Landlords: You Cannot Put A Camera In. You Cannot Trust A Key. Here Is What Goes In Instead.Landlords: Every Key You Ever Handed Out Still Works. Here Is How You Find Out When One Gets Used.Landlords: Know When The Flat Is In Use And When Every Door Opened. 86.45 Euros, Once, No Monthly Fee.
SHWritten by the Shelly teamPublished by Shelly Europe · 14 September 2026
Who this is for
Anyone who lets a property, for a weekend or for three years
Anyone who has handed over a key and not got it back
Anyone paying monthly for an alarm that has never told them anything
Anyone with a second place that stands empty part of the year
Two questions keep every landlord awake. Who can get in. And is anyone in there right now.
A key answers neither. It opens for whoever holds it, it never says who that was, and every copy ever cut is still out there. A camera would answer the second one, and since April 2024 you are not allowed one inside a let.
So the two questions sit there. Two sensors answer the second one tonight, for less than four months of an alarm contract. A smart lock answers the first.
Here is what each piece does, and why.
Count the keys to your rental. Not the ones in your drawer. All of them.
The tenant. The one before. The cleaner, the builder, the agent. A copy costs two euros at a market stall and leaves no trace. Changing the lock costs 80 to 150, which is why nobody does it, which is why every key ever handed over still works.
The way out is to stop handing out keys. A lock that gives each person a digital key, ending on the day you set, does that. Until then, door sensors tell you every time a key is used.
Here is how the pieces fit together.
86.45 euros, once. Against a monitored alarm at 25 a month, which is 300 a year forever and still cannot tell you who opened the door.
The sensor tells you the flat is in use, and when, with no picture and no sound, which is why it is allowed where a camera is not. The two door sensors put a time on every open. A smart lock, offered straight after, replaces the key.
Paid once, and the hardware is yours.
Here is what each piece does.
The short version
Every key you have handed over is still out there. A lock that works on digital keys ends that on the day it is fitted.
An indoor camera is banned on short-let platforms and breaks privacy law in any let. A presence sensor is not a camera: it records that a room is in use, with a time, and nothing else.
Two door sensors put a time on every open and close, so the log says when, not just that.
The presence sensor and two door sensors: 86.45 EUR, once. No monthly fee. The lock is offered on the next page, below its shop price.
The first question: who can get in
A key is a password that never expires and cannot be changed without a locksmith. Everyone who has ever held one can still use it.
~2 EUR
What it costs to copy an ordinary key, at any market stall, in about four minutes.
80 to 150 EUR
A locksmith changing the cylinder. Per door, per tenancy, which is why it does not happen.
0
Keys anyone holds once the lock works on digital keys. The plumber's key stops working on Tuesday afternoon by itself.
✓Everybody gets their own digital key. Guest, tenant, cleaner, the neighbour who waters the plants. Not one shared key between them.
✓Keys end by themselves. Set the cleaner's for Friday morning and it stops working on Friday afternoon. Nothing to collect.
✓You see whose key opened the door, and when. Not that someone did. Which key did.
✓Lock up from wherever you are. If a guest forgets, you lock the door from your phone.
The LOQED Touch Smart Lock 2S mounts over the euro cylinder already in the door and opens with a touch once your phone is recognised. It is offered straight after the sensors.
The second question: is anyone in there
An empty property is the one you worry about. The flat between bookings, the second home in February. You want one thing from it: to know if it is being used, and when.
If you let on a platform
Every indoor camera, banned since April 2024
Not just badly placed ones. All of them, anywhere inside a listing, even switched off. Break it and you can lose the listing.
Whoever you let to
Privacy law does not cover a flat you let
You may film your own home. Letting is a business, so that cover stops. Filming tenants or guests without consent breaks the law, not a house rule.
The sensor in this kit uses radar, not a lens. It knows a person is in the room even when they are sitting still, and it records nothing about them. No picture, no sound. What you get is a line in a log: living room in use, 23:10 to 03:40.
It does not count people, and nothing lawful will. It tells you the room was in use and when. If a booking said two and the place was busy until four in the morning, that is what you know. Write the rest into the house rules, not into the sensor.
The third piece: a time on every door
The two door sensors are the cheapest part and the one people forget. One on the front door, one on the terrace door or the store room. Every open and every close gets a time.
Fri 15:02Front door: opened
Fri 15:03Living room: in use
Fri 23:48Front door: opened
Sat 00:10Front door: opened
Sat 00:31Front door: opened
Sat 04:12Living room: not in use
What a Friday night looks like in the app. Three door opens after midnight and a room in use until four. No picture of anyone. Enough to have a conversation.
What landlords buy instead
1
A monitored alarm contract
Twenty to forty euros a month, forever, and it knows a door opened. It does not know who, and it does not know whether anyone stayed. Cancel and you own nothing.
2
A lockbox with a spare key
Everyone who has ever had the code has the key. And the key is still a key.
3
A camera pointed at the hall
Banned on the platforms, unlawful in any let, and it is the thing guests look for first. One review that says "found a camera" is worth a season of bookings.
What this actually is
Shelly Presence Gen469.90 EURRadar, not a lens. Knows a room is in use even when the person is sitting still. Records no picture and no sound.
Shelly BLU Door/Window ZB17.90 EUR eachTwo parts, one on the frame and one on the door. Logs every open and close with a time, and notices a tilted window.
LOQED Touch Smart Lock 2S248.90 EURReplaces the key. A digital key per person, ending on the day you set. Lock and unlock from your phone.
Smart Security BundlePresence Gen4 and two door and window sensors
Member of the SDAXGermany's DAX index family, since April 2026
Awarded
CES 2025Residential Systems Picks Award
Works with
Speaks Matter, Zigbee 3.0, Z-Wave, Bluetooth and Wi-Fi, so it also joins whatever you already run.
What the usual answers cost, against paying once
Year one, doing it the usual way
A monitored alarm contract, at 25 EUR a month300 EUR a year
Changing the cylinder once between tenants80 to 150 EUR
A lost-key fee you will never manage to collect25 to 100 EUR
Year one405 to 550 EUR
The alarm line repeats. Three years of a 25 EUR contract is 900 EUR and you still own nothing at the end of it. The kit below is paid once and moves house with you.
Introductory offer
Know when the place is in use, and when every door opened. 86.45 EUR, once.
The presence sensor tells you the flat is occupied, and when. The two door sensors put a time on every open and close. 86.45 EUR against 101.70 bought separately, no monthly fee. The smart lock is offered on the next page, below its shop price.
Shelly Presence Gen469.90 EUR
Shelly BLU Door/Window ZB, two35.80 EUR
Introductory price 101.70 EUR86.45 EUR
✓You know the flat is in use, and when. A radar sensor, not a camera. No picture, no sound, nothing recorded of any person. That is why it is allowed where a camera is not.
✓Every door open has a time on it. Two sensors for the front door and the terrace or the store room. The log is on your phone.
✓No monthly fee, ever. No contract, no control room. The hardware is yours.
✓Nothing wired. The presence sensor takes a USB supply. The door sensors stick on.
✓14 days to change your mind. Sold and shipped by Shelly, the manufacturer.
The sensor does not count people and nothing lawful will; it tells you a room is in use and when.
What buyers actually say
4.1★★★★★across 43 reviews of the three products on the manufacturer's own store, pulled as written
★★★★★
"The Presence Gen 4 is fast and accurate, the interface is convenient."
J.M.D. on Shelly Presence Gen4 Verified
★★★★★
"It is very responsive and tracks all objects perfectly. The temperature is a little "warm" during use, but not excessive. I'm using 3 of them in my home, and they are perfectly integrated into HA. Very Good."
F. on Shelly Presence Gen4 Verified
★★★★★
"The best presence senzor U can get. Until now."
D.I. on Shelly Presence Gen4 Verified
★★★★☆
"After one month of use, I can say that the LOQED lock works consistently and reliably. However, the interior handle could be improved: there should be a little more space between the handle and the main LOQED unit, and the handle itself could be longer and shaped more ergonomically to fit the hand better. The display is also rather dim, and the text is not always easy to read through the dark cover. I would appreciate alternative handle designs being offered as accessories."
S. on LOQED Touch Smart Lock 2S Verified
★★★★★
"Easy setup and works reliably"
M.E. on Shelly BLU Door/Window ZB Verified
★★★★★
"Works as advertised"
K.P. on Shelly BLU Door/Window ZB Verified
The door sensor has a mixed record: several buyers report slow or unreliable updates, and support suggests a firmware update. The lock's reviewers want a fully touch-sensitive screen. The full, unfiltered reviews are on the manufacturer's store.
Questions before you buy
Does the sensor count how many people are inside?
No, and nothing lawful will. It tells you a room is in use and when. If a booking said two and the place was in use from eleven at night to four in the morning, that is what you know. Who and how many is not in the record.
Am I allowed a presence sensor when I am not allowed a camera?
They are different things in law. A camera records an identifiable person. This records that a room was in use, with a time. No picture, no sound. Declare it in the listing and the house rules all the same.
Will the lock fit my door?
It mounts over the euro cylinder that almost every European door uses. Check yours before you order. If it is different, a locksmith swaps the cylinder in under an hour.
Is the lock in the kit?
No. The kit is the presence sensor and two door sensors, 86.45 EUR. The LOQED smart lock is offered on the next page, below its shop price, for anyone who wants the key question answered too.
Is there a monthly fee?
No fee, no contract, no account you have to keep paying for. The hardware is yours.
How hard is the setup?
The presence sensor takes a USB supply. The door sensors stick on, and the app walks you through adding them. If you add the lock, it mounts over the euro cylinder. None of it needs a trade.
Sources. Indoor camera prohibition: Airbnb policy effective 30 April 2024. GDPR household exemption and its limits for let property: EU data protection guidance and legal commentary on tourist and residential accommodation. Cost of copying a key and of a locksmith changing a euro cylinder: published European locksmith and hardware price guides, 2025 to 2026. Monitored alarm subscription pricing: published monthly plans from European alarm providers. Prices: shelly.com, 2 September 2026.
Published by Shelly Europe. This page is a paid promotion published on behalf of Shelly Europe, and the publisher earns from purchases made through the links on it. Prices are from the manufacturer's store and were correct at the time of writing. Nothing here is legal or insurance advice; policy terms, building regulations and platform rules differ by country and change over time.
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