1. Upgrade Your Lock Cylinder
The cylinder is the part your key goes into. If your home has a basic cylinder with no security rating, it can be picked or bumped in under a minute. Upgrading to a certified cylinder is the single most impactful security improvement you can make, and it costs €50–€120.
In the Netherlands, look for SKG certification. SKG 1-star resists basic picking. SKG 2-star resists bumping and picking (recommended minimum). SKG 3-star resists all known non-destructive entry methods (recommended for front doors).
In Germany, look for VdS certification, which follows a similar tiered system. The Deutsche Versicherungswirtschaft (GDV) recommends at least a VdS Class B cylinder for residential front doors.
Replacing a cylinder is a 15-minute DIY job. You remove one screw, slide out the old cylinder, and slide in the new one. No locksmith needed unless your door has an unusual configuration.
2. Reinforce the Strike Plate
The strike plate is the metal piece on the door frame where the bolt slides in. On most doors, it's attached with short screws (15–20mm) that go into the door frame only. A hard kick can rip these screws out of the wood, even with a high-quality lock.
The fix is simple and costs about €15–€25: replace the standard strike plate with a security strike plate that uses longer screws (75–100mm) that reach into the structural stud behind the frame. This turns a 2-second kick-in into a serious effort that makes noise and takes time — both things burglars want to avoid.
In the Netherlands, a veiligheidssluitplaat with 3-inch screws is standard advice from politiekeurmerk-certified security advisors. In Germany, look for a Sicherheitsschliessblech.
This is arguably the most underrated security upgrade. A €20 strike plate with proper screws stops more break-ins than a €200 lock on a weak frame.
3. Add a Door Sensor
A door sensor tells you when your door opens, how long it stays open, and whether it's properly closed. On its own, it doesn't prevent entry — but it gives you immediate awareness, which is the first step in any security response.
Standalone door sensors (like those from Aqara, Eve, or Nuki) send a notification to your phone whenever the door opens. You can set custom alerts: notify me if the door opens between midnight and 6 AM, or if it stays open for more than 5 minutes.
When paired with a smart lock, the door sensor becomes more powerful. It can trigger auto-lock when the door closes, verify that the deadbolt engaged after you left, and create a complete log of door activity. You get the equivalent of a security guard's logbook — but automatic and always on.
Cost: €30–€50 for a standalone sensor, or included with smart lock systems.
4. Install a Smart Lock with Activity Log
A smart lock adds two security features that physical locks fundamentally lack: an activity log and auto-lock.
The activity log records every lock and unlock event — who did it, when, and how (app, key, PIN code, fingerprint). This gives you complete visibility into your door's usage. If there's ever a security incident, you have exact timestamps. If you suspect someone accessed your home while you were away, you can check instead of guessing.
Auto-lock ensures the door is always locked. Forgetting to lock the door is one of the most common security failures — and it's one that no physical lock can prevent. A smart lock with auto-lock removes human error from the equation entirely.
Nuki's Smart Lock Pro Pro with the Door Sensor 2.0 provides both features. Every entry is logged, and the door auto-locks when the sensor detects it's closed. Combined with a quality cylinder (tip 1) and a reinforced strike plate (tip 2), you have a genuinely hardened entry point.
5. Consider a Security Camera or Video Doorbell
A camera or video doorbell adds visual deterrence and evidence collection. Most burglars avoid homes with visible cameras — it's simply not worth the risk when the neighbor's house doesn't have one.
Popular options include Ring, Google Nest, Eufy, and Reolink. Look for features like: motion detection with person recognition, night vision, two-way audio, and local storage (not cloud-only, to avoid monthly fees).
A video doorbell serves double duty: it's a doorbell and a security camera. When someone rings, you see and speak to them from your phone, even if you're not home. Combined with a smart lock, you can see who's at the door and unlock it for them remotely — all from one workflow.
Important privacy note: in the Netherlands, the AVG/GDPR limits where you can point cameras. Your camera should cover your own property only, not the public street or your neighbor's garden. In Germany, similar rules apply under the BDSG. Check local regulations before mounting.
How These Work Together
Security is most effective in layers. No single device stops all threats, but combined, they create a system where each layer compensates for the others.
A quality cylinder (layer 1) prevents non-destructive entry. A reinforced strike plate (layer 2) prevents forced entry. A door sensor (layer 3) detects entry attempts. A smart lock with auto-lock (layer 4) eliminates human error. A camera (layer 5) deters and documents.
You don't need all five to be significantly more secure. Even layers 1 and 2 (€70–€140 total) put you well above average. Layers 3 and 4 (adding a smart lock) bring monitoring and automation. Layer 5 (camera) adds deterrence.
The key principle: don't rely on a single point of security. A €300 lock on a door with a €2 strike plate and no auto-lock is less secure than a €100 lock with a proper strike plate and auto-lock enabled.