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Managing Legal and Physical Complexities of Urban Environments
1.1 Land Administration Systems and Urban Complexity
Land administration systems provide an overarching framework to design and implement effective policies and strategies associated with the planning and development of land in line with the goals of sustainable development (Williamson et al. 2010). These systems adopt an organized approach to addressing issues associated with land and property assets by considering social justice, economic prosperity, and environmental sustainability. Land administration systems are critically important for developing a national infrastructure for any country around the world. The four underpinning functions of a modern land administration system are:
- Land tenure: This refers to procedures defining and securing legal rights and boundaries associated with land and properties.
- Land value: This function specifies the assessment processes for taxation and valuation of land and properties.
- Land use: This refers to the procedures controlling the usage of land in line with planning policies and regulations developed at national, state, and local levels.
- Land development: This includes the processes for designing, planning, and building new physical structures.
In a modern society, land is a broad concept comprising the land itself, physical objects and cognitive spaces within underground and aboveground areas, physiographical features (such as waterbodies and geological substratum), and airspaces. This signifies the fact that modern land administration systems should develop and implement effective solutions for spatial management and subdivision of an entire jurisdiction in three dimensions. Three-dimensional (3D) spatial extents of rights, restrictions, and responsibilities (RRR) associated with land are currently recorded and stored using cadastral maps and subdivision plans. As outlined by the International Land Administration Domain Model (LADM) standard, āa right may provide a formal or informal entitlement to own or do something, a restriction is a formal or informal obligation to refrain from doing something, and a responsibility is a formal or informal obligation to do something.ā
Throughout the last few decades, rapid urbanization and population growth have meant an unprecedented pressure on the development and use of land in cities around the world. Due to the limited areas of land in urban environments, there has been a prolific growth of built assets within these environments in the vertical dimension. Examples of these assets are multi-story, high-density, and multi-functional building developments, shopping centers, passageways above and below streets, gas and water pipelines, electricity and communication cables, underground carparks, and tunnels.
We are entering an era where more people will be living or working in multi-owned urban developments. Owners of apartments are liable to contribute to the maintenance of the apartments and common areas. Buyers or renters are given documents about what they buy or rent, or the opportunity to obtain them. This indicates that multi-story properties in urban areas are not only becoming a significant component of the land market and economy in many nations, but also generating a rising tide of social, economic, and environmental issues impeding the move towards sustainable development.
Urban land administration mainly refers to processes associated with managing legal ownership of properties in multi-story developments which are the most prominent components of an urban built environment. These developments typically comprise a wide range of RRR spaces associated with privately, commonly, and publicly owned properties. For instance, a private property can be considered as an apartment unit and its carpark, while a common property can include various common areas spanning throughout the building (e.g. corridors, lobbies, elevators, and gym).
The requirements for recording RRR information in each jurisdiction depend on the guidelines and procedures developed specifically for that jurisdiction. Therefore, each jurisdiction adopts its own unique approach for implementing land administration systems in urban areas. However, urban land administrations practices among all jurisdictions commonly rely on 2D-based methods of partitioning the spatial extent of RRR spaces within multi-owned developments.
1.2 Legal Partitioning of Multi-Story Buildings: 2D-Based Approaches
Building subdivision practices currently use 2D analogue or digital plans for delineating the legal limits of properties in multi-story buildings. These plans typically include multiple pages, each of which provides a projection of 3D ownership spaces from a specific viewpoint. These projections typically include both vertical and horizontal representations of 3D ownership spaces (see Figure 1.1). As indicated in Figure 1.2, in some cases, a volumetric representation of an ownership space from an isometric viewpoint is delineated in these 2D plans (such as in Queensland, Australia).
FIGURE 1.1
An example of floorplan and cross-section views of ownership spaces. (From Victoria State Government 2019.)
FIGURE 1.2
An example of volumetric representation of ownership space on a 2D plan. (From Land Title Act 1994.)
2D-based representation methods are quite efficient in multi-story buildings with simple structural forms. However, the efficiency of 2D plans is questionable in buildings with higher levels of spatial and functional complexities. Spatial complexity refers to architectural and structural elements defining the internal and external shape of a building in its various parts. Functional complexity indicates the usage and access of building facilities differentiated among various groups of a buildingās inhabitants. For example, a multi-purpose building could have various access requirements to support retail, commercial, and residential functions. Therefore, there are a number of communication challenges in delineating legal boundaries of properties when 2D-based methods of legal partitioning are used in complex buildings. These challenges include:
- Difficulties in integrated representation of boundaries of ownership spaces with irregular forms: The complex reality of ownership spaces with interweaving and irregular shapes may not be successfully recorded and managed via 2D paper-based drawings, or even 2D digital plans, and this forms the first technical challenge associated with delineating boundaries (see Figure 1.3).
- Use of numerous 2D floorplans and cross-section diagrams to fully represent all ownership spaces in high-rise buildings: A large number of 2D diagrams results in difficulties finding the right floorplan and cross-section diagrams that, when viewed together, represents the horizontal and vertical boundaries for a specific private ownership space (Jazayeri, Rajabifard and Kalantari 2014). Consequently, interpretation of ownership boundaries for each apartment unit in high-rise developments is a time-consuming task. Additionally, although 2D subdivision plans can be functional to some extent, this 2D-based method of representation may be computationally extensive, as multiple pages of 2D diagrams are used to describe RRR information associated with superimposed properties in high-rise buildings. As an example, over 50 pages of 2D plan drawings are required to effectively present the overall parcel, as well as individual property boundaries, for a 40-story apartment building in the City of Melbourne (see Figure 1.4).
- Problems in accurate understanding of textual information: 2D subdivision plans usually include textual notations (see Figure 1.5) which are difficult for nonspecialized owners, who have limited background in understanding subdivision plans, to read and interpret accurately (Shojaei et al. 2014). This textual information typically includes notation regarding spatial location of legal boundaries in reference to the physical structure. Moreover, it can also provide information on what parts of the building belong to the communal area. Accurate understanding of these textual descriptions could be problematic for non-technical people.
- Representation of 3D RRR spaces spanning several stories of a building: While multiple 2D plans can illustrate ownership boundaries for properties restricted to one level, implementing these plans to communicate the ownership boundaries of properties encompassing parts of several levels is a very challenging task. Many multi-story buildings include commonly owned and managed properties (e.g. corridors, stairwells, gyms, etc.). These common property areas typically pass through several building levels and it is a very challenging task to map the boundaries of these areas into 2D floorplans and cross-section diagrams. This challenge is more extensive in comparison with the aforementioned challenges. In Figure 1.6, a common property area, illustrating corridors, stairs, and lobbies, of a multi-story building is shown in red to provide an example of this challenge.
- Ambiguities in interpretation of legal boundaries defined by building elements: Understanding of some legal boundaries, which are defined by referencing building elements, could be problematic for inexpert stakeholders. For example, in Victoria, Australia, legal boundaries inside buildings are mainly defined by using one of three spatial relationships with its corresponding building element: the boundary touches either the interior or exterior face of the building element, or it corresponds with the (virtual) median line of the building element (Libbis 2015). The referenced building elements typically include walls, windows, ceilings, slabs, and doors. These legal boundaries are often denoted by different types of lines in subdivision plans. As shown in Figure 1.7, some boundaries of LOT 1 are defined by referencing the interior face of the wall, door, and window. These physical structures are not shown in subdivision plans. This abstraction could potentially lead to a misunderstanding of these boundaries by a non-expert user interpreting what the lines mean, and hence he/she could easily misunderstand the location of the boundary and RRR information. For instance, a non-specialist owner of LOT 1 may misinterpret interior boundaries as exterior ones. Therefore, he/she may think that the full ownership and responsibility of building elements is entitled to him/her, which is not correct in this...
