Juristica International

1. Things

Mutual understanding of the law of ‘property’ or ‘things’ in Europe is at present an especially arduous undertaking. The problem starts with just isolating a suitable designation for the reference point for proprietary rights. Whilst it is not possible to develop the thesis here, *1 I would maintain that, as a first rough-and-ready categorisation for the purposes of pan‑European stock-taking appraisal, one should distinguish between ‘objects’, ‘objects of commerce’, and ‘things’. ‘Objects’ encompasses everything apart from ‘persons’ that is susceptible to the application of rules of private law, an ‘object of commerce’ is an ‘object’ that can be the subject matter of a sale or gift, and a ‘thing’ is anything that can be made the reference point for a right that enjoys protection against third parties and is thus ‘absolute’ (in the sense that it is not merely relative). The best approach is to distinguish between real and normative things. Real things exist independently of law; have an intrinsically formed and demarcated corpus; and, in consequence of this attribute, are capable of forming the subject matter of property rights. Normative things, in contrast, do not subsist as a matter of nature; they owe their existence and their capacity to be the reference point of property rights solely to an exercise of legal imagination—legal norms, in other words. This is the case, for example, not merely with regard to debts and other rights to a performance and for shares in companies and partnerships but also even in relation to parcels of land, or Grundstücke. Grundstücke belong to that set of normative things that in most legal systems are capable both of being owned and of being the subject matter of other property rights; claims and shares, on the other hand, are normative things that are susceptible only to (mere) property rights, not to ownership as such.

2. Terminology

Normative things may be subdivided into things with a physical substratum and purely normative things. Both have hitherto lacked a uniform European terminology. With regard to things in the first group, the word ‘Grundstück’ (literally meaning ‘piece of land’), which is also invoked by Germany’s Bürgerliches Gesetzbuch, or BGB (albeit with a technical signification of its own), seems to all intents and purposes an appropriate label within the domain of German-language legal scholarship. The German language simply lacks a better word. In the end, some word has to be used, and ‘Grundstück’ is at least not a bad choice. Of course, each legal language must find its own expression for the Grundstück concept. That the common law (which is not alone in this) lacks a genuine linguistic equivalent for Grundstück *2 and that even the legal systems that invoke the word as a terminus technicus associate it with variant meanings *3 is simply something that has to be taken on board. For legal scholarship in the English language, no ready candidate presents itself, for terms such as ‘land’ and ‘parcel [or plot] of land’ already carry very different signification. Their inappropriateness emerges all the more clearly as we probe the ramifications of the Grundstück concept. A tentative suggestion—inspired by the official English-language translation of the Swedish Land Code (the Jordabalk, or JB) *4 —might be ‘land unit’. The Estonian language, I am informed, has no difficulty here and can operate with the word ‘maatükk’.

3. Entities of the landscape capable of being the subject matter of property rights

What, in substance, is at issue? The answer is that, in forming Grundstücke (or, more precisely, entities for which we use that nomenclature in the text that follows), legal systems create objects in the landscape that are capable of supporting property rights. A landscape or terrain, although readily perceptible to the senses and hence often (but rashly) labelled ‘corporeal’, is not in itself a thing. Things—that is to say, entities capable of being the reference point of property rights—come into being within a terrain only once it is parcelled out. It is only after subdivision into distinct plots of land in accordance with the rules of law created for that purpose *5 that subsisting or potential *6 entities capable of supporting property rights emerge—namely, Grundstücke.

4. The purpose of forming Grundstücke

To understand what Grundstücke are, one must first address the preliminary question of why one actually needs the legal concept of Grundstücke. The answer varies from one field of law to another. There are large areas of law that require the notion of ‘movables’, but not that of Grundstücke, in order to reach their goals; as a rule, criminal law belongs to that category. *7 Conversely, even though they are all concerned with Grundstücke, property law, on the one hand, and, for example, tax law, land‑surveying law, planning law, and construction law on the other, need not read the concept in the same way and indeed do not do so. *8 Not even the law of obligations and the law of property necessarily operate at all times to the same end with the notion of Grundstücke; therefore, they also endow it with distinctly different content. *9 It follows that one has to confine oneself to a property-law notion of Grundstücke and, as a first step, settle for the proposition that the formation of Grundstücke serves the purpose of setting up property rights for the usable parts of the planet. Without Grundstücke, that would be impossible: without them, there would be no entity susceptible to control; no‑one would know which part of Earth is the subject matter of the relevant property right.

5. Products of imagination

Grundstücke for the purposes of property law are, accordingly, things in which, as in the landscape from which they are cut out in normative excision, a physical substratum inheres. The so-called law of immovables refers to this at numerous points. Indeed, a not inconsiderable number of the property rights that may be acquired in accordance with its rules would otherwise be quite inconceivable: rights of occupation and rights of way, to name but two, are cases in point. That does not mean, however, that Grundstücke owe their character as things to the materiality of the soil that forms part of them. The opposite is the case. Properly analysed, their element of earthy foundation does not even confer on them the quality of corporeality. Of course, one can stand in a field and get one’s shoes dirty; in this sense, one may say there is a ‘corporeal’ thing when referring to the field. That, however, is not the sense of ‘corporeality’ that is determinative for the purposes of property law. The paramount task for this ‘law of things’ lies, rather, in constructing an ‘entity’ in the first place—that is, in constituting as a normative matter a spatial unit capable of supporting property rights. *10 Real things derive from their corporeality a demarcation to other things; this determines their capacity to be the subject matter of property rights. The position is different for Grundstücke. They must firstly be fashioned by the legal system into a thing (into a corpus), and, moreover, this must be done from all sides—i.e., in the airspace, in the earth, and in the surface area. Their characteristics determined by the physics of nature are (as such) actually an obstacle to the quality of being a thing. This issue can be overcome only by the legal system. Consequently, Grundstücke owe their existence and their capacity to be the subject matter of property rights entirely to property law. Grundstücke are admittedly things with a physical substratum, but they are nonetheless normative things. They resemble the geometric figures that would arise if, by means of a computer program, three-dimensional gridlines were superimposed on the farthest-flung part of the earth. In the end, Grundstücke in the sense applied in property law are products of imagination. Grundstücke do not exist as a product of nature—that is to say, they are not separated from one another by corporeality. Their individualisation is a consequence of legal intervention. One could say that Grundstücke are needed everywhere, yet they are required only where people monopolise not merely the use of goods and rights but also the use of their living space on Earth by means of property law. Societies of hunter‑gatherers do not have a concept of Grundstücke; planned economies need them only to a limited extent *11 ; and for the use or exploitation of the oceans and sea beds, the notion of constructing Grundstücke is unworkable in its very approach. That is because the formation of Grundstücke for the law of property serves the purpose of monopolising resources in the hands of private individuals or corporations. Such monopolisation is ruled out in those regions that belong, or should belong, to everyone.

Because Grundstücke are legal constructs, they can only be partitioned *12 and merged in accordance with legal rules. The partitioning of Grundstücke is an everyday occurrence; merger, in contrast, is not. Nevertheless, it remains correct that the number and size of Grundstücke may be increased and decreased. What cannot be increased is only the land itself that a Grundstück normatively requires for its formation. That makes interests in land a particularly coveted asset. That asset’s monopolisation necessitates stable relations, and stable relations demand a large measure of legal certainty. Where something is very much coveted, moreover, it is unsurprising to find from a comparative-law perspective a variation in the breadth of normative regulation which is often quite appreciable. The law on the formation of Grundstücke and the law on the use of Grundstücke confirm this. The law on the formation of Grundstücke is concerned with striking the difficult balance between party autonomy, with aspirations for polymorphism in legal transactions, and the imperative of protecting third parties against excessive complexity; the focus in the law on the use of Grundstücke is on ordering optimally tiered entitlements in relation to land among as many individuals and legal persons governed by private law as possible.

6. Corporeality, space, and normativity

6.1. A fixed connection with the land

It is repeatedly asserted in discussion of Grundstücke that they are made up of areas, ‘portions of the surface of the earth’. This is correct in so far as an object of commerce can be characterised as a Grundstück only if it is firmly connected to the ground, the fonds de terre (French civil code, Article 518). *13 It is incorrect, however, to regard a mere area of the ground as a Grundstück: nobody can step into a two-dimensional area, grow crops on it, or build on it; in terms of property law, one cannot do even the slightest thing with it.

Although its physical substratum—the ground—is, accordingly, insufficient in itself to form a Grundstück, it remains necessary as a requirement in the construction of Grundstücke. Without a fixed connection with the land, no object becomes a Grundstück capable of supporting property rights. The airspace above a house is not a fit object for separate ownership, even if (in cities) money is expended in vast amounts for permission to use it via encroachment with an overhanging high-rise building and the transactions may be labelled a ‘sale’. *14 The converse position, which Section 3(e) of the Irish Land and Conveyancing Law Reform Act 2009 assumes with the proposition that different layers of air above a building may have different owners, *15 does not convince me. A layer of air remains just a layer of air, though encapsulated in measurements of length, breadth, and height; it still does not form a corpus. The open volume for playgrounds and car parks under a modern stilt or pillar construction forms part of the co-ownership of all the flat-owners in the same manner as a dependent part of the Grundstück. For it to become a Grundstück in its own right and thus an independent thing, the open space would have to be enclosed. Equally, someone who has established a dwelling on a houseboat *16 or the top deck of a double-decker bus cannot claim to have a Grundstück of their own. Neither boat nor bus has a fixed connection with the water over which the boat floats or the ground on which the bus stands. *17

6.2. Space

A Grundstück captures a space. *18 That space arises from the notional demarcation from other spaces. Property law, as a notional starting point, draws its horizontal boundaries (offset vertically upward and downward) in parallel to the boundary lines that are projected by survey in two dimensions on the earth’s surface. The latter often occurs by resort to a cadastre (if there is one)—i.e., an official description of the parcels of land. The vertical lines run upward and downward perpendicularly to the boundaries that delimit the land as a horizontal plane. Both lines—the horizontal and the vertical—serve to demarcate and define the Grundstücke—both in relation to other Grundstücke and as against spaces devoid of Grundstücke. Everything that the contours of the space delineate (not, we note, everything that is to be found within that space) is the Grundstück.

The image of the Grundstück as a cube (which would arise from a square ground plot) is, however, an illustrative simplification. That does not have anything to do with the curvature of the earth, which for the purposes of property law for the most part can in any case be disregarded, and nor has it anything to do with the fact that the formation of Grundstücke is not dependent on adherence to particular geometric figures; even in the two dimensions of the surface, Grundstücke need not possess straight boundary lines. Rather, the aspect of the distance of the upper and lower horizontal lines from the contours of the (notional) ground area is what cannot be expressed meaningfully for property-law purposes in numerical measurements. Grundstücke do not end anywhere within (for example) 200 metres above and 30 metres below the surface of the earth. *19 Such a rule would not make sense for property law, because it would be too inflexible. The monopolisation of powers over an individual’s living space must be shaped effectively, of course, so that investment in Grundstücke is worthwhile, but it must not exceed the degree of exclusive control that is tolerable for the commonwealth. That forces each legal system to make difficult evaluations of competing interests. Quite how far the subject matter of an immovable property right should extend vertically can be determined (in contrast to the horizontal limitation) only in consideration of the nature of the ground, the permitted modes of use, the location, and the interest of the community in also using the relevant space. In consequence, Grundstücke ‘taper off’ in height and depth. They may vary in their height and depth for different purposes and in a manner depending on their location and features. *20

6.3. Subject matter and right

This peculiarity of Grundstücke is put into words more easily and handled more practically if it is visualised not from the standpoint of the subject matter itself but from the perspective of the particular rights in Grundstücke that are allowed. Seen in that manner, the model works without exception. European legal systems continually change perspective so far as provisions determining Grundstücke are concerned. They substitute for the description of the subject matter Grundstück a restriction of the content of the property right permitted to subsist in respect of it. As a frame of reference they, for the most part, define the most extensive property right in a Grundstück—on the continent, civilian ownership. In doing so, they implicitly also give an affirmative answer to the question of whether the same concept of Grundstück is really fitting for all property rights; the efficacy of the so-called limited property rights too is specified according to its content and not according to the volume of the thing to which it refers. A mortgage has the same Grundstück for its subject matter as ownership or another property right does. *21 Were the law to proceed otherwise and assign each property right and its specific configuration by the parties to its own Grundstück, the legal position would become dramatically complicated. Admittedly, possession assumes a special role. If to some extent the law on possession recognises possession of a part, it also recognises subject matter distinct from that over which ownership and other ‘genuine’ property rights subsist; consequently, acquisitive prescription of parts of another’s Grundstück is made possible. *22 However, this merely confirms that everywhere possession oscillates between being a state of affairs and being a right. Since in England it is not Grundstücke that are registered but estates, some questions are posed there rather differently. Some property rights, such as rights of way and hunting rights, define their spatial reference points themselves, so to speak. Their outer boundaries are determined by the same rules that fix the outer boundaries of an estate. In other words, they are not tied to one or more Grundstücke; instead, they constitute independent units themselves.

The change in descriptive level from entity to ownership thereof is, admittedly, merely a dictate of practicability, but in theory it is not dishonest just because the existence of a thing is inseparably bound up with its capacity to be or become the subject matter of a property right; the notion of a thing is co-determined by the content of the property right. Hence, one may say that a Grundstück ends where the owner’s entitlement to use ends—and that is the point from which the owner has no mere interest in user that is worthy of protection.

Because Grundstücke are conceived of as (normatively) demarcated spaces, minerals and other resources in the soil do not themselves constitute Grundstücke—even when, as seams of coal are, they are visibly set apart from other layers of earth. At best, they are immovables.

6.4. The formation of Grundstücke above and below the ground surface

Linguistically, the German word ‘Grundstück’ denotes ein Stück des Grundes—literally, ‘a piece of ground’. A Grundstück is, accordingly, in the literal sense a surface, whereas a Grundstück in the legal sense is a space. To regard a Grundstück for the purposes of property law as a ‘piece of ground’ is to nurture a false conception of the ‘corporeality’ of Grundstücke. That point, together with the fact that nowhere today must ‘ground’ and ‘building’ necessarily be united in the same hands, makes it possible for space above and below the surface of the earth also to be regarded as Grundstücke for the purposes of property law, if the latter ascribes to them an independent capacity to be the subject matter of property rights. What is indispensable is merely the proposition that things designated as Grundstück must be firmly connected to the surface of the ground. All other aspects, in contrast, are merely a question of the effectiveness of juridical concepts. A spatial understanding of the concept of Grundstück, applied consistently, could appreciably lighten the load in the conceptual toolbox of property law.

Since all legal systems of Europe migrated (once more) towards the idea that at least certain parts of buildings—sometimes even entire buildings and other edifices constructed by humans—are to be regarded as distinct entities in property law, they have in essence effected a separate formation of Grundstücke in the space lying above and below the surface of the ground. In this manner, flats and other artificial spaces have normatively been rendered independent things. An obvious step is to regard them as Grundstücke on the basis that, in accordance with the provisions of the relevant legislation (e.g., on opening of a separate land registry file), they are separated from the other flats in the same building. The same applies to whole houses, individual storeys, cellars, and even naturally occurring subterranean spaces. Wherever ownership of Grundstücke is divisible horizontally as well as vertically, one must also tackle the question of which entities arise on account of the horizontal division. In terms of property law, they can only be Grundstücke in their own right.

6.5. Formation of Grundstücke by partition of land

A Grundstück has to be individualised if it is to be able to discharge its function as a thing. The individualisation is effected by partition of the land in accordance with the rules of the law. In ally systems, those rules invoke the geometric figure of the two‑dimensional area. Information about its size in square metres is not in itself sufficient to identify that area. *23 What is needed instead is its contours and its fixation by points of reference *24 ; the fewer the demands a legal system makes regarding the form of a Grundstück and the more irregular its contours may be, the more such points of reference are needed. The area projected onto the planet by the contours and points of reference remains for its part a merely notional construct. That is hardly reflected in everyday speech, of course: in rural settings, people often speak of their ‘area’ when they mean their Grundstück(e). In that case, spatial connotations reverberate in the word ‘area’. It also enjoys an echo in the law, because if one knows the contours and the position of a Grundstück, one can set about defining the space that said Grundstück fills. The circumstances in which Grundstücke arise in Europe do not appear to have been grasped in all their details; it remains a task of comparative legal historical research to shed light on the subject. *25 Two basic models come into question. It is conceivable that at the start there was an occupation of parcels of land by earlier inhabitants and immigrants—made manifest to all and sundry by some means or other and, at any rate, accepted later by the legal system. However, it seems more realistic to suppose that at the beginning of the aeon that has moulded our present-day law, land was allocated to its users under a hierarchical feudal system of grants with the nature of a franchise: a legal transaction as a matter of form but an act of sovereignty as a matter of substance. In England, the consequences of this model are still palpable to this day. *26 In the allocation of landed estates for the grantee’s own use, the first step was completed towards the formation of Grundstücke. The smaller the sub-units became, the more precisely the course of the border had to be marked out. A Grundstück was identified in that allocated parcel of land as soon as the legal system furnished the private rights referable to it with erga omnes effects and permitted their transfer. Formation of Grundstücke and recognition of ownership of land went hand in hand: in allowing ownership of land, one created Grundstücke; in creating Grundstücke, one made ownership of land possible. In contrast, the formation of Grundstücke and the substance of ownership are not interwoven: the emergence of Grundstücke does not presuppose a notion of ownership that has a civilian character—that is, a concept in which the right of ownership is perpetual and indivisible. There is nothing in the internal logic of property law that compels one to deploy an identical right of ownership across all types of things; it is only necessary that each of those rights of ownership specify the subject matter of the right.

6.6. Changes in the Grundstück’s make-up

Save for special restrictions on dealings, the formation of a Grundstück is bound up with the possibility of transfer and acquisition of ownership of it. Grundstücke are not, however, entities that are fixed for all eternity. Their aggregate number can be increased by partition and sometimes may even be reduced by merger. With Grundstücke, such processes are, of course, clearly more complicated than with real things. To achieve the same effect with real things, one need only break them up, take them apart, or assemble them in such a way that a new commodity comes into being. In each case, a merely physical occurrence suffices to bring about a new object capable of being owned. Grundstücke, in contrast, are normative things, and, therefore, their partition and merger too are normative processes. The mere planting of a hedge, digging of a ditch, or building of a wall do not make two Grundstücke out of one; nor does the removal of the hedge or wall or the filling in of the ditch make one Grundstück out of two—not even when they have the same owner. *27

The merger of Grundstücke is a comparatively rare occurrence. Typically, the underlying reason lies outside property law and also, accordingly, the mechanisms are often just as extraneous. The most frequently cited example is the merger of Grundstücke in the course of intervention by public authorities acting under statutory powers so as to effect a consolidation or re-parcelling of land. A more difficult question to answer is whether Grundstücke can also be merged through the exercise of a right of ownership subsisting in relation to them. That is because a ‘merger’ of Grundstücke effected at the initiative of their owners is unproblematic from a property-law point of view only if it is related to two hitherto completely unencumbered Grundstücke—in which case, from the isolated standpoint of the right of ownership, the merger is also meaningless. It is undertaken merely to simplify what has become a complicated set of entries in the land register or in order to satisfy the demands of planning law, which requires a specified minimum area of ground for the construction of a building. One may maintain, therefore, that the consolidation of two Grundstücke is always a process that is prompted by ‘externalities’; it always follows the internal logic of re-parcelling of land and never the logic of property law. Such a process can certainly cause appreciable difficulties for property law if, for the purposes of obtaining planning permission, Grundstücke have to be consolidated that are already burdened with rights of third parties. If a union of two Grundstücke is not precluded precisely because of that complication or at least made dependent on the agreement of the creditors about the priority of their rights in respect of the new Grundstück that is to emerge, *28 the law must itself decide what is to happen with the encumbrances burdening the original Grundstücke.

It is comparatively easy to interpret the partition of Grundstücke coherently in property-law terms. A partition of Grundstücke—if it is not the consequence of action by a public authority under public law (such as a compulsory acquisition)—results either from the fulfilment of a requirement in a norm of property law that provides for the acquisition by operation of law of parts of a Grundstück or from an exercise of the right of ownership of the Grundstück being partitioned that is dependent on the participation of others. The law on acquiring ownership by operation of law has the effect of creating new Grundstücke primarily by virtue of its rules on prescription. Moreover, many legal systems count their law on good-faith acquisition as within this domain. In some places at any rate, on the assumption that there is an appropriate system of land registration in place, those land-registration rules may also effect the creation of new Grundstücke. *29 Under German law, for example, public faith in the land register (see §892 of the German BGB) is related to not merely the property rights it records but also even the very existence of the Grundstück that is registered. *30

Continuity of pre-existing encumbrances poses a far less acute problem in relation to partition, as opposed to merger, of Grundstücke. That is because the universal principle is for encumbrances of the original Grundstück to continue in relation to the newly constituted Grundstück(e).

7. The formation of Grundstücke and the character of the ground

The character of the surface of the earth that belongs to the Grundstück is, as a rule, irrelevant for the actual formation of the Grundstück. The subject matter may be either an urban space or a rural one; equally a Grundstück can consist of a building plot, arable land, meadowland, woodland, or waste land, and it may lie in the hills or on the plains. The surface of the ground is inconsistent with the capacity of its parts to be the subject matter of property rights only if the physical character is such as to cause the legislator to reserve land of the relevant type for state ownership or in some other way render it extra commercium. Statutory provisions that prohibit the partition of agricultural or forestry land into units below a set minimum size ultimately have the same effect. That is because such rules boil down to the rule that agricultural land and forestry land must be of at least the given minimum size if they are to qualify as the subject matter of property rights. In all other cases, however, the classification of Grundstücke according to the character of the surface of the ground is material only with respect to the type of property rights possible for use of that land. *31 Where, additionally, special modes of acquisition fall to be considered, that is typically not a matter of property law but rather of public-law requirements to obtain consent. A more precise analysis is called for only for those spaces whose visible surface is partly or completely filled with water. In those cases, a distinction has to be drawn along several lines—in particular, according to whether the water is flowing or static and, furthermore (in either case), whether the water falls under a regime of public law or of private law. However, consideration of that aspect of matters cannot be developed further within the confines of this contribution.

8. Grundstücke, not immovables

There remains the question of the relationship between ‘Grundstücke’ and ‘immovables’ (‘immovable things’). Of course, one might take the view that all is entirely the same whichever word one uses to denote the parts of the planet Earth that are capable of being the subject matter of property rights—be they Grundstücke; immovables (or immovable things); or, to borrow from the title of Alfred Ross’s immortal article on legal realism, simply ‘tû‑tû’. *32 A fair number of jurists thus regard ‘Grundstücke’ (or, more precisely, the relevant national language’s word for a parcel of land) and ‘immovable’ to be one and the same. *33 That is true even for many in Germany, where the BGB takes pains to avoid the notion of an ‘immovable thing’ and refers only to ‘Grundstücke’. In recognising ‘movable things’, the BGB also implies its counterpart—the ‘immovable thing’—even though it uses the term ‘Grundstücke’. *34 While that might be so, it does not resolve our difficulty. That difficulty, moreover, is not a mere consequence of the fact that other legal systems regard the fonds de terre, tierras, or whatever they may be called as only a subset of immovables (such that every plot of ground is an immovable but not every immovable is ground) while the common law manages to avoid both concepts and makes do with ‘land’. In their essence, they all display the same weakness. They classify entities according to a criterion that is of relevance to property in, at best, secondary contexts; in other words, they tackle the secondary question before the main one. The first question, which alone is the focus of this contribution, is this: what exactly is the specific subject matter of an exclusive right of use of the ground? That question is not answered by the term ‘land’ or ‘immovable’ (referring to immeuble or unbewegliche Sache); someone who actually equates immovables and Grundstücke merely swaps words without advancing the substance of the matter one jot. This is because one might perhaps say that the surface of the ground, a house, a body of water, a farm animal *35 , or a right over another’s Grundstück is ‘land’ or an ‘immovable’ but not that they are Grundstücke in the sense that, in our view, matters.

The notion of an immovable thus extends appreciably further than does the notion of a Grundstück. There is an almost endless number of objects that, though not Grundstücke, are classified by national legal systems as immovables. *36 In using the term ‘unbewegliche Sache’, ‘immeuble’, or ‘land’, the relevant national terminology does not encapsulate the proposition that these items are the potential subject matter of property rights effective against third parties. Astonishingly, there does not appear to have been a word created, to this day, for that attribute that is cut out for Europe. We believe that ‘Grundstück’ can fill that gap, as it conceptually grasps the object individualised by the legal systems in respect of which a person asserts a right when he claims to be the land-owner. ‘Immovables’ (‘immovable things’) is a general category no different from categories such as ‘generic goods’, ‘fungibles’, and ‘consumable goods’. A legal system or a juridical dogmatic framework deploys them for purposes different from those for which we propose using the term ‘Grundstück’. The notion of immovables as currently embodied in most of the legal systems that invoke it is concerned with certain issues consequent from the formation of Grundstücke, such as the modes of acquisition and the transfer of rights that must be registered, or with articulating the proposition that a person who has a right of use of another’s Grundstück or a power of sale over it may also have resort to possessions of the debtor that serve husbandry of the land. Naturally, such rules have to be developed separately, not merely as between distinct types of property rights and, in a European context, moreover, from one legal system to another. *37 Furthermore, there may be a need to distinguish not between movables and immovables but, rather, between registered things and things not required to be registered (as Article 3:10 of the Dutch Bugerlijk Wetboek does). More important, however, is that such rules always presuppose another—namely, that the relevant legal system permits and facilitates the excision of entities from the land that are capable of forming the subject matter of property rights. The ‘movable’/‘immovable’ dichotomy therefore fails to hit the essential target. *38 A ‘movable’ is capable of being owned not because the object is movable (running water and dockside rail-mounted gantry cranes *39 are movable) but, rather, because it is spatially separated from other objects and, therefore, as a real thing, capable of being exclusively assigned to a party. An ‘immovable’, in contrast, is not by nature a thing; it only becomes a thing when it assumes the form of a Grundstück. Categorising things as ‘movables’ rests on a fuzzy concept, though, for the most part, the repercussions are not especially disruptive. If, however, one contrasts ‘movables’ against ‘immovables’ and moulds the latter into its own legal category, the fuzziness snowballs into a serious conceptual problem.