Did I lock the front door? Did I shut the garage door?

Those paranoid days are over for the Smiley family. Last spring, they transformed their charming 1950s Brooklyn Center rambler into a "smart home." It took less than a day.

Using their smartphones, Brian Smiley and wife Lindsey Peterson-Smiley lock their front door and adjust their thermostat. They can control small appliances and check a log of all entries and exits from their home. They can even take a peek to see if their teenage son is finishing up his chores by using the system's live video feed.

"I am not a first adopter by any stretch, but I do like the ease of use and the features," said Peterson-Smiley.

Once the purview of the wealthy, such features in smart homes are now in reach of the middle class. According to one industry study, 90 million homes will be automated worldwide by 2017. The game changer in the past two years has been the rise of smartphones and tablets, experts say, which makes it easy and affordable to control household systems remotely.

"We are basically walking around with a $500 remote control," said Dave Pedigo, senior director of learning and emerging technologies with the Custom Electric Design & Installation Association. "Now we have the controller in our hands and the cost of the hardware is becoming very inexpensive. It makes it easy to pull it off."

The Smileys opted for Vivint's full home automation package, which cost $199 for activation and $68 a month. Vivint, originally a home security company with nearly 700,000 customers, started offering smart home technology at the end of 2010.

Since then, about half of Vivint's new customers utilize at least one smart home feature. Vivint is based in Provo, Utah, but has 100 employees working at one of its two North American monitoring stations in South St. Paul.

There's also increased sales in custom smart home systems, which, thanks to smartphone technology, are more affordable and accessible than ever, said Bob Cushman with Home and Commercial Electronic Systems in Hudson. Custom systems allow people to control everything from security cameras to their sprinklers and window blinds.

And it's not just for new construction.

"A lot of the stuff is retrofitable and wireless. It doesn't matter how old your house is," Cushman said. "There's a solution that works for every home."

Upgrading the home

The Smileys first started looking at smart home technology when they decided to upgrade their antiquated security system.

They recently bought Brian Smiley's childhood home from his parents. They knew a neighbor across the street had once had a break-in, so they wanted a more cutting-edge system that their two children would feel comfortable using.

Brian Smiley said he was shopping with an eye toward smart-home features.

"I like gadgets," said Smiley, who works for the state unemployment division.

Vivint technicians were installing a system at a neighbor's house when they stopped by the Smileys. They installed the system that same day.

It immediately made life a little easier for the kids, who now use key fobs to enter the home. There's also a panic feature on the fob that the children can push in emergencies.

The Smileys receive text messages if there's unusual activity at the house, including a door unexpectedly opening or temperatures falling dramatically. There's a weather feature -- which helps their 8-year-old daughter get dressed for school - and a severe weather alert feature.

Jimmy Bahnson, Vivint's lead field service professional in the Twin Cities, said the weather alert feature saved lives when a tornado ripped through Joplin, Mo., in 2011.

The Smileys' son, Dylan Peterson, is a bit more measured about the automation and live video feed, which has caught him watching television instead of doing homework.

"That's useful for them," Dylan Peterson said.

The Smileys estimate that the smart home system has helped them reduce heating and cooling costs. Last summer, Brian Smiley said he'd keep the house at 80 degrees while the family was out and then turn up the air-conditioning with his phone when they were on the way home.

"You think it's about convenience first and foremost. There is also an aspect of return on your investment," Pedigo said. "You will have the ability to reduce your energy consumption."

The smart-home features have saved the Smileys some worry, especially when the kids are home alone.

"It was something deemed such a luxury years ago," Bahnson said. "Now just about anyone can have it if they really value it."

Shannon Prather is a Twin Cities freelance writer.