you need to make sure that you are prepared to have all the legal work done this means you will need to make each new plot of land with there own escaritura (deeds) you also have to make sure each plot of land has access to the road seperatly so this to has to be done. once you can get this done paperwork then i would imagine you can build seperatly on each one as well but you will have to make sure your land is urbano not agricultural land if it is  agricultural land then a max of 60sq mts can be built for a purpose of non dewling livestock or feed can be stored there check that out