What happens if someone builds on another person's land?

Question

José Manuel Alburquerque · Accepted Answer

In principle, whatever has been built belongs to the owner of the land, by virtue of what the law calls accession (“accesión”). But if the builder acted in good faith, reasonably believing that they were entitled to do so, the owner cannot keep the construction without paying for it and, if the construction is worth more than the land encroached upon, may have to sell that land to the builder. If the builder acted in bad faith, they lose what they built and must pay compensation for the damage. In that case, if they only encroached on part of the property, the owner can also require them to demolish what they built on it. Anyone who sees someone building on their land should object straight away and in writing, because their objection puts an end to the builder's good faith. If the builder acted in good faith Under the “Código Civil de Cataluña”, the Catalan Civil Code, a person acts in good faith if they reasonably believe that they are entitled to build, for example because they thought the land was theirs or made a mistake about the boundary. Good faith is presumed, but it ends as soon as the owner of the land objects. What happens next depends on which is worth more, the land encroached upon or the construction together with the builder's own land on which it stands, if there is any: If the land is worth more than the construction, the owner can choose between keeping the construction, paying what it cost to build and, if it also occupies land belonging to the builder, the value of that land, or making the builder buy the land occupied. If the land cannot be divided or what remains cannot be built on, the owner can make the builder buy the whole plot. In both cases the owner is also entitled to compensation for the damage. The owner has three years from the completion of the work in which to choose. After that, they can only require the builder to buy the land. If the construction encroaches on only part of the property and the portion encroached upon is not worth more than the construction, as happens with a neighbour's house that extends a few metres into the land next door, the owner has to transfer that portion to the builder if the builder pays its value and compensation for the damage, provided that the building cannot be divided. If the portion cannot be separated or what the owner has left cannot be built on, the owner can require the builder to buy the whole plot. If there is or could be a condominium (“propiedad horizontal”), the owner can ask to be paid in flats or commercial premises instead of money. Under the Spanish Civil Code (“Código civil”), which applies in most of the rest of Spain, the owner can keep a construction built in good faith by paying the compensation laid down by law, or make the builder pay for the land, with no time limit for choosing. Construction that partly encroaches on the neighbouring property is not regulated in that code. The courts resolve such cases with similar rules. If the builder acted in bad faith A person acts in bad faith if they know that the land is not theirs or carry on building after the owner has objected. In that case they lose everything they have built to the owner of the land. In addition, they must compensate the owner for the damage. If the construction encroaches on only part of the property, the owner can require the builder to demolish, at the builder's own expense, what has been built on the owner's land, in addition to the compensation. The owner can also choose the solutions provided for good faith, if they suit them better. The court may refuse demolition if it would cause the builder disproportionate harm. What you should do If you see that someone is building on your land, object as soon as possible in a way that leaves a record, for example with a “burofax”, a certified letter with proof of content, or a formal demand served through a notary. From that moment on, the builder is no longer acting in good faith and, if they carry on, they build at their own risk. If the work is under way, you can ask the court to stop it. Before suing, you must, in general, attempt to reach an agreement, for example with a written proposal or mediation. If the construction was carried out in good faith and the land is worth more, do not let the three years you have to choose go by. What the town council may do if the construction has no building permit is a separate matter, with its own time limits.