The responsibility for any illegal building done by a former owner. Buying property in Mallorca

The Act of Urbanism of Balear Islands did upgrade the responsibility of illegals works done in your property.

In some cases you may be also responsible of ilegal works done by former owner. 
In those cases the right of the administration to order the demolition has not expired, (note properties build on protected area right of administration will NEVER prescribe). So YOU MAY have to demolish the ilegal part and also pay the costs.

So am I 100% save if the right of the administration to order the demolition has expired.?

NO. If you apply for any license to rebuild/repair the property, license will never be grated.

-Property Registry description matches with reality.

Mean nothing. To be registered does not mean that it is legal. The only way to be sure of the legality it’s with the original building license or /and old aerial pictures 

-I got a certificate stating that there are NO FILES CONCERNING INFRINGEMENTS OF URBAN PLANNING. 

That means Town Hall hd never open a file. But infraction may be there. If you build a property without license and town hall architect never goes there will not be a file… but you property it’s 100% illegal.

-Infractions are not in town?

Yes Infractions are also found in urban areas.

So, if you are not 100% sure it’s legal, or you are not sure you can live with the consequences of the illegality, don’t buy it