One of the main problems of the inventory of architectural heritage is managing and storing large amounts of information in different formats, in addition to the need to organize and manage the information generated by collaborative work between the different technicians who participate in the documentation process. The solution involves the development of a model capable of incorporating information on a layered support and allowing analysis and management, as well as interoperability between tools and other systems throughout the entire life cycle of the building. To carry out this work, two methodologies have been selected to verify their effectiveness in the field of architectural heritage inventory, covering the specific needs of generating a complete graphic database of the building. The Arches platform, a free open source software developed to carry out inventories, has been chosen for its interoperability, specificity and all the characteristics and functions described above. In turn, a WebGIS has been developed using free software standards and technology, to examine the possibilities it offers in relation to specific inventory programs. As a result, the creation of an Information System of the Mudejar Architectural Heritage of Aragón has been proposed, with the purpose of integrating under a common support, all the documentation and graphic information available on the heritage asset. The research limitations are the creation of a geo-referenced database, with geometric information on each building, which addresses the cataloguing of more than 200 assets, due to the uniqueness of this architectural style. The information is stored complying with the documentation standards to ensure interoperability and accessibility to the data.