Burglary Protection for Renters: Smart Tech, No Drilling

The police are clear about the order: they recommend mechanically securing all windows and doors so that uninvited guests do not get in in the first place (Polizeiliche Kriminalprävention). The share of attempts shows that prevention works. In 2025, nearly half of all burglaries, 44.9 percent, failed (Polizeiliche Kriminalprävention). German insurers see it the same way: electronic systems can usefully complement basic mechanical protection, but they do not replace it (GDV). The first step therefore costs nothing but habit.

When it comes to hardware, renters quickly hit a limit. A cross-bar lock, for example, is anchored firmly in the masonry with strike boxes (K-EINBRUCH), and additional locks and hinge-side security bolts are screwed into the door and frame. Those are structural changes you clarify with the landlord first. A lockable window handle is simpler: German insurers name it as protection against so-called window drilling and against glass breakage (GDV). Many models fit the existing mount and are attached with the screws of the old handle. Keep the original handle so it can go back in place when you move out. The role of the lock cylinder and a smart lock on the apartment door is explained in our guide choosing a smart door lock.

A contact sensor has two parts: the housing with the battery sticks to the frame, the magnet sits opposite on the moving sash, or the other way around if space requires. What matters is the gap between the two when closed, which the manufacturer states in the manual. Clean the spot first with a little dish soap and water or rubbing alcohol, let it dry and press the pad firmly for a few seconds. Tape sticks less well in the cold, so in winter attach the sensors at room temperature and not with the window open. Then test every sensor individually: open the window, tilt it, close it and check in the app whether the status is correct.

The check when leaving the apartment is handy in everyday life. Many systems can show which window is still open or tilted. That puts the police advice to treat tilted windows as open ones into practice without walking through every room. Sensors belong above all on the apartment door, on windows and balcony doors on the ground floor or raised ground floor, and on windows that can be reached from a canopy, a garage or a balcony. Third-floor windows without a balcony come last.

A light that comes on in the living room in the evening makes an apartment look lived-in. German insurers explicitly name timers as a way to control lighting automatically while you are away and to simulate presence (GDV). In a rental, a smart plug on the floor lamp or a smart bulb in the existing socket is enough. A fixed schedule from 5 to 10 pm is a start; a time window that shifts by a few minutes every evening and follows the sunset looks more convincing. How to plan lights and shutters for longer trips is covered in detail in our article burglary protection while on vacation. We also set up smart lamps with schedules through our smart lighting service.

Devices that only plug in, stand or stick do not change the apartment permanently. A short note to the landlord or property manager still makes sense, especially for sensors on the apartment door, a loud siren and adhesive pads on delicate painted frames. The police explicitly advise renters to discuss burglary protection measures with the landlord; with the landlord's consent they can be implemented in a rental too (K-EINBRUCH).

For anything that is drilled or screwed on, the law gives renters a tailwind. The tenant can demand that the landlord permit structural changes to the rented property that serve burglary protection (Section 554 BGB). The claim does not apply if the change cannot reasonably be expected of the landlord even after weighing the tenant's interests. Tenants can commit to providing an additional security deposit for the change, and a contractual deviation to their disadvantage is invalid. A right to permission is not yet permission, though: install only once consent is in place.

Put the agreement in writing. In many buildings, communication still happens verbally: 82 percent of renters use the phone to reach their property manager or landlord (Bitkom). A call is a good start; a short email or letter afterwards makes the consent provable when you move out. These points belong in the request:

If a bigger upgrade is on the cards, such as a burglar-resistant apartment door or a cross-bar lock, the German development bank KfW funds it with a low-interest loan of up to 50,000 euros per housing unit in its age-appropriate conversion program (KfW). Tenants are eligible too, but only for projects in their rented home; KfW recommends that they conclude a modernization agreement with the landlord under Section 555f BGB (KfW). Funding only covers work that a specialist firm carries out to the technical minimum requirements; do-it-yourself work is not eligible (KfW). For a few sensors you stick on yourself, this route is therefore out of the question, but for a new door it is worth considering.

Smart security tech is itself a device on the network, and that is exactly what worries many people: 83 percent of smart home users worry that smart devices could be hacked (Bitkom). Everyday practice feeds that worry. 38 percent use the same password for many of their smart home devices, and 27 percent rarely install available software updates right away (Bitkom). The police warn that offenders could use poorly secured home technology to spy on residents' habits and whether they are home, and use that to prepare a burglary (K-EINBRUCH). A sensor that reveals when nobody is home would be the opposite of protection.

How to secure your router and home network in general is covered in our article securing your home router; which settings improve privacy on smart devices is explained in our guide setting up a secure, privacy-friendly smart home. If you want to combine devices from different manufacturers, look for a common wireless standard; our article Matter explained shows what the standard does and where its limits are.

Think about power and internet as well. Battery-powered sensors keep reporting, but without the router no message reaches your phone, and a siren without its own battery goes silent with the power. Check whether the hub and siren have a backup power supply, and replace batteries before the app warns you. What still works during a power outage and how to prepare is shown in our article power outage at home.

Technik daheim is not a locksmith and does not install certified alarm systems. For tested locks, cross-bar locks and standard-compliant intrusion alarm systems, specialist firms and the police crime prevention advice center are the right contacts. We take care of the smart part: in the Hildesheim area and the Leine valley we come to your home, stick door and window contacts in the right places, integrate motion detectors and a siren, configure notifications without constant pinging and set up lighting schedules. More on our smart home setup page.

If you would like an indoor camera as well, we set it up so that it only shows your own apartment, stores recordings locally if you wish and switches off when you are home; details on our security cameras page. If the Wi-Fi does not reach the apartment door, a Wi-Fi optimization helps. We support older relatives patiently and without jargon, more on tech help for seniors. You can book an appointment via the contact form; before that, note how many windows and doors you want to secure and whether the landlord has already agreed.