The Renter's Dilemma
Renters want smart home convenience but feel limited by the rules. You can't paint the walls a different color (in most German leases), so surely you can't modify the door lock? The fear is real: modifying the door could mean losing your deposit, violating your lease, or getting a letter from the landlord.
But here's what most renters don't realize: replacing a lock cylinder is not the same as modifying the door. Cylinders are designed to be swapped — that's the whole point of the euro-profile standard used across Europe. You slide the old one out, slide the new one in. No drilling, no cutting, no modification to the door or frame. The door looks exactly the same from the outside.
Do I Need Permission?
In the Netherlands, huurrecht (tenant law) generally allows reversible modifications to your rental. Replacing a cylinder is widely considered reversible — you keep the old cylinder and put it back when you move out. Most Dutch landlords won't even notice, and if they do, they're usually fine with it as long as you keep the original.
In Germany, Mietrecht is similar. Swapping a Schliesszylinder (lock cylinder) is generally allowed without the Vermieter's permission, as long as you keep the original and reinstall it when you leave. This has been upheld in multiple court decisions. Some stricter lease agreements may require notification — check your Mietvertrag.
In Austria, the rules mirror Germany closely. Reversible modifications that don't alter the structure of the Mietwohnung are generally permitted.
The safe approach in all three countries: keep the original cylinder in a labeled bag, take a photo before and after installation, and mention it to your landlord casually if you have a good relationship. Most landlords see it as a property upgrade.
How Nuki Works for Renters
Nuki was essentially designed for renters. The Smart Lock Pro mounts on the inside of your door using the existing cylinder hole. You replace the euro-profile cylinder with Nuki's Universal Cylinder — which fits the same opening, requires no modification to the door, and installs in about 15 minutes with a screwdriver.
From the outside, your door looks completely unchanged. There's no visible technology, no keypad (unless you add one), and no indication that a smart lock is installed. The physical key still works in the new cylinder, so your landlord or building manager can still access with their key if needed (you provide them one).
Everything is battery-powered — no wiring needed. The lock communicates via Bluetooth to your phone. If you want remote access and notifications, you add the Nuki Bridge (a small WiFi adapter that plugs into any outlet near the door) or use the Smart Lock Pro Pro with built-in WiFi.
Moving Out
When you move out, the process takes 5 minutes. You unscrew the Nuki cylinder, slide in the original cylinder you saved, and tighten the screw. The door is exactly as it was before. No traces, no damage, no deposit risk.
You take the Nuki with you to your next apartment. Since it uses the euro-profile standard, it works in virtually any door in the Netherlands, Germany, Austria, and most of Europe. If the cylinder length is different (some doors are thicker), you may need to order a different length of the Nuki Universal Cylinder — but the lock unit itself is the same.
This is one of the key advantages over smart locks that require drilling (like some American brands). Nuki is specifically designed for the European rental market, where non-destructive installation is essential.
What About the VvE/Hausverwaltung?
If you live in an apartment building, the common entrance is typically managed by the VvE (Vereniging van Eigenaren) in the Netherlands or the Hausverwaltung in Germany. You cannot and should not modify the common building entrance — that's shared property.
Nuki installs on your apartment door only, not the building entrance. You still use the building's existing intercom and key system for the main entrance. The smart lock handles just your personal front door.
Some newer buildings have smart intercom systems (like Nuki's own Intercom product) that can be linked to the smart lock, allowing you to buzz yourself in remotely. But this typically requires building-level agreement and isn't something you'd do as a single tenant.