Many cat owners are familiar with the problem:
The cat should be able to enter the house independently – but leaving the door permanently open is not an option. A clever idea is therefore to leave the door slightly ajar with a gap limiter so that the cat can pass through.
But does that really work – and how safe is this solution?
🚪 The Idea: Door Gap as a Cat Door
With a door security device like the model from Scheffinger, the front door can be opened a small crack, usually about 10–11 cm.
The advantages are obvious:
- The cat can go in and out independently
- The door remains secured
- No structural changes (e.g., cat flap) necessary
Sounds like the perfect solution – right?
🐱 Can Cats Really Fit Through 11 cm?
Yes – and surprisingly easily.
Cats are extremely flexible. What matters is not their body girth, but the size of their head.
Rule of thumb: If the head fits through an opening, the rest of the body almost always follows.
This specifically means:
- Most domestic cats only need 6–8 cm of space
- An 11 cm wide door gap is generally more than enough
- Even larger cats often manage – as long as they are not severely overweight
👉 Conclusion:
A door gap works very reliably as a cat passage.
🔐 But how safe is it?
This is where it gets a bit more critical.
A door with a gap is not comparable to a closed door. Even if a security device is installed, certain risks arise:
- The gap offers visible access from the outside
- With simple tools (e.g., wire), handles could be reached
- Doors can potentially be pried open or manipulated
👉 Important to understand:
Such security devices are more of an opportunistic deterrent than complete burglar protection.
⚖️ Comfort vs. Security – An Honest Assessment
This solution always operates in the tension between convenience and security:
Advantages:
- No structural intervention
- Immediately implementable
- Ideal for spontaneous or temporary use
Disadvantages:
- Limited burglar protection
- Dependent on door, lock, and surroundings
- Not suitable for every residential area
🧠 Who is this solution suitable for?
A door gap can work well if:
- you live in a quiet residential area
- the door is not directly visible from the street
- you only use the solution temporarily (e.g., in the evening when you are home)
It is less suitable for:
- Ground-floor apartments in busy areas
- Easily accessible front doors
- Increased security needs
🐾 Better Alternatives for Permanent Solutions
If your cat is supposed to go in and out regularly, these options are usually superior:
- Cat flap (classic or chip-controlled)
- Window solution with insert
- Electronic access systems for pets
👉 These offer significantly more comfort and security in everyday life.
🔎 Conclusion
A door gap with security can indeed function as a cat passage – and is a practical temporary solution.
