Today, population growth, high urbanization rates, and global agenda issues have led to the intensive use of land and air and water spaces, and cadastral systems that manage the people–land relationship have evolved into a multi-purpose form that supports various land-based activities. This situation has necessitated the modernization of traditional land administration and cadastral systems to manage the people–land relationship effectively. This study conducts a literature review on current cadastral trends emerging from the perspective of modern land administration systems (LASs). A total of 367 studies published in the Web of Science (WoS) database in the last decade on 3D cadastre, technical infrastructure cadastre, maritime cadastre, public law restriction (PLR) cadastre, fit-for-purpose land management, and disaster-sensitive cadastral trends are analyzed. The study aims to analyze the interest of the land administration community in current cadastral trends and present the results. The analysis results show that the most researched trend is 3D cadastre, and the least researched trends are PLRs cadastre and disaster-responsive cadastre. LADM stands out as a widely used framework across the studies.@en

Over the past decade, numerous countries and researchers have been investigating the potential of 3D cadastre based on the Building Information Model (BIM). In Türkiye, the General Directorate of Land Registry and Cadastre (GDLRC) has been engaged in the “Production of 3D City Models and Creation of 3D Cadastral Bases Project” since 2018. One of the objectives is to develop 3D (physical) digital building models (and databases) through the digitization of floor plans of architectural drawings. In order to ensure the long-term viability of this project, a new regulation was issued in 2021. This regulation mandates the submission of 3D digital building models to the land registry in order to register condominiums. The future goals of the GDLRC include utilizing the 3D digital building models produced to create legal spaces in condominium buildings for the 3D cadastre. However, no research has yet been carried out for this goal. The objective of this research is to identify the legal and BIM data requirements for deriving legal spaces in condominium buildings, in light of the legislative analysis, and to develop a web-based 3D cadastre visualization prototype (showing both legal spaces and physical objects) based on the requirements obtained from the scientific literature. The result of this research demonstrates that well-structured and annotated BIM data can be used to develop a 3D cadastre prototype that meets the legal requirements in the case of Türkiye. Moreover, it is evident that, although the GDLRC has initiated the construction of a robust foundation for a 3D cadastre based on BIM, further enhancements and resolutions must be implemented from a legal and technical standpoint. It is postulated that the identified requirements and the proposed methodology in this research may assist decision-makers in Türkiye and globally in formulating their strategic plans for a 3D cadastre.@en

The boundary of real property is the fundamental element for securing rights attached to land. Countries, even with a long-standing cadastral tradition, often face the challenge of interpreting the course of a parcel boundary on the ground based on the available evidence, as data quality is very heterogeneous. Various cadastral principles and procedures have been developed for the determination of parcel boundaries in the field, which may also be associated with resolving boundary disputes. This article documents and compares the principles and procedures applied in the determination of property boundaries in selected civil law countries based on a novel conceptual model developed for that purpose. The notion of ‘boundary determination’ used in this article refers to demarcating and surveying land parcel boundaries during the initial cadastral survey and cadastral update procedures. The selected countries include Denmark and Sweden, which apply Nordic civil law; Slovenia and Turkey, which apply German civil law; and Spain, which applies Napoleonic civil law. The demarcation principles and processes applied in the different cadastral systems, the parties involved, and the evidence taken into consideration in these processes are described and compared. The main aim is to contribute to the documentation of the reasoning applied to the property boundary determination in the selected civil law countries.

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A code list in Unified Modeling Language (UML), a simple list of values without any structure, can be employed as a simple data type to further capture the semantics of a domain. The code list values as used in international standards (e.g. ISO and OGC) are generally presented without definition, reference to the source of a definition, multi-lingual alternative term support and semantic relationships (e.g. hierarchical, associative). Moreover, managing, implementing, and maintaining UML code lists can be considered as a difficult task since they generally do not provide structured and semantically enriched values. This is also true in the case of ISO 19152:2012 Land Administration Domain Model (LADM), which is currently under systematic review and adding more content, meaning and structure to code list values could be considered an improvement. In last decade, there is a growing interest in representing terms as well as code list values using Semantic Web technologies (e.g. RDF, OWL, SKOS, SPARQL) and making them available on a registry (e.g. ISO/TC211 Geolexica, OGC Definitions Server, INSPIRE code list register, BARTOC), including land administration domain (e.g. CaLAThe, LandVoc). However, there is no joint understanding in structuring, extending and maintaining code list values, which may be achieved through an agreed metamodel. Such a metamodel should also provide insight into content, localisation (multi-lingual support), versioning and implementation. The aim of this study is to propose a framework (basically a metamodel) for structuring, extending, maintaining and implementing semantically enriched code lists, and to discuss the application of the proposed framework to be included in the revision of LADM. To achieve this aim, the requirements for refined code list values are firstly collected considering existing thesauri, vocabularies and standards. Subsequently, a metamodel is proposed for the refined code list. The proposed metamodel is applied to a code list of LADM as well as a part of a selected country profile.@en

Spatial data in a Land Administration (LA) establish a fundamental geospatial data theme (see UN GGIM, 2018) and the integrated geospatial information framework for any Spatial Data Infrastructure (SDI). Domain-specific standards, an integral component of the SDI, play an essential role to represent the semantics of domains, specify links between distributed registries and databases, and stimulate the development and implementation for Land Administration Systems (LAS). As an international descriptive standard providing an abstract conceptual schema, the ISO 19152:2012 Land Administration Domain Model (LADM) has been used and is being used as a reference for the implementation of LAS. Various approaches have been used for the LADM implementation that includes elaborating (via a country profile) and realizing a technical model suitable for the implementation (van Oosterom and Lemmen, 2015). LADM focuses on a specific function of LA that is interested in Rights, Responsibilities and Restrictions (RRR) affecting land, and the geometrical components thereof. The land value function of LA is considered outside the scope in the first edition. Recently, for extending the flexible and modular basis of the LADM, a valuation information model is developed for the specification of valuation information maintained by public authorities. It identifies the links between property valuation and the other LA registries and databases (e.g., cadastre, land registry, building and dwelling registries) that may enable interoperability across systems. The conceptual schema of the model provides a common basis to direct the development of local and national valuation databases and information technology products and services, following an approach similar to the LADM implementation. The proposed LADM Valuation Information Model is on the agenda of the development of the second edition of LADM within ISO/TC211. The operability of the newly proposed conceptual model needs to be evaluated through technical implementation. This paper describes the development of a prototype for the implementation of the LADM Valuation Information Model and assesses its operability through a case study for Turkey. The primary aim of the paper is to test the capabilities of the LADM Valuation Information Model using the required and produced data in recurrent valuation processes, but not to build a specific information management system for Turkey. As the implementation of a LADM compliant prototype initially requires the development of a country profile at conceptual level, methodologies applied for LADM profile development are examined and then a Turkish LADM Valuation Information Model country profile is proposed using the Conceptual Schema Languages (CSL) of the Unified Modelling Language (UML) and INTERLIS. INTERLIS is a formal language as well as a set of software tools that support LADM implementations. Subsequently, approaches and tools used in the LADM implementation are investigated and utilized for the automated transformations from the country profile to several technical models. In this context, the article presents the experiences gained during the implementations. Moreover, strategies for implementing and managing property valuation information more efficiently (e.g. bi-temporal aspects of valuation information management) are also studied and applied to the implementation. The generated technical models are then populated with sample datasets related to recurrent property valuation including the geometries of valuation units, as well as valuation information covering several years. The developed prototype is then tested through a number of queries to assess whether the LADM Valuation Information Model fulfils information management needs of recurrent valuations. The main contribution of this paper is to provide a holistic approach on how to develop an LADM conformant prototype for managing property valuation information.

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Condominium is a special and relatively new type of property right emerged in the last century to be a remedy for the management problems in multi-unit buildings. There are many types of condominium regimes, as described in EUI (2005), UNECE (2005) and van der Merwe (2016). The common elements include: (a) Individual right to an apartment, (b) co-ownership (joint ownership) of the common property or the whole property, and (c) membership of an incorporated or unincorporated owners' association (van der Merwe, 2015, p. 5). The ownership shares in the common property are here referred to as co-ownership shares; yet, alternative terms include ownership fraction, condominium share, participation quota, share value, and unit entitlement. Generally, these shares will determine the proportional contribution to the common expenses and the share of common profits, as well as the voting power of each condominium unit owner in the administration of the condominium. The most common approaches to the determination of the co-ownership shares are based on equality, relative size or relative value of each condominium unit, or a combination of such (van der Merwe, 1994, p. 57–58). The literature presents detailed descriptions and comparative analysis related to condominium systems in different jurisdictions (e.g. van der Merwe, 2015; 2016; Paulsson, 2007; EUI, 2005; UNECE, 2005); however, the procedural aspects related to the allotment of co-ownership shares still need to be further investigated. This article aims to describe condominium systems in the Netherlands, Sweden and Turkey, and compare legal provisions and procedures related to the allotment of co-ownership shares in these jurisdictions. The main purpose is to clarify the methodologies behind the determination of the co-ownership shares in national systems to bring new insights to countries, which are trying to revise their national provisions.

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Property valuation is a process that promotes sustainable development as it supports and forms several land management activities. Access to information on the legal, geometric, physical, locational and environmental characteristics of property units together with the economic indicators are required for an effective property valuation system. Traditional cadastral systems generally provide only two-dimensional (2D) legal and geometric information about property units, however, today's valuation practices would benefit significantly from three-dimensional (3D) information in order better to estimate and explain values of property units. The purpose of this paper is to examine how 3D spatial datasets and spatial analyses have been used in property valuation, and to develop 3D valuation unit profile(s) in line with the examination results for the recently proposed Valuation Information Model that extends the ISO 19152:2012 Land Administration Domain Model (LADM) from the valuation point of view. The study focuses more on 3D locational and environmental characteristics of property units; particularly visibility and especially viewshed analysis in terms of property valuation. By using open topography, building and height datasets of the Netherlands, a number of viewshed analyses are conducted to show how it can be utilized using different 3D data sources. The main contribution of the article is to present how 3D datasets and spatial analyses could be used to support property valuation activities and to investigate to what extent it is possible and meaningful to include derived 3D characteristics of property units in valuation registries.

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A recently established joint working group under International Federation of Surveyors (FIG) Commission 9 (Valuation and the Management of Real Estate) and FIG Commission 7 (Cadastre and Land Management) has started the development of an information model for the specification of valuation information maintained by public authorities especially for property taxation. In this initiative, ISO 19152:2012 Land Administration Domain Model (LADM) has been taken as the basis for the development of a Valuation Information Model. A first version of the LADM Valuation Information Model was created based on international standards, literature survey and data gained from questionnaires replied by the national delegates of FIG Commission 9 and FIG Commission 7. The planned further works include (i) creating country profiles, and (ii) development of prototypes for the assessment of country profiles and conceptual model itself. This paper presents an overview of immovable property valuation conducted for taxation purposes in Turkey. Based on this overview, it also proposes a country profile of LADM Valuation Information Model in Turkey case. The country profile covers valuation activities for annually levied recurrent property taxes (i.e. Land Tax and Building Tax) in Turkey, characteristics and spatial aspects of valuation units used in property valuation, property valuation approaches employed for property taxation, transaction prices used in valuation procedures, parties involved in valuation practices, and information on taxes on immovable property. The profile also includes the content of code lists that detail administrative valuations in relation to property tax assessments in Turkey. The proposed profile is evaluated with Unified Modeling Language (UML) instance level diagrams in examples of property taxes on land and building in Turkey for assessing whether the profile fulfills the needs of information management aspects of valuation activities for property taxation. Towards@en

Standardization reduces technical barriers to trade and foster dissemination of innovations. Within the domain of information technology, standardization enhances semantic interoperability of systems and services. In order to achieve the potential of standardization, IT solutions must be localized to adapt to local needs. To reduce localization costs, software developers, but also standards develop and adopt internationalization principles and best practices, cf. the W3C Internationalization (I18n) Activity, the ISO 639 Language Codes, which provides an example for code lists and code list management, and the coding of coordinate reference systems. For the domain of Land Administration, the localization issue extends from language names to the various organizations and institutions dealing with interests in land. Paasch et al (2013) propose code lists as a mean of internationalization by which the classes of the ISO 19152:2012 Land Administration Domain Model (LADM) may be related to the concerned jurisdiction. The issue of code lists has been addressed by the OGC as well, namely in terms of the document 17-050r1 Code List Manifesto by Paul Scarponcini. Motivations for the study include that various OGC standards have encoded enumerations and code lists differently, as realized during the development of the InfraGML standard, which regards land and civil engineering infrastructure facilities, and thus share part of its scope with LADM. Aiming at harmonization of standards within the domain of Land Administration, the present paper proposes a joint management of the code lists which are specified by ISO LADM and by OGC LandInfra / InfraGML, respectively. The FIG motivated the ISO standard LADM and moreover framed research on code lists. It seems therefore appropriate to join with this organization of surveying professionals, also to benefit from sharing of expertise and cost of the management activities. The paper the outlines the tasks of code list management by drawing on the mentioned Code List Manifesto and resuming research supporting code list management, e.g. terminological theory and semantic tools. The setup of a possible code list management system is discussed, and summarized in terms of a draft Memorandum of Understanding.@en

A recently started joint activity under International Federation of Surveyors (FIG) Commission 9 (Valuation and the Management of Real Estate) and FIG Commission 7 (Cadastre and Land Management) has started development of an information model for the specification of valuation information maintained by public authorities especially for property taxation. In this initiative, ISO 19152:2012 Land Administration Domain Model (LADM) has been taken as the basis for the development of a Valuation Information Model. A first version of the LADM Valuation Information Model was created based on standards, literature survey and data gained from questionnaires replied by the national delegates of FIG Commission 9 and FIG Commission 7. The conceptual model was represented through class diagrams of the Unified Modeling Language (UML). This paper describes the development of a prototype for the implementation of the conceptual model in terms of a Turkish case study. The main aim of this paper is to assess and improve the proposed conceptual LADM Valuation Information Model. In the development part, the classes, attributes, constraints, cardinalities and relations between classes of the conceptual model were converted to technical (physical) model, namely the Oracle Spatial 11g database schema has been generated from the conceptual model definitions. The conceptual schema definitions were implemented into the database, which next was loaded with sample datasets related to property valuation and taxation in Turkey. The sample data includes valuation units that are the subjects of recurrently levied property taxes in Turkey, such as unimproved urban parcel and parcel and improvements together as condominium property, valuation and taxation information of the valuation units in different years, and as well as geometries of valuation units. The technical model of LADM Valuation Information Model Turkish Country Profile has been tested in evaluation phase through SQL queries and visualization tools, respectively. In this phase, it is investigated that whether the both conceptual and technical models fulfill the needs of information management aspects of valuation activities for property taxation.@en

Condominium is one of the prevalent forms of three- dimensional (3D) property rights (Paulsson, 2007, p. 32). The condominium concept common to a number of jurisdictions consists of three elements: (a) individual ownership of an apartment, (b) co-ownership (joint ownership) of the land and the common parts of the building, and (c) membership of an incorporated or unincorporated owners' association (van der Merwe, 2015, p. 5). The ownership shares of condominium unit owners in the common property are here referred to as co-ownership shares; yet, alternative terms include ownership fraction, condominium share, participation quota, share value, and unit entitlement. The co-ownership share determines the proportional contribution to the common expenses and the share of common profits, as well as the voting power of each condominium unit owner in the administration of the condominium. The most common approaches to the determination of the co-ownership shares are based on equality, relative size or relative value of each condominium unit, or a combination of such (van der Merwe, 1994, p. 57-58). The literature presents detailed descriptions and comparative analysis related to condominium systems in different jurisdictions (e.g. van der Merwe, 2016; 2015; Paulsson, 2007; EUI, 2005; UNECE, 2005); however, the technical and procedural aspects related to the allotment of co-ownership shares still need to be further investigated. This paper aims to compare methods and procedures applied for the allotment of co-ownership shares of condominium systems in the following seven jurisdictions; Denmark, Germany, South Africa, Sweden, Switzerland, the Netherlands, and Turkey. Also, international geographic information standards (i.e. ISO LADM, OGC LandInfra/InfraGML) are analyzed to assess the extent to which they facilitate allocation of co-ownership shares. The main purpose is to clarify the legal provisions and methodologies related to the determination of co-ownership shares in national condominium systems and bring new insights to countries, which are trying to revise their national provisions for fairer implementations.@en

This paper presents an information system artifact for the fiscal aspect of land administration, a valuation information model for the specification of inventories or databases used in valuation for recurrently levied immovable property taxes. The information model is designed as an extension module of ISO 19152:2012 Land Administration Domain Model (LADM), which is an international standard for land administration. LADM Valuation Information Model is supposed to facilitate all stages of immovable property valuation, namely the identification of properties, assessment of properties through single or mass appraisal procedures, generation and representation of sales statistics, and dealing with appeals. Therefore, it enables the recording of data concerning the parties that are involved in valuation practices, property objects that are subject of valuation, their characteristics and other datasets used for and produced within single and mass appraisal procedures. Moreover, it enables development of valuation maps, and property price records needed to assess changes in property values, as addressed by the New Urban Agenda which is as an extension of 2030 Agenda for Sustainable Development for urban areas (cf. Clause 104). The ultimate purpose of this research is to provide governments with a common basis for the development of local or national databases, enable integration of valuation databases with cadastral databases, and guide the private sector in the development of information technology products.@en

The geometric, legal, physical, economic, and environmental characteristics of property units are utilized in valuation activities. Property valuation registries and databases are supposed to record these characteristics in relation to property units that are subject to immovable property valuation. Moreover, the links between valuation registries and the other land administration registries such as cadastre, land registry, building and dwelling should be specified. Apart from procedural valuation standards, there is no internationally accepted data standard that defines the links and semantics of property valuation databases. The ISO 19152:2012 Land Administration Domain Model (LADM), as an international land administration standard focuses on legal requirements, but considers out of scope specifications of external information systems including valuation and taxation databases. A recently started joint activity under International Federation of Surveyors (FIG) Commission 9 (Valuation and the Management of Real Estate) and FIG Commission 7 (Cadastre and Land Management) has developed an information model for the specification of valuation information maintained by public authorities especially for property taxation. This paper investigates the use of INTERLIS tools for the technical implementation of the Valuation Information Model, which has been developed as a valuation extension of ISO 19152:2012 Land Administration Domain Model (LADM). INTERLIS is a Swiss standard that enables modelling and integration of geographic data sets. It provides a conceptual schema language that can be used to specify a data model in a neutral system environment, similarly, class diagrams of the Unified Modeling Language (UML). It is compatible with international standards like UML, XML and GML. INTERLIS also provide some tools for the implementation of conceptual models into technical models. The core LADM, a number of the ISO191xx base models and some LADM country profiles were already expressed in INTERLIS standard. This paper presents definition of classes, code lists and constraints of the LADM Valuation Information Model and its Turkish Country Profile in INTERLIS. It also discusses possible advantageous of INTERLIS tools (UML editor, compiler, checker, validator and loader) such as system neutral data exchange format, compatibility with relevant international standards, reusable and extensible conceptual schema language, and automatic translation from the conceptual model to physical model.@en

The challenge to develop interactive information services for new domains is supported by Knowledge Organization Systems and Services (KOS), which model the underlying semantic structure of a domain through classification systems, thesauri, gazetteers, or ontologies. The ISO 19152:2012 Land Administration Domain Model (LADM) is an international standard regarding the management of information about ownership, value and use of land. The current version of LADM addresses legal and administrative aspects; the standard revision starts in 2017, according to ISO’s periodic maintenance procedure. A group of researchers have initiated the development of a valuation component of LADM in terms of a draft extension module. It concerns the fiscal parties involved in the valuation practices and fiscal real property units that are the objects of valuation (see Çağdaş et al., 2016). The present paper aims at supporting this initiative by providing a domain vocabulary and thesaurus. The presented Valuation Thesaurus is developed according to the ANSI/NISO Z.39.19-2005 ‘Guidelines for the Construction, Format, and Management of Monolingual Controlled Vocabularies’ and includes terms derived from international valuation standards, such as European Valuation Standards (TEGoVA, 2012), International Valuation Standard (IVSC, 2013), Standard on Mass Appraisal of Real Property (IAAO, 2013a), Standard on Automated Valuation Models (2003), Standard on Ratio Studies (IAAO, 2013b). It is encoded through the Simple Knowledge Organization Systems (SKOS) specifications developed by World Wide Web Consortium (W3C) for standardized representation of structured vocabularies. The Valuation Thesaurus reveals the core semantic of the immovable property valuation domain, and therefore supports the identification of candidate classes, class attributes and relationships for the further elaboration of the mentioned LADM Valuation Module.@en

Immovable property valuation is performed by public sector actors for several land management activities, such as property taxation, expropriation or compulsory purchase of land, land re-adjustment and land consolidation; and private sector actors perform valuation for purchase, real estate financing, investment analysis, and further property transactions. The valuation process returns estimated value (e.g. market value) of property units based on their legal, physical, geographic, economic, and environmental characteristics, as recorded at public registries or observed on location. The ISO 19152:2012 Land Administration Domain Model (LADM) presents a conceptual schema for the specification of property units and their legal and geometric characteristics recorded at cadaster and land register, and relates these datasets with other property related datasets (e.g., valuation, taxation, land use, land cover) recorded at external databases. A recently initiated collaborative research (see Çağdaş, 2016) aims at developing a data model for one of these external databases, in terms of a Valuation Module for the ISO 19152:2012 LADM which is supposed to define semantics of valuation databases maintained by public authorities especially for immovable property taxation. The present paper presents preliminary results of this initiative, and describes a draft version of the Valuation Module which specifies the input and output data used and produced when single or mass appraisal processes are performed according to published standards and recommendations. It also presents a questionnaire which was prepared to create an inventory of valuation applications all over the world, and will be used as source data for the elaboration of the draft module. The paper also opens a discussion about this initiative, and calls for contributions of other relevant bodies (e.g. FIG, OGC, TEGOVA, IVSC and IAAO) for the further development of the draft Valuation Module.@en