cave houses in SpainCave houses have provided low cost housing for farm workers in Spain for centuries. Nowadays they are still proving to be a sound investment and make for quite a unique place to live. As well as being easy to extend should you need another room, the temperature inside is kept between 18-20ºC all year round.

But when advising a client buying a traditional cave house in Spain, what criteria does a surveyor need to consider? Is some kind of geological inspection a requirement before a survey can be passed and therefore a mortgage granted?

According to Campbell D. Ferguson from Survey Spain Network of Chartered Surveyors, when looking at a cave house the principal concern would be damp, both from rainwater percolating through the rock and also from condensation due to poor ventilation.

Both of these can be dealt with easily by appropriate drainage channels along the inside of the cave, perhaps behind a false wall or seating arrangement. Similarly, piping for services and ventilation would have to be allowed for and hidden. Externally, these services would have to come from and go somewhere, so make sure that they are connected to legal, reliable supplies/drains.

Yes, the geology is important, as that will dictate the amount of water percolation and possible cracking/landslip potential. Check the older, neighbouring properties for what’s happened to them. The CEE – Certificado de Eficiencia Energética will certainly be interesting and could give an exceptionally good rating!

The legality issue must have been addressed in the past, with the ownership being like an apartment, as the landowner of the surface ground above in theory owns a cone based on the land boundary and from ‘the centre of the earth to the sky’.

Who knows, there may be gold underground!

Originally published on Tumbit Spain, the website for all legal, financial and procedural information.