The specific requirements to access a PhD programme are decided by the University itself and the department to which it belongs. In some Universities this oppotunity to write a Doctoral Thesis is simple, and in others, due to the programme´s prestige and the number of applicants, it is much more difficult.
Official Postgraduate Degrees are normally necessary to join PhD programmes in the Spanish education system, since they help to generate ideas and contents to be later developed during the PhD. Current Spanish regulation, in most cases, does not recognise credits obtained in an University-specific Master as valid to enrol a PhD programme. Therefore, an University-specific Postgraduate Degree, in general, does not provide access to the PhD.
However, there are exceptions in which an University-specific Master does provide such access. This is the case of MCH, thanks to an agreement that has been reached with the DPA of ETSAM, UPM. MCH graduates are allowed to access the DPA PhD program, thanks to the teaching quality and scientific content of the master, proved over twelve editions and widely recognized internationally.
Further details about that MCH agreement can be found here.