Requirements for Standardised Representation of Public Law Restrictions based on LADM

Legal relations applying to land are of significant importance for land administration. Such relations include Rights, Restrictions and Responsibilities, deriving both from Private and Public Law. However, only the former are normally registered within cadastral systems, while the latter are either not required to be registered, or are registered to individual, thematic registries. Restrictions deriving from Public Law are gradually increasing in number and complexity, and impose significant impacts on land management, thus introducing the need of systematically organising and registering them. Standardisation is considered a means of fulfilling this aim, as it provides a common framework within which, consensus among different stakeholders on a specific process or product is achieved. Within the field of land administration, the international Land Administration Domain Model (LADM) standard plays predominant role in standardising legal relations between beneficiaries and land parcels. Therefore, this paper aims to investigate the integration of Public Law Restrictions’ (PLRs) requirements, within the LADM context. As a first step, the PLRs are recognised and classified. Next, in relation to modelling based on LADM concept, three approaches are considered: 1. within the Administrative Package by adding subclasses for PLRs to the LA_Restriction class, 2. within the SpatialUnit Package by adding new specialisations and subclasses to the LA_SpatialUnit class (also extending the code list LA_RestrictionType with PLR types) and 3. again within the SpatialUnit Package, but by using the “level” concept of LADM and the class LA_Level (also extending the code list LA_RestrictionType). The different modelling approaches are identified and presented considering modelling efficiency, UML models’ complexity and extensibility, while the proposed modelling approach can be considered for further extending and refining the current LADM legal concept, to include PLRs in the context of its revision. After initial considerations, such as model clarity, completeness, but also model simplicity, the authors opted for the third approach, as the one that best fits the purpose of PLR standardisation, which is then further analysed in more detail. Challenges regarding standardisation of PLRs within the LADM context, are also addressed, with regards to the on-going LADM revision process.