The design process is perhaps the most important part of any building project. If mistakes are made at this stage then the costs can escalate out of control during the construction stage later on. Planning authourities have strict requirements and these will differ depending on the location and region.
Cost budgets must always be taken into account during the design process and careful consideration must be given to specific design details that can seem attractive at first sight but may prove to be expensive at a later point in the construction contract.
During the construction period there are many matters to consider including the design process on site as well as the administrative documentation including builder/constructor contracts and insurance which is essential in Spain.