Combining 3D Cadastre and Public Law – An Austrian Perspective

3D cadastres as currently designed aim at providing information on private rights (ownership, easements, etc.). However, from an economic perspective, public-law restrictions are at least equally important because they might restrict different kinds of use on the land. This has a dramatic impact on the value of the land. Since land value is crucial for investors or credit institutes, they are equally interested in public-law restrictions as they are interested in private rights. In addition, the 3D objects defined in a cadastre are typically seen as legally independent of each other. This is not always the case, e.g., each apartment in an apartment building must support the structure (apartments and other structure like the roof) above. This must be taken into consideration when defining separate 3D objects. The use of a public-law restriction would provide a simple solution to this. Other regulations may have more unpleasant effects. Asking adjacent land owners to provide land for public services is a standard method in spatial planning. The extent is determined by the planned structure and may be limited by legal rules. The same would be true for 3D structures because spatial planning usually does not only deal with 2D arrangements but also with height information. It is an unfortunate situation, for example, if a small building with only a ground floor is created in an area intended (and suitable) for skyscrapers. However, compulsory purchase could have unwanted effects in 3D systems and finally leads to the question of value: What is the value of a volume floating freely in space

Visibility Analysis in a 3D Cadastre

The implementation of a 3D cadastre is work-intensive and expensive and legitimation of such expenses is necessary. A legitimate path of argumentation is that 2D systems fail to communicate complex legal situations correctly. Also, additional arguments can help to strengthen the position of 3D cadastres and provide support from other professions and social groups. The paper is based on a newly developed model for 3D visibility. We discuss the model and how it can be used for two different application areas. The first is the assessment of property value, where the visibility or invisibility of specific objects can have a big impact. The other example is spatial planning. Spatial planning shall guarantee that cities are working economically and socially, that space is not wasted, and that the planned environment meets cognitive requirements. For example, evidences in spatial cognition show that visibility of landmarks is an important topic for tourism and navigation and should thus be addressed

Height Systems for 3D Cadastres

3D systems are built assuming the existence of suitable height reference systems. However, the earth is neither homogeneous nor flat, the plumb lines are curved and not parallel and the definition of height and the implementation of geodetic height systems is complex. 3D cadastral systems have the same problem. Cadastral systems are designed to persist for centuries. Them the earth itself is changing and this needs to be considered in the system design. The paper starts with a discussion of existing height systems and the determination of height. Afterwards quality requirements for height in a 3D cadastral system are determined using some typical examples. The examples range from a tunnel below the Alps (e.g., the Gotthard base tunnel) to apartments in an apartment building. Deviations must be considered when creating the height system. The paper gives some indication where problems may occur and which pitfalls should be avoided

From Floor Plans to Condominium Rights Through an Augmented Reality Approach

The creation of a 3D cadaster faces a number of different challenges. Two of them are the collection of data on already existing 3D structures and the visualization for non-experts. The paper uses Augmented Reality (AR) technology for the visualization of models created from plans required in Austria to create condominiums. The advantages of such an approach would be: - Since the plans are required for the creation of condominiums, the data already exist and no additional surveying work is necessary. - AR technology might be more intuitive than 3D CAD-systems. Experts in 3D CAD have no problems to work with complex models but the typical person interested in a condominium will have a background in law (e.g., a notary) or economy (e.g., a real estate agent) and people interested in acquiring ownership may have any kind of background. The paper shows how to create a model of condominium from floor plans, import it in the AR environment, and interact with the model. The test setup is described and first results are sketched

Layer approach to ownership in 3D cadastre – a subway case

The paper focuses on approaches to the registration of real property rights in the case of underground or subway tunnels in different EU countries: Austria, Bulgaria, Czech Republic, Croatia, Greece, Poland, Slovenia, and Sweden. The Authors made analysis of the current way of registration of rights to subway tunnels in the chosen countries, including its effectiveness in ensuring appropriate property rights to construct and exploit tunnels. A special attention was given to limitations related to the lack of the possibility to vertically divide the space, i.e. to divide the space into layers, and to refer the ownership right to the layers. Benefits which might be achieved by the introduction of a 3D real property cadastre were pointed out. The analysis of available data concerning the geometry of subway tunnels in particular countries was presented. The authors tried to answer the question whether the accessible data concerning the geometry of subway tunnels allows to generate a 3D geospatial model of a constructed object, and to specify the space which should be determined as a 3D parcel in the 3D real property cadastre, for the purpose of registering property rights for the object (the tunnel)

3D Cadastre in the Case of Engineering Objects, such as Bridges and Road Viaducts

At present, the implementation of cadastral registration of transport investments (such as railway lines on bridges and on viaducts, roads on viaducts, etc.) is performed in the so-called "layer" system. This means that many objects are constructed at different levels (layers) within the space of a given parcel. Several parties may be interested in developing certain fragments of the parcel space; each of them is interested in acquiring rights only to a specified part of the parcel (its specified layer), in which given investment is implemented by that party. The legal conditions binding in many countries do not allow for implementation of such type investments within the space of a someone else's cadastral parcels, based on the ownership right. This is due to the fact, in accordance with the "superficies solo cedit" rule applicable in many EU countries, the ownership right extends above and below the parcel space and cadastral systems do not allow for vertical division of a real property. The conventional 2D cadastre, which does not allow vertical division of the parcel space, forces an investor to buy a whole parcel or to get other rights which allows using a specified space of someone else's parcel, such as easiment rights. Buying of an entire parcel in which space bridges and road viaducts investments will be performed and not being able to divide the land space vertically makes it practically impossible to sell the parcel under a viaduct because following the rule above the viaduct is part of the land parcel. Therefore, the space is not optimally utilised. The easement right has some disadvantages, as it cannot be encumbered with a mortgage; therefore it is not the basis of crediting a given investment. The 3D cadastre allows delineating 3D parcels (from the space of existing 2D parcels) that cover specified fragments of the space and to relate ownership rights to those delineated fragments. Within a 3D cadastre system, such objects can be registered as separate cadastral objects. This allows for the implementation of a line investment in the above-ground space in a flexible way, i.e. it is possible to get financing of an investment based on the mortgage charge of a 3D property and market transactions of the remaining space after delineation of the 3D parcel, covering the bridge or viaduct. This paper focuses on approaches to registration of real property rights in the case of engineering objects, such as bridges and road viaducts, in different EU countries: Austria, Bulgaria, Czech Republic, Croatia, Greece, Poland, Slovenia and Sweden.The authors review the current solutions for the registration of engineering objects in the cadastre, including its effectiveness in ensuring appropriate property rights to construct and exploit such objects, and make a comparison between the countries

3D Real Property Legal Concepts and Cadastre: A Comparative Study of Selected Countries to Propose a Way Forward

The concepts of three-dimensional (3D) real property have been the subject of increased interest in land use management and research since the late ‘90s while literature provides various examples of extensive research towards 3D Cadastres as well as already implementing 3D cadastral systems. However, in most countries the legal aspects of 3D real property and its incorporation into 3D cadastral systems have not been so rigorously examined. This paper compares and discusses 3D property concepts in six selected countries: Austria, Brazil, Croatia, Greece, Poland and Sweden, based on the authors’ national experience. Each of these countries’ legal system is based on different origins of Civil Law, including German, Napoleonic and Scandinavian Civil Law, which can prove useful to research in other Civil Law jurisdictions interested in introducing 3D cadastral systems. Selected countries are on different stages of introducing and implementing a 3D cadastral system; this may contribute to the detection of the main 3D real property concepts that apply as well as deficiencies and malfunctions that prohibit introduction of 3D cadastral systems, highlighting challenges that may have not yet surfaced. This paper aims to present the different legal concepts regarding 3D real property in the examined countries, focusing on the characteristic features of cadastral objects described as 3D within each country’s legal and cadastral framework. The analysis of the case studies revealed that the countries are on different stages of 3D Cadastre implementation, starting from countries with operational 3D cadastral systems, to others where there is yet no interest in introducing a 3D cadastral system. 3D cadastral objects in each country are presented, as well as differences in the regulatory framework regarding definition, description and registration. The paper continues the legal workshop discussions of the 4th International Workshop on 3D Cadastres in Dubai 2014 by analysing the legal concepts of 3D cadastres in the above mentioned countries. The outcome is an overview and discussion of existing concepts of 3D property describing their similarities and differences in use, focusing on the legal framework of 3D cadastres. The article concludes by presenting a possible way forward and identifies what further research is needed which can be used to draft national and international research proposals and form legislative amendments towards introduction of national 3D cadastral systems