Before you even begin your search it is beneficial to have some background knowledge of the different types of land you will find on offer in Spain. Broadly these can be divided into urban and rustic land. There are important distinctions between urban and rustic land in Spain. You can always construct on urban land and on rustic land there will be some form of restriction that you will need to abide by. There are also regional differences to be aware of and local town halls can apply rules differently. This is one of the reasons why it is so important to access local knowledge from a trained professional.
Urban land (suelo urbano) is usually located in areas that have already been built upon such as cities, towns and villages. It is not necessarily a built-up area, however, and it will be marked out on the Plan General de Ordenación Urbana. This type of land is likely to be connected to mains services already although there may still be some connection requirements to complete. There is a minimum amount of land you must buy when it is classified as urban, and is determined by the town hall. The amount you purchase will determine the size of the house you can build.
You are allowed to build on rustic land (suelo rústico also known as a type of suelo no urbanizable) if you meet certain requirements relating to the proportion of the land to be built on. You are likely to need to buy a substantial plot if you wish to build on it. However, the good news is that you needn’t worry about the price. Rustic land is much cheaper to purchase than urban land. Different town halls will have different expectations and ultimately it is their decision about where you can and cannot build. There are degrees of protection afforded to rustic land. For example, land in or around a national park or flood area. If this applies to the plot of land you have in mind, your solicitor will need to check carefully what the situation is and whether it is wise or not to buy.
Suelo urbanizable is a category of land which is neither urban nor rustic and cannot be built on until there is an urban development plan. It is likely to have all the services already in place and you need only apply for detailed planning permission from the local town hall. If any services are outstanding from the plot then you should check how much it will cost to have them installed. Although the land is within the jurisdiction of the local town hall there are also rules and regulations that apply to it as a result of national and regional legislation. Your solicitor must check these out carefully to make sure you comply.