There’s something about the holidays that gets me thinking about home security. Maybe it’s reading on Nextdoor about rampant neighborhood porch piracy, or maybe it’s a recent stovetop mishap setting off the smoke detector. Even more troubling, maybe it’s the occasional power outage that disconnects me from the security call center, because my home phones, which use Internet, are dead. Am I as protected as I could — and should — be?

In the early 1980s, installing a home security system meant drilling holes into window and door frames, screwing in sensors and running wires through walls to a central keypad, all powered by a large battery tucked away in a basement or closet. If you went all in, maybe you had a hard-wired smoke detector, too. That was pretty much the norm for homeowners, including me (my security system dates to 1999), until high-speed Internet, ultrafast wireless and smart home technology became the norm.

Goodbye wires, forgetting to arm your home or fretting if the electricity fails. Hello self-adhesive sensors, high-definition infrared cameras, app-based remote arming and touch-screen panels.

“The past 10 years or so have been amazing for home security,” says Tim Rader, senior director of product development and engineering at ADT, one of the leading suppliers of home security, with more than 6 million residential and commercial customers. “The pivot from wired to wireless allowed companies to install sensors in places we couldn’t get to before. Then, fast-forward to next-gen systems, with smart home technology that can immediately identify if a window has been broken or in what room a fire has started.”

Wireless technology has also paved the way for homeowner-installed systems, says Doug Woodard, chief customer experience officer with SimpliSafe, which launched DIY home security products in 2006. “People are increasingly comfortable with installing and connecting home technology. Now they have an accessible and affordable way to customize and install their own security system with no long-term contract,” he says.

Whether you’re thinking about installing a new home security system or just want to upgrade your setup, there are some factors to consider. Even the most basic of online searches will return dozens of comprehensive reviews of home security systems, which is a good place to start.

Jeffrey Zwirn, a forensic alarm science and security expert in Tenafly, N.J., says a properly designed system can save your life, but one size does not fit all. Start by asking yourself some questions. What are you trying to protect and/or guard against? Are you worried about break-ins, fires, carbon monoxide poisoning or a burst pipe flooding your basement? How important is customization? Do you own or rent your home? Renters or those planning to move in a few years may want the flexibility of a DIY system, so they can take it with them when they move.

If you opt for professional installation, contact multiple companies willing to survey your home in person. “A pro can assess the home and the people who live there,” Zwirn says. You might also want coverage beyond the basics. For instance, if you don’t hear well, you may need multiple loud sirens. Or your home may need smoke detectors inside and outside each sleeping area. “This is one purchase where you may want to leave it to the professionals,” he says.

Zwirn says to beware of products or components that may not be up to national standards and codes. He suggests you get the make and model of everything being installed, then cross-check that each is UL compliant — meaning it is certified by UL, a global safety certification company — by searching for the product at productiq.ulprospector.com/en.

Rader says other initial queries should include: How long has the company been in business? Will the products work together? Who will do the installation: the company or a third-party subcontractor? Zwirn recommends dealing directly with a company instead of with an authorized dealer who may just be an intermediary. Expect to pay between $1,500 and $2,500 for a professionally installed system, Zwirn says.

For homes with systems that are more than 15 years old, you may want to consider upgrading. Contact your security provider for a free reassessment. According to Rader, you may only need to replace a few elements. Some wireless sensors can even be integrated into wired systems. The biggest change will probably be getting an upgraded keypad or touch-screen control panel. Although new panels typically use WiFi, they have a built-in battery-powered cellular module (a glorified micro cellphone) and battery backup, which should last at least 24 hours. In the case of a power or Internet outage, your system can still communicate with the security’s monitoring center.

You may also want to consider add-ons such as temperature sensors, water sensors or glass-break sensors. If nothing else, during the assessment, have the technician test your fire alarm. This is the one component you can’t self-test, and it should be checked annually, Zwirn says.

Those who want to save money while having flexibility may prefer the DIY option. Systems such as SimpliSafe, Ring, Blue by ADT and Abode Home Security typically offer peel-and-stick window and door sensors. These, plus additional components, such as smoke and carbon monoxide detectors, glass-break detectors, outdoor cameras and sirens, all wirelessly communicate over radio frequencies with a base station that plugs into an electrical outlet.

You can choose the kind of sensors you want and where to place them. Setup is easy using the keypad or a smartphone. An average DIY package costs about $200 to $600, with additional costs for more sensors, cameras and monitoring. One consideration when selecting the DIY option is whether you have a smartphone, because some systems require an app for setup and monitoring. If you don’t own a smartphone, you should probably stick with a professionally installed system.

No matter the security system, perhaps the most important factor is the call center — your emergency lifeline. When an alarm triggers, specialists contact first responders using direct lines of communication, not by using 911. In the past, call centers were secured facilities monitored 24/7, so someone was always there when needed. According to Zwirn, with the coronavirus pandemic, numerous operations allowed employees to work from home, and although many are now restaffed in person, some continue to use remote monitors.

“During an emergency, the alarm company is your partner,” Zwirn says. You don’t want someone working remotely who steps away from the monitor to let the dog out or who loses connection. Whether the security company owns and operates the call center or contracts with a third party, it should give you a guarantee in writing that its call center employees are not working from home. And although some DIY systems allow for self-monitoring, it’s not advisable.

Whether you are starting from scratch or upgrading your system, the bottom line is to know what you are getting. “You don’t want a false sense of security,” Zwirn says. “With an alarm system, you don’t have the luxury of a second chance.”