Home alarm: contact and presence sensors that actually warn you in time

The home alarm many people picture is a box on the wall, a keypad, and a siren. In practice, what saves you from a doubt or a scare is something else: knowing which door or window opened, and whether someone is really inside. Without that detail, you only have noise. With sensors placed well, you get a named alert and a house that reacts.

At Integrated House we build that layer on top of the same home network. It isn't a separate system with its own app and its own subscription. It's the same contact sensors and the same presence kit that already serve lights, AC, and scenes—also used for security.

What a useful alarm needs

A useful alarm answers three questions:

1. What opened. Front door, balcony, study window, service door.
2. Whether someone is inside. Hallway motion isn't enough: you need real presence in the rooms.
3. What should happen next. Phone alert, lights, away mode, or nothing, depending on context.

If you only have a siren and a motion sensor in the living room, at three in the morning a cat or a curtain wakes everyone up. If you have the state of every opening and presence by room, the rule can be much finer.

Contact sensors: the home's perimeter

The perimeter is doors and windows. A magnetic sensor on the frame says open or closed. It's cheap, small, and lasts a long time on a battery. With several, the house stops guessing.

For a home alarm in a Medellín apartment, the minimum list is usually:

• Front door and service door.
• Balcony doors and windows that actually open.
• Access to the utility room or storage, if that applies.

When you activate "away" mode, the house checks that perimeter. If something was left open, it tells you with the place name before you go down in the elevator. If something opens afterward, the alert arrives instantly.

That's different from a generic "zone 3" alarm. Here the message is "Master bedroom balcony open." We cover installation and details on aluminum frames, magnets, and the network in the contact sensors guide.

Presence: knowing if someone is there, not only if something moved

The other pillar is presence. Common PIR sensors trip on motion and go blind when you sit still. For security that matters: you want to know if the room is occupied, not only if someone crossed the hallway ten seconds ago.

Kits with mmWave radar detect real presence, including a still person. Combined with openings, the logic becomes clear:

• Away mode and the front door opens → immediate alert.
• Away mode, a window opens and there's no presence in that room → alert.
• You're home, you open the balcony and there's presence → no drama; that's normal use.
• Late at night, presence in the hallway and the service door opens → another story.

The same presence that turns off lights and runs the AC also feeds the alarm. You don't need to duplicate hardware. The detail on mmWave, temperature, and humidity by room is in presence sensors.

What the house can do (without theater)

A good home alarm doesn't have to sound like a building. In a residence, what's useful is usually:

• A notification with the exact place on your phone.
• Lights in the affected area or at the entrance, if it's night.
• Cameras or recording, if you already have them integrated into the same logic.
• Travel mode that arms the perimeter only when you leave and disarms when you return.

The siren can exist. In many Aburrá Valley apartments, though, the neighbor on the other side of the wall isn't your ally at 2 a.m. We prefer rules that notify you first and that don't depend on the building tolerating a racket.

Why we don't leave it in a brand app

There are boxed alarm kits ready to go. They work until the manufacturer's cloud fails, changes plans, or stops supporting the model. In Medellín, on top of that, building Wi‑Fi is already fragile between walls: putting every sensor into that fight is asking for failures.

That's why battery sensors go on Zigbee or Thread, and the repeaters are mains-powered devices (switches, plugs, presence kits). The logic lives on the home server. Internet is for alerting you when you're out; it isn't the main switch. The network criteria are the same as in the Zigbee and Thread guide.

How we set it up in your home

We start with a visit. We look at doors, windows, blind spots, and how day-to-day life works: who arrives first, whether there are kids, pets, household help, or long trips. Then we propose the contact perimeter and the rooms where presence changes the rule.

We integrate what already speaks an open protocol. We replace only what won't cooperate. In the end, every sensor has a real name in your app, "away" mode arms what it should, and alerts arrive with context, not an opaque code.

A well-built home alarm is almost invisible on quiet days. It shows up the day the study window opens when nobody should be there, and you already know before you wonder if it was the wind. If you want us to review your home in Medellín, write to us from the site.