But it isn't likely to be anything like your grandmother's painted wood or silver-gray aluminum screen door, says Steve Melman, a spokesman for the National Association of Home Builders.

"Many of today's homeowners want added security, increased energy efficiency and casual living, with easy access in and out of the house," Melman says. "Today's storm doors address all three of those issues."

A storm door is installed in front of an exterior door to allow for outside views and ventilation when the main door is open during warmer months. When the primary door is closed, a storm door can be an additional barrier for greater security or energy efficiency.

Tim and Anne Nelson live on a lot with many trees in Summerfield, N.C. They had a new storm door installed two years ago at the front of their three-story house.

"It was important for the storm door to look good from the curb, but we also wanted it to be a secure door," Tim Nelson says.

It features a full-view panel with break-resistant glass and a three-point locking system. The door's hunter-green trim was chosen to match the dark green of the steel roof panels.

Most storm doors are sold as pre-hung units for standard exterior doors, which are typically 32 or 36 inches wide by 80 inches high. Larger and smaller openings can be fit with custom-made doors, and double-door kits are available. Storm doors can be hinged on either side and screw into existing jambs.

Major brands such as Larson, Pella and Andersen allow you to design your own door online. Based on the options purchased, expect to pay $100 to $450 for a storm door, uninstalled. A warranty is often a good indicator of quality, but there are other considerations.

The door's construction: Wood clad in a vinyl or polypropylene exterior is a scratch- and rust-resistant option and tends to be the least expensive material choice. Solid wood clad in aluminum or insulated aluminum features a baked-on enamel finish. The surface doesn't need to be painted but is not scratch-resistant. A 16-gauge steel frame with a durable powder-coated paint finish is a heavy-duty option that adds another layer of security.

Colors and hardware: The color of your storm door's frame should not compete with the primary exterior door. Choices can include white, off-white, gray, brown, green, black and red. Choose the same metal finish for your storm door's locks and hardware that are on your primary exterior door. The handle should complement the home's architecture and the exterior door's hardware.

The glass design: A full-view glass panel is best if you want your front door visible from the curb or a maximal view outside when the primary door is open. A mid-view glass panel features a solid panel at the bottom third of the door. Decorative glass can be beveled, etched or tinted. Laminated glass can be break-resistant, block most of the sun's ultraviolet rays, and increase a storm door's insulation value.

For added ventilation, many storm doors have retractable screens - no more changing out windows for screens (and vice versa) with the changing of the seasons.

"A screen is stored in a hidden cassette at the top of the storm door, which moves into place as the glass is lowered," says June Eng, a spokeswoman with Larson Manufacturing. "Raise the glass back up, and the screen rolls back up into its housing."

Expect to pay just under $300 for a basic storm door that features this option, which Larson calls Screen Away. Andersen's retractable screen is found in the Store-in-Door series, while Pella touts its Rolscreen collection.

"The storm door has really been reinvented in the past two years," Eng says. "There are more options for insulation and safety, using better materials and locking systems, all without compromising its front-door appeal."

The Nelsons' storm door is a functional gateway to the great outdoors.

"Even though the light comes pouring in through the storm door, we don't have to worry about sun-fading, since the glass blocks the ultraviolet rays," Tim Nelson says.

"Our storm door acts like a big picture window to the outside world."