years," says Dominick Tringali, staff architect for Moceri, a custom home builder. "We are seeing more of those kinds of spaces."

A Moceri-built home undergoing reconstruction has a covered space with a stone base island with a Sub-Zero built-in dishwasher, storage drawer and a warming drawer. It features another base with a refrigerator, cupboard storage and a Wolf grill. Moceri estimates there’s at least $35,000 in appliances.

"There’s more interest in improving outdoor space," Frank Moceri says. "People are finding a better investment in outdoor space and something they can enjoy after the kids leave home."

What you spend depends on what you want or need. Builders and designers peg pricing from $15,000 to upward of $50,000, depending on size, materials and appliances.

The Hearth, Patio and Barbecue Association (HPBA) puts outdoor rooms in the leisure lifestyle category and says it’s a $6.2 billion industry.

"The options are enormous and for all weather, even in Detroit," says HPBA spokeswoman Leslie Wheeler. "You can custom make it to fit your lifestyle. If pizza is your favorite, plan on a pizza oven."