Security · Costa del Sol

How to Protect an Empty House When You're Away

If you own a second home on the Costa del Sol — in Marbella, Estepona, Fuengirola, or one of the surrounding towns — chances are it sits empty for weeks or months at a time. That gap is exactly what organised burglary gangs look for: they don't just pick a door at random, they first work out which houses are genuinely unoccupied. Here's the method they've been using, what Spanish police officially recommend, and what technology can realistically do while you're not there.

Rodion Tulba Rodion Tulba Technical Director · 350+ installations

Part of the Costa del Sol security guide

The trick gangs use to mark empty houses: a thread on the door frame

A method that keeps showing up in recent police operations: a thin thread, a bead of silicone, or a piece of tape stuck between the door and its frame, at a discreet height. If it's still there days later, undisturbed, it tells whoever placed it that nobody has opened that door — the house is empty. It's a cheap way to "watch" an entire street without ever getting close or taking a risk.

This isn't theoretical. Spain's Policía Nacional and Guardia Civil have dismantled gangs using exactly this method: in Elche (Alicante) in November 2025, in Tarazona in May 2026, and in Seville in July 2026, where they had already marked 11 homes in the same area before being caught.

If you spot a thread, a silicone dot, or tape on your door — or a neighbour's:

  • Don't remove it yourself. It could tip off whoever placed it, or destroy evidence police can use.
  • Call the Policía Nacional (091) or Guardia Civil (062) and tell them exactly where and how you found it.
  • Check your neighbours' door frames too. These gangs typically mark several houses on the same street or urbanisation, not just one.

What Spanish police officially advise before you travel

The Policía Nacional keeps repeating a few simple rules that a surprising number of second-home owners still skip:

  • Don't lower your blinds all the way. Fully shut blinds for weeks is one of the clearest signals that nobody's home.
  • Use light timers so different rooms switch on and off at normal times.
  • Be discreet on social media. Posting live from the airport, or tagging your own house while you're gone, tells anyone watching exactly when the coast is clear.
  • If you come back and the door's been forced, don't go in. Call 091 and wait outside — whoever broke in may still be inside.
  • Police also recommend anti-bumping locks and an armoured door shield as the first physical barrier, before any electronic system.

Why the Costa del Sol specifically is a target

It's not just a feeling — the numbers back it up. According to a private study by LPA (Leading Property Agents of Spain), 44% of homes in Marbella are second residences — nearly half the town's housing stock sits empty for part of the year, which is exactly why it draws this kind of gang activity.

The other side of the picture: according to 2025 Ministry of Interior figures, burglaries in homes in Málaga province dropped to 2,408 cases, down 23.9% versus 2024. That's genuinely good news, but read it with the right nuance — these are reported crimes (not everything gets reported), and even with the drop, the province still sees more than 6 home burglaries a day.

What technology can actually do while you're away

None of this replaces the common-sense steps above — it reinforces them:

  • Cameras you can check from your phone, so you can look in on your house from anywhere.
  • Ajax alarms with no monthly fees, sending alerts straight to your phone if it detects movement or a forced door or window.
  • Motion detection covering the perimeter and access points, not just inside the house.
  • A video doorbell, so you can see who's at the door even when you're a thousand kilometres away.

At Dartel Solutions we sell and install this kind of system across the Costa del Sol: you buy the equipment, we do the fitting and setup, no need to understand wiring or apps yourself. We've completed more than 350 installations and we support customers in Spanish, English, Russian, and Ukrainian. For a house that sits empty for months we add a 5 MP turret camera you can check from your phone and an alarm kit with dual 4G SIM, which keeps alerting you even if the fibre is cut.

Frequently asked questions

What should I do if I find a thread or mark on my door frame?

Don't touch it. Call the Policía Nacional (091) or Guardia Civil (062), and check whether your neighbours have the same mark.

Is it safe to post my holidays on social media?

It's safer to post once you're back, or at least avoid tagging your house or announcing live that you'll be away for weeks.

What should I do if I come home and the door's been forced?

Don't go in. Call 091 from outside and wait for the police to arrive.

Is an alarm with cameras enough for a house left empty for months?

It's the strongest base you can build, combined with the basics — blinds, timers, discretion. If you'd like, we can also sign a confidentiality agreement on the installation project, on request.

Ready to secure your house before your next trip?

Message us on WhatsApp at +34 672 81 57 89 or email info@dartelsolutions.com for a no-obligation quote.

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Sources: Policía Nacional and Guardia Civil operations reported by Euronews (Nov 2025), Aragón Digital (May 2026) and Andalucía Información (Jul 2026); official Policía Nacional travel advice; LPA (Leading Property Agents of Spain) study on second homes in Marbella; Spanish Ministry of the Interior crime figures 2025 (reported crimes).

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