# How to secure a storage unit against theft: proven methods Doors, locks, alarms, a bike anchor and insurance: what actually protects a storage unit from burglary, and what to check before you rent or buy one. [See the full page](https://maszbox.pl/en/blog/jak-zabezpieczyc-komorke-lokatorska-przed-kradzieza) - Author: [Marsel Zychowski](https://maszbox.pl/en/autor/marsel-zychowski.md) - Published September 20, 2026 - Updated September 29, 2026 ![A storage unit door locked with a heavy padlock and a bike locked to an anchor](https://maszbox.pl/images/blog/okladka-jak-zabezpieczyc-komorke-lokatorska-przed-kradzieza.webp) You come back to your storage unit and find the door forced, or an empty space where the bike used to be. The loss can hurt, and it often happens because the unit had the weakest security in the whole building: the same open slatted door with a padlock as twenty years ago. Below you will find concrete ways to change that before something happens, rather than after the fact. The data and standards described are Polish, because that is where the listings on Maszbox.pl are located. ## How big is the risk? The data nobody mentions Figures from the Polish National Police Headquarters for 2021 show that more than 13,500 bicycles were stolen in Poland that year, of which 3,746 cases took place in multi-family buildings, meaning basements, storage units and bike rooms among others, and 1,222 on roads and streets. ![Chart of bicycle thefts in Poland in 2021: 3,746 from multi-family buildings and 1,222 from streets and roads](https://maszbox.pl/images/blog/kradzieze-rowerow-2021-wykres.webp) *Data from the Polish National Police Headquarters for 2021.* Theft inside buildings therefore happens more than three times as often as in public space, contrary to the common belief that a bike is safer left inside than on the street. These figures are a few years old and are the most recent readily available ones, but the direction is clear: a storage unit is not automatically a safe place. ## Door and lock - the first line of defence The weakest link in most units is the door: thin, open slatted, screwed together from battens, and possible to tear apart without tools. A solid steel door in resistance class RC2, or RC3 for more valuable contents, set in a brick wall, is the baseline. Add two independent locks or one multipoint lock, plus a certified hardened steel shackle padlock. An ordinary luggage padlock makes no difference at all. If you are wondering how the individual constructions differ, we described them in the article on [storage unit construction types](https://maszbox.pl/en/blog/zabudowa-komorki-lokatorskiej-rodzaje-materialy.md). ## Alarm and CCTV - is it worth it for a storage unit? For a single unit a full alarm system is often overkill, but a simple wireless sensor, either magnetic on the door or vibration based, with a GSM notification to your phone, costs little and genuinely shortens the response time. CCTV mainly makes sense at the level of the whole basement corridor. That is a decision for the association or the building manager rather than an individual owner, but it is worth raising at a residents' meeting. ## How to secure a bike and other valuables inside Since bikes are the most common target, lock them with a steel cable or chain to an anchor fixed into the wall or floor, not to a pipe or a radiator, because those are easy to cut or pull out. Power tools and seasonal equipment are better kept in a lockable metal box inside the unit - an extra obstacle even once someone is already in. It is also worth noting down the serial numbers of valuable items and photographing them, because that helps when you file a claim. ![Bicycle locked with a steel cable and padlock to an anchor fixed into the wall of a basement corridor by the storage units](https://maszbox.pl/images/blog/rower-przypiety-w-komorce-lokatorskiej.webp) ## Insuring the contents of a storage unit - what to remember A standard home insurance policy usually also covers movables kept in a storage unit, but often on condition that minimum security requirements are met, meaning the type of door and the class of lock. Check that in the policy terms before a loss, not after. If you keep something valuable in the unit, for example a bike, sports equipment or tools, consider extending the policy specifically to burglary of an appurtenant space. That is usually a separate item rather than something automatic. ## What to check for security before renting or buying a unit If you are still looking for a unit, whether [to rent](https://maszbox.pl/en/komorki-lokatorskie/na-wynajem.md) or [to own](https://maszbox.pl/en/komorki-lokatorskie/na-sprzedaz.md), view it in person before deciding and check: - the type of door, meaning a brick space with a solid door rather than mesh or open slats, - whether the stairwell or basement corridor has an intercom or access control, - whether the building has CCTV, at least at the entrance to the basement. The same questions are worth asking before you publish your own listing. Security features described well in the listing genuinely speed up the tenant's or buyer's decision, and the publishing rules are on the [how to add a listing](https://maszbox.pl/en/jak-dodac-ogloszenie.md) page. ## What to do after a break-in - step by step 1. **Do not tidy the scene before reporting it** - photos taken straight away help both the police and the insurer assess the loss. 2. **Report the break-in to the police** - you will need the case number to file a claim. 3. **Inform the manager or the association** - other residents should know there has been a break-in in the building. 4. **File the claim with your insurer** with the case number and photos of the items, which is where the earlier advice about serial numbers pays off. 5. **Consider upgrading the lock or the door** - it worked once, so someone may try again. ## Marsel Zychowski MaszBox Team We share practical know-how on renting and selling space - garages, warehouses, storage units, parking spots and more. ## Questions about securing a storage unit ### Is an ordinary padlock enough to secure a storage unit? An ordinary luggage padlock or a low resistance class is practically no obstacle, because it opens in a matter of seconds. A certified hardened steel shackle padlock is an entirely different category of security. ### Is it worth reporting a minor theft from a storage unit if the loss is small? Yes. Even for a small loss, reporting it gives you the case number needed to settle an insurance claim, and it builds the statistics that help the association justify investing in better corridor security. ### Does home insurance automatically cover a storage unit? Usually yes, but with caveats about minimum security measures. It is worth checking in the policy terms before a loss rather than counting on it without verifying.