The PTP (Territorial Planning Plan) for the Gernika-Markina Functional Area is a regulatory instrument for land use planning that implements the Basque Country's Land Use Planning Guidelines. It covers 29 municipalities in Busturialdea and Lea-Artibai. The plan defines a sustainable territorial model with a 16-year time horizon and indefinite validity, which must be respected by municipal plans and sectoral territorial plans. It establishes objectives such as maintaining the population, concentrating residential space, promoting economic development and productive land, preserving natural, landscape, and cultural values, sustainable mobility and intermodality in transport, the use of renewable energies, the regeneration of degraded spaces, and the conservation of historical, cultural, and architectural heritage as a tourist asset. The PTP also regulates the management of the physical environment, establishing protection categories (Urdaibai, Gaztelugatxe, Natura 2000 Network, Oiz Massif, etc.) and guidelines for residential settlements, infrastructure, facilities, and services.