Intense exploitation of land implies the development of multi-level, multi-purpose, overlap-ping and interlocking structures on 3D space, thus resulting in complex, stratified, 3D real property rights between individual owners, as well as restrictions. Legislation regulates the ownership status and use of land by imposing restrictions known as Public Law Restrictions (PLRs). PLRs extend to various fields and various legislative frameworks, such as the protection of archaeological sites, protection and maintenance of underground infrastructures and utilities, environmental protection, flying of unmanned air vehicles, etc. PLRs are usually investigated in the context of property rights and restrictions in the various Land Administration Systems worldwide, and do not often gain specific attention. However, it is noticed that the restrictions that arise from Public Law need to be investigated and classified, so that they can be better utilised in the property status of land ownership. This review paper investigates the legal statutes on PLRs within the context of 3D land administration and the stipulations used to provide unambiguous modelling of PLRs, as provided by the relative literature. Moreover, the PLRs applied in the 3D space, to clearly depict rights, restrictions and responsibilities on the relevant spatial unit (land, air, marine parcel, mine, utility network, etc.), are particularly examined. Therefore, this work is to critically review and assess the aforementioned approaches on PLRs’ registration, modelling and organisation, as provided by a literature survey, and provides an overall view of the requirements and challenges within the development of 3D Land Administration Systems also considering standardisation developments.@en

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.@en

Intense exploitation of land in the vertical direction has brought up complex legal relations between different types of spatial units with various characteristics (e.g., land, marine, air, underground parcels, and infrastructure objects). Therefore, the use of 3D models is required to clearly represent real property and associated Rights, Restrictions and Responsibilities (RRRs), deriving both from Private and Public Law. The latter are either not registered to cadastral systems (i.e., in The Netherlands very few have been registered like the private natural beauty areas, as they came with tax benefits), or are recorded to individual, thematic registries. Public Law Restrictions (PLRs) impose significant impact on ownership rights and land management, thus requiring to be systematically organized and registered. This brings out issues of identifying which types of PLRs need to be registered (based on land administration policies that apply in each country/ jurisdiction), selecting and “spatializing” them (in 2D/3D/nD). Within the field of land administration, the ISO 19152:2012 Land Administration Domain Model (LADM) plays predominant role in standardizing legal relations between parties (people) and spatial units (land). LADM is currently under revision with its second edition widening its scope as a multipart standard comprising 6 Parts. The revision of LADM stimulates discussion on new concepts that could be included at the Edition II, and possibilities of refining the existing ones. In this context, the paper investigates the option to model PLRs into the multipart standard and investigates how to optimally categorize them based on the LADM Edition II Parts. The paper builds on previous work by the authors and aims to propose a flexible framework to model PLRs at conceptual level in the context of LADM Edition II. To validate the modelling proposal, two case studies of PLRs are studied. The first one relates to the restrictions imposed on land parcels crossed by the Trans Adriatic Pipeline (TAP) in Northern Greece, and they refer to the establishment of protection zones, where construction and agricultural restrictions apply. The second case study refers to land use restrictions in the vicinity of an archaeological site in the municipality of Patras, in southern Greece. Those use cases were selected because of their generic character that may apply to other countries/ jurisdictions, regardless of legal framework differences.@en

Among the topics that are introduced and/ or being refined in the context of the revision of the LADM 19152:2012, the legal Land Administration-related aspects are being investigated. With the knowledge and the experience from the developments of the LADM so far, and the ongoing discussion between the parties involved in the standardisation process, the need to clarify certain legal land-related aspects and to examine the alternatives for further refinement is highlighted. Therefore, this paper presents prior work on LADM-related legal aspects since the vote of LADM as ISO standard (2012), till the time of the preparation of this paper (2021) to report the necessary background for this research. This concerns the developments related to the various legal refinements that have been proposed during this time period and specifically the refinement of the legal profiles, the LADM functional support to representation of both statutory and customary tenure and the work regarding the explicit definition of restrictions that arise from Public Law. Moreover, this paper focuses on documenting the proposals on a refined legal model for the LADM Edition II. These include the following: (a) more detailed classification of RRRs, based on the two major types of interests in land: privately agreed interests as well as regulations imposed by a public agency and Public Law restrictions. The paper also includes (b) a discussion on the extent that LADM Edition I provides efficient support for the title and deed registration systems (as others e.g. in socialist environment), as well as (c) a discussion on how restrictions and responsibilities can be modelled as rights’ relationships between an owning and a benefitting Party. @en

Rapid urbanisation relates to increased space requirements above and below ground and the development of complex structures. This profound need attracted increasing interest for the collection, modelling, management, visualisation and dissemination of 3D objects through various application fields, such as: 3D Cadastre, 3D City Modelling and Building Information Modelling. Contemporary advances in GIS technology, Geo-Web services and computer graphics facilitate the development of such models accompanied by semantic, geometrical and topological information, while the use of international standards enables the communication and interoperability between the systems. The aim of this paper is to combine state-of-the art methodologies and technologies for the development of semantically enriched 3D models for the Campus of the National Technical University of Athens in Greece. The result is a web-based 3D Campus map that integrates these models as Web Services, providing access to management and navigation for the campus area and can also be used for maintenance purposes from the various NTUA Departments. To this end, the database schema has been designed compatible with CityGML, while attention was given to interoperability issues that arise from differently derived 3D models which had to be stored and visualised while retaining their characteristics.@en

Rapid urbanisation relates to increased space requirements above and below ground and the development of complex structures. This profound need attracted increasing interest for the collection, modelling, management, visualisation and dissemination of 3D objects through various application fields, such as: 3D Cadastre, 3D City Modelling and Building Information Modelling. Contemporary advances in GIS technology, Geo-Web services and computer graphics facilitate the development of such models accompanied by semantic, geometrical and topological information, while the use of international standards enables the communication and interoperability between the systems. The aim of this paper is to combine state-of-the art methodologies and technologies for the development of semantically enriched 3D models for the Campus of the National Technical University of Athens in Greece. The result is a web-based 3D Campus map that integrates these models as Web Services, providing access to management and navigation for the campus area and can also be used for maintenance purposes from the various NTUA Departments. To this end, the database schema has been designed compatible with CityGML, while attention was given to interoperability issues that arise from differently derived 3D models which had to be stored and visualised while retaining their characteristics.@en