After the Granada earthquake: how drones are changing building damage assessment

In the night of Saturday 15 August, a magnitude 5 earthquake shook the province of Granada. According to Spain's Instituto Geográfico Nacional the epicentre was at Alhendín, south of the provincial capital; preliminary readings place the focus close to the surface. The quake was felt as far away as Seville and Madrid, and across large parts of the Costa del Sol.

According to the Andalusian regional government nobody was injured. The balance of the first hours was still substantial: more than 200 emergency calls to 112, around one hundred fire brigade call-outs in Granada, and several people who had to be freed from stalled lifts. The most frequent reports concerned cracked façades, fallen façade elements and debris on pavements.

The Junta de Andalucía activated level 1 of its earthquake emergency plan and mobilised a group of architects to assess building damage. This is the phase that follows every earthquake and rarely makes headlines: the systematic inspection of many hundreds of buildings for damage that cannot be seen from the street.

The problem after the quake: seeing without taking risks

A quake of this size rarely leaves collapsed houses, but it leaves a great many open questions. Is the crack in the façade superficial or structural? Has something come loose on the roof that will fall in the next gust of wind? This is exactly what the authorities warn about after such events: cornices, balconies and wall copings from which parts can detach.

The traditional answer to these questions is laborious. Scaffolding or a lifting platform, closed pavements and a surveyor working along every façade individually. For a single building that is feasible. For hundreds of affected properties across several municipalities it becomes a bottleneck, and every day of waiting is a day of uncertainty for owners and residents.

What the drone contributes in this situation

Drone-based building damage analysis addresses precisely this bottleneck. An enterprise platform such as the FANTM 4TD captures a multi-storey building completely within minutes, with nobody stepping onto a roof and no scaffolding required.

• Detail imagery from a safe distance: the tele camera with up to 112x hybrid zoom reveals hairline cracks, loosened tiles and damaged junctions while the aircraft stays well away from the building. Nobody has to stand beneath a potentially loose façade.
• Radiometric thermography: fresh cracks often let moisture in long before a stain becomes visible indoors. The thermal camera maps such moisture zones and thermal bridges across the whole surface, and every pixel carries a temperature value.
• Geo-referenced documentation: RTK-supported imagery with a positional accuracy of around three centimetres locates every damage point precisely on the building. Combined with the timestamp, the result is an audit-proof image series that still stands weeks later.
• Comparability over time: if the same route is flown again later, it can be demonstrated whether a crack is moving or stable. That question frequently decides the scope and cost of repairs.

After an earthquake the decisive image is not the most beautiful one but the most defensible one: with measurement, position and timestamp, captured before anything is repaired, replastered or disputed.

For insurers and property managers: the question of proof

For insurance brokers and loss adjusters, time is the decisive factor. Damage documented only weeks later is open to challenge: was the crack already there? Does the damage really stem from the quake? A promptly flown, geo-referenced image series per property answers these questions before they are asked.

Property managers and owner communities face a different task after such an event: many buildings, little time and a limited budget. A single flight day can capture several properties of a portfolio and delivers a prioritised condition report per building, as the basis for deciding where action is needed first.

What the drone does not replace

As clear as the benefit is, so is the limit: assessing structural safety remains the task of architects, structural engineers and the competent authorities. In Granada this is being handled by the group of architects activated by the regional government. The drone does not replace that judgement. It supplies the data basis for it: faster, more complete and without risk to the people doing the assessing.

The Granada quake was clearly felt along the Costa del Sol too, from Estepona via Fuengirola to Nerja. For owners, managers and agents in the region it is a good moment to have the current condition of their buildings documented, before the next event raises the question of what things looked like beforehand.

Event details according to the Instituto Geográfico Nacional (IGN) and the Junta de Andalucía, as at 16 August 2026.