OR MORE SUCH BUILDING UNITS

[01] The invention generally concerns a building unit in general and a modular unit construction system comprising one or more such building units.

[02] More specifically, the invention concerns a building unit that comprises a metal frame that is provided with

an upper and a lower frame that are oriented substantially horizontal in the assembled state of the building unit, and

at least 4 load-bearing columns that, in the assembled state of the building unit,

• are substantially vertically oriented, and

• are connected to the upper and lower frame;

wherein the said metal frame is arranged in such a way that it can be disassembled;

and wherein the metal frame is provided with

- a mainly square or rectangular upper frame and lower frame that are oriented substantially horizontal in the assembled state of the building unit, and

- at least 4 load-bearing columns with mainly rectangular or square cross-sections with around enclosed side walls that, in the assembled state of the building unit,

• are substantially vertically oriented;

• are connected releasably to the upper and lower frame; and

• are placed at least at each of the 4 corners of the rectangular or square lower frame and upper frame in such a way that the visible outsides of the said load- bearing columns and the said lower, respectively the upper frame that are adjacent to each other are extending along substantially the same plane or within the space delimited by the visible outsides of the lower, respectively the upper frame.

[03] The invention furthermore more specifically concerns a modular unit construction system that can consist out of one or more of the building units as described above, which can be placed adjacent to one another as well as the one on top of the other. Such a modular unit construction system is particularly suitable as temporary space. More particularly, such a modular unit construction system is suitable as temporary accommodation for trade fairs and other events, temporary office space, temporary catering sector space, temporary school building, temporary childcare facilities, temporary healthcare facilities, temporary changing rooms, and so forth. The building units and this modular unit construction system according to the invention can be used both indoors and outdoors.

[04] At present, similar modular construction systems are already known, comprising a number of building units that can be stacked next and/or or on top of one another.

[05] For instance, in US 2009/0307994, a module for building structures is described. This module comprises a metal "moment" frame, a set of 4 upper corner pieces and a set of two or more composite panels. A metal moment frame is a frame that consists of metal girders and columns that are connected together using a combination of welding and bolts in such a way that the frames can withstand wind loads and earthquakes. The girders and columns of the moment frame as described in US 2009/0307994 are connected together in such a way that they create a top, a bottom and 4 sides.

[06] In EP 2 226 441 , a modular building construction is described that consists out of a number of container-shaped modules or base units that can be placed next to one another or stacked optionally in order to obtain a structure of a specific size and shape. The module as described in this European patent application can be dismantled to give a fixed and undefined frame and various covering elements that can be attached selectively to this frame.

[07] The disadvantage of both the modules as described in US 2009/0307994 and in EP 2 226 441 is that the module has to be transported as a whole to the location where the various modules are assembled into a single unit construction system. The major disadvantage that this generates is that a great deal of space is required during transport of the modules.

[08] There is consequently a need for a building unit and a modular unit construction system that requires less space during transport.

[09] In US 2009/0032530A, such a container is described, which is provided to be disassembled in such a way that it can be folded up into a smaller volume for storage or transport. The container is therewith arranged up of a wall frame comprising an upper, a lower and a surrounding wall and a supporting frame that mounts an upper retaining frame against the upper wall all round, and a lower retaining frame than mounts all-round the lower wall, with the surrounding wall being assembled between the upper and lower retaining walls. Furthermore, the container comprises a joining structure for connecting the upper retention frame to the lower retention frame. This joining structure has a large number of connecting pieces for the purpose that extend between the upper and lower retaining frames, with spaces between these pieces. Each of these connecting pieces comprises an upper connector that has an upper fitting going downwards from the upper retaining frame and a lower connector that has a lower fitting going upwards from the lower retaining frame in such a way that it can be aligned with the upper fitting, and a spindle holder that is assembled in such a way that it is aligned between the upper and lower connectors in such a way that a reinforcement duct is created via the spindle holder between the upper and lower fittings. Furthermore, a large number of reinforcement spindles are places inside the reinforcement ducts that are connected between the upper and lower connectors through the various spindle holders. Each of the reinforcement spindles has an upper part that first in the upper fitting and a lower part that fits \ri the lower fitting respectively, and a middle part that fits in the corresponding spindle holder in such a way that the connecting structures between the upper and lower frame are strengthened in order to provide permanent support for the wall frame.

[10] Such a container has the advantage that the lower frame, the upper frame and the load-bearing columns can be stacked one upon the other for transport. This offers the major advantage of a huge saving in terms of space while transporting the building unit to the place where it is to be assembled. When transport is being handled using a truck with a trailer, various such building units according to the invention can be transported simultaneously on a single trailer.

[11] The disadvantage of a container as described is however that it cannot be assembled and disassembled without mechanical assistance. To fit the spindle holders onto the lower retaining frame, the spindle holders must first be positioned on the lower retaining frame and the whole assembly must then be lifted up to access the horizontal bolt connections in such a way that they can be done up. Moreover, the very difficult accessibility of the horizontal bolt connections means that the container is difficult to disassemble again. To undo the horizontal bolt connections again, the container has to be lifted up mechanically to provide access to the horizontal bolt connections in such a way that they can be undone. [12] A further disadvantage is that protruding parts of the reinforcement spindles that are to be inserted into the corresponding upper and lower fittings have to be very weak because they need to be easily flexible.

[13] Also in DE 9312108, such a versatile container is described, comprising a metal skeleton, more specifically a steel skeleton. The container therewith comprises welded and prefabricated components, such as frame-like basic elements, frame-like roofings and corner elements that are connected together using horizontal bolted connections.

[14] As can be seen on the figures of this German utility model, the corner elements are designed in such a way that the horizontal bolted connection is always accessible. In figure 4b, the horizontal bolted connections are located inside the corner elements and a single side of the corner element is open to allow access to these horizontal bolted connections. In figures 4e and 4d, the horizontal bolted connections are accessible from the outside.

[15] The disadvantage is that it is impossible for these corner elements to have a fully enclosing wall around them. Corner elements such as these are consequently less sturdy.

[16] Moreover, the bolted connections are always visible from one or more sides, which is aesthetically less desirable.

[17] According to a first aspect of the invention, a building unit is provided according to the preamble of the first claim, wherein the said load-bearing columns comprise one or more recesses at each of their ends, and the said lower and upper frames comprise one or more corresponding protrusions, wherein the said protrusions are arranged in such a way that they can be inserted in the respective recesses by means of a loose fit, and wherein the said recesses extend in a substantially horizontal plane in the assembled state of the building unit, and wherein the said load-bearing columns, respectively the said lower and upper frame, at the place where the load-bearing columns are connected to the said lower, respectively the upper frame, at one or more opposing sides that are invisible and are vertically arranged in the assembled state of the building unit comprise one or more openings that in the assembled state of the building unit substantially connect against one another and are arranged in such a way that the said load-bearing columns are releasably connected to the lower frame, respectively the upper frame by means of one or more releasable threaded connections that in the assembled state of the building unit (1) extend through the respective openings, wherein these releasable threaded connections are invisible from the outside of the load-bearing columns and the lower and upper frame.

[18] With a loose fit the joining of two elements of the same nominal dimensions is meant.

[19] The way in which the releasable connections of the load-bearing columns to the lower and upper frame are realised takes care that the assembly and the disassembly of such a building unit can be done very quickly and efficiently. By providing protrusions and corresponding recesses in the load-bearing columns and the lower, respectively the upper frame, that can be brought into each other by means of a loose fit, the load-bearing columns can be positioned immediately at the correct place with respect to the lower and upper frames before they have to be connected together, through which the openings that are arranged in the load-bearing columns and the lower, respectively the upper frame that serve to allow a releasable connection to be arranged between the load-bearing columns and the lower, respectively the upper frame also immediately are being positioned correctly with respect to one another. In this way, the mechanic of the building unit does not always have to check whether the openings in the load-bearing columns are indeed

·.·(, !-. } _{ .> . Allocated in such a way that they are aligned with the openings in the lower, respectively the upper frame. This makes it possible to assemble the building unit according to the invention in a period of one hour. Moreover this type of releasable connection also permits rapid dismounting of the building unit.

[20] In an advantageous embodiment of a building unit according to the invention, the said load-bearing columns are hollow, wherein the said load-bearing columns within this hollow space, at the place where the said opening are located, on each of the sides where the load-bearing columns are connected to the lower, respectively the upper frame, are provided with a reinforcement plate comprising the same number of openings as the ones applied in the load-bearing columns, wherein the said openings in the said reinforcement plates are applied in such a way that these are connected to the openings arranged in ^' the load-bearing columns in the assembled state of the building unit, in order to allow the ^' said releasable threaded connections, that are provided to releasably connect the load-bearing columns with the lower, respectively the upper frame, are applied through the respective openings. [21] This provides more sturdiness to the metal frame and takes care that the building unit does not have any problems with wind loads.

[22] In a preferred embodiment of a building unit according to the invention, one or more of the said load-bearing columns comprise a square recess at each of their ends, and the said lower and upper frame have a cuboid-shaped protrusion that is arranged in such a way that these cuboid-shaped protrusions can be inserted by means of a loose fit in the respective square recesses, wherein the said square recesses extend in a substantially horizontal plane in the assembled state of the building unit.

[23] In a preferred embodiment of a building unit according to the invention, the substantially rectangular or square lower and upper frame comprise an outer frame in which one or more load-bearing girders are arranged.

[24] The said lower and upper frame at the upper side of the outer frame comprises a collar that at least partially extends around the lower, respectively the upper frame, and that the said load-beraing girders and the said collar are arranged in such a way that one or more floor plates within the space delimited by the said collar and supported by the said load-bearing girders can be removably applied.

[25] In order to provide access to the respective releasable threaded connections which are invisible in the assembled state of the building unit, one or more of the said floor plates at each of the places where the said load-bearing columns are releasably connected to the said lower, respectively the upper frame comprises a hatch.

[26] The building unit according to the invention optionally comprises one or more water supply pipes, wherein the outer frame of the lower frame comprises one or more passages and one or more of the said hatches are arranged in such a way that the said water supply pipes can be passed through from outside the metal frame to the inside of the space delimited by the said metal frame.

[27] In a preferred embodiment of a building unit according to the invention, one or more of the said load-bearing columns comprise a drainage pipe for water from precipitation that extends in the lengthwise direction of the respective load-bearing columns throughout these load-bearing columns. [28] The said load-bearing columns that comprise a drainage pipe for water from precipitation preferably comprise a hollow cylindrical protrusion at the end thereof that is provided to be releasably connected with the lower frame, and the said lower frame comprises a corresponding round opening, wherein the said cylindrical protrusion can be inserted into the said round opening by means of a loose fit, and wherein the said round opening extends in a substantially horizontal direction in the assembled state of the building unit.

[29] In an advantageous embodiment of a building unit according to the invention, the upper frame at the upper edge thereof comprises a water-retaining rim that extends around the outer edge of the upper frame and wherein at least one of the floor plates comprises a drainage opening that connect against the said drainage pipe.

[30] This water-retaining rim takes care that the water is drained to the drainpipe via the drain opening.

[31] The upper frame preferably comprises a roofing that is applied in such a way that it extends inside the space delimited within the upper frame.

[32] The roofing therewith is preferably applied on a plate that extends over the space delimited within the upper frame. More preferably, this plate with the roofing is always present within the upper frame. When the building unit according to the invention is used alone, and thus no further building unit is placed upon it, then the upper frame serves as the roof of the building unit and this plate with roofing is the upper plate of the building unit. This roofing takes care that at that moment that no precipitation water can penetrate the building unit. If on the building unit another building unit is placed, then a floor plate is placed as described above on top of this roofing on top of which the next building unit can be placed. The roofing of the lower building unit is then still useful to take care that liquids from the upper building unit cannot penetrate the lower building unit.

[33] In a preferred embodiment of a building unit according to the invention, the lower and/or upper frame comprise one or more lifting elements in order to lift the lower and/or upper frame, the metal frame and the building unit in the assembled state.

[34] In a more preferred embodiment of a building unit according to the invention, the said lifting elements comprise two or more drilled holes that are aσanged in such a way that therein lifting eyes can be applied and that are placed in such a way that the lower and/or upper frame, the metal frame and the building unit in the assembled state can be passed through these passages into the space delimited by the respective outer frame. These lifting eyes preferably are inserted into the said drilled holes using a threaded connection.

[35] More preferably, 4 such drilled holes are applied symmetrically to two opposite sides of the outer frame of the lower frame. An assembled building unit can in this way be hoisted very easily by means of for instance 4 lifting chains that are connected to a central ring and that each are connected to a respective lifting eye.

[36] It should be noted that also other forms of lifting elements can be provided in order to allow the assembled metal frame to be hoisted. For instance, recesses can be provided to allow the forks of a forklift truck to be inserted. This is however aesthetically less pleasing. Another system is described in US 2009/0307994 in which connecting elements are used that are applied to the corners of the upper frame in order to let the assembled metal frame be lifted. This is also aesthetically less attractive because additional top pieces are present on the corners.

[37] In a particular embodiment of a building unit according to the invention, the outer frame of the said lower and/or upper frame comprise one or more passages that are provided in such a way that one or more cables for utilities can be passed through these passages into the space delimited by the respective outer frame.

[38] In another particular embodiment of a building unit according to the invention, the said cables for utilities are passed through the said load-bearing columns in the assembled state of the building unit, wherein in the said load-bearing columns, and in the lower and upper frame, at the place where the said load-bearing columns are releasably connected with the lower, respectively the upper frame, one or more passages are provided for passing the said cables for utilities through.

[39] With utilities, in the light of the invention, electricity, telephone, television, Internet, video and the like are meant. [40] Providing such passages has the advantage that the cables for the utilities are concealed, which has both an aesthetic benefit and the benefit that the cables can then no longer become damaged.

[41] In order to be able to optionally close off one or more sides of the building unit according to the invention partially or completely, the said load-bearing columns preferably comprise one or more load-bearing profiles that extend lengthwise through the load-bearing columns and that are arranged in such a way that one or more wall elements can be removably inserted.

[42] Such wall elements may be arranged of glass, plastic, concrete, Gyproc boards, sandwich panels or any other suitable material. Furthermore, windows and doors may also be included in these walls.

[43] The major advantage thereof is that the building unit can be filled up entirely modular, depending on the user's requirements. Therewith, the position of the doors and windows can be determined itself.

[44] In a preferred embodiment of a building unit according to the invention, the ^! said lower frame at the bottom side thereof comprises at least 4 height-adjustable feet that are applied on each of the 4 corners of the lower frame.

[45] These height-adjustable feet take care that the building unit can be aligned completely horizontally after construction, even on uneven surfaces.

[46] The said lower frame preferably comprises two further height-adjustable feet at the bottom thereof. More preferably, these two height-adjustable feet are located centrally on opposite sides of the lower frame. Most preferably, they are located directly opposite one another. These two further height-adjustable feet are particularly important when building units are stacked on top of one another. This allows the building unit that is on top to stand more stably on the building unit underneath. Moreover, the lower frame and the floor plate in it can then sustain greater loads because the two further height-adjustable feet give a better weight distribution. [47] The number of height-adjustable feet therewith depends on the dimensions and the weight of the building unit, and consequently also whether or not building units are not stacked on top of each other.

[48] The said metal frame is preferably manufactured out of steel since steel is a material that is highly resistant to wind loads and surface loads.

[49] Optionally, the building unit may comprise one or more of the following functional elements within the space delimited by the upper frame and on the side of the upper frame that is on the inside of the building unit when it is assembled:

centrally one or more rails within which lighting is fitted;

one or more removable ceilings;

one or more heating and ventilation elements; and

one or more fixed elements for hanging up objects.

[50] In a second aspect of the invention, a method is provided for assembling a building unit according to the invention as described above, wherein the method comprises the following steps:

positioning the said load-bearing columns at the correct place with respect to the lower frame by inserting the said protrusions into the said corresponding recesses in such a way that the one or more openings arranged in the end of the respective load-bearing column connect against the one or more corresponding openings that are arranged in the lower frame;

partially tightening the releasable threaded connection;

positioning the said upper frame at the correct place with respect to the said placed load-bearing columns by inserting the said protrusions into the said corresponding recesses in such a way that the one or more openings that are arranged in the ends of each load-bearing column connect against the corresponding one or more openings that are arranged in the upper frame;

releasably connecting the load-bearing columns with the upper frame by fully tightening the said screw connection; and

fully tightening the said releasable threaded connection between the load-bearing columns and the lower frame. [51] According to a second aspect of the invention, a method is provided for assembling a unit construction system that comprises one or more disassemblable building units according to the invention as described above.

[52] Such a unit construction system according to the invention is particularly suitable for use as a temporary stand construction for trade fairs and other events, but can equally well be used as temporary space for offices and businesses, catering sector establishments, housing, healthcare, shops, sports halls, schools and childcare facilities, and so forth. These unit construction systems can be used both indoors and outdoors.

[53] In an advantageous embodiment of a unit construction system according to the invention, the unit construction system comprises two or more of the said building units that are placed against one another, wherein the upper frame of the said building units at the upper side thereof comprise a water-retaining rim that extends around the outer edge of the upper frame and wherein between the water-retaining rims of two adjacent building units a covering rubber is applied.

[54] This means that no water can penetrate between two adjacent building units.

[55] To clarify the features of this invention further and to point out additional benefits and special aspects thereof, a more detailed description follows of a built-on or built-in profile system according to the invention. It should be evident that nothing in the description that follows may be interpreted as a limitation on the scope of protection claimed in the claims for a built-on or built-in profile system according to the invention.

[56] In this description, numerical references are given to the enclosed figures, wherein:

• Figure 1 shows a schematic exploded view of a preferred embodiment of a building unit according to the invention;

• Figure 2 shows a schematic side view of the metal frame of a preferred embodiment of a building unit;

• Figure 3 shows a detailed drawing of the connection between a load-bearing column and the lower frame of a preferred embodiment of a building unit;

• Figure 4 shows a schematic side view of a load-bearing column of a preferred embodiment of a building unit; • Figure 5 shows a schematic side view of a load-bearing column that has a drainpipe for precipitation;

• Figure 6 shows a schematic side view of a unit construction system comprising three building units according to the invention;

• Figure 7 shows a schematic side view of a building unit according to the invention that has a load-bearing column that may be telescoped in and out.

[57] On the figure 2, the basic structure of the metal frame (10) of a preferred embodiment of a building unit according to the invention is shown. The metal frame (10) is preferably manufactured out of steel. This metal frame (10) comprises in its most general form a lower frame (2), an upper frame (3) and at each of the 4 corners of these frames (2, 3), a load-bearing column (4a, 4b, 4c, 4d) releasably connected to each of these frames (2, 3). In this way, a building unit (1) is obtained with a dismountable metal frame (10). The lower frame (2) therefore thus acts as floor frame and the upper frame (3) acts as roof frame.

[58] As can be seen in figures 1 and 2, both the lower and upper frames (2, 3) are rectangular in this preferred embodiment. The lower and upper frames (2, 3) therewith comprise an outer frame (21 , 31 ) that consists of 4 lateral girders (211 to 214; 311 to 314), i.e. two long lateral girders (211 , 213, 311 , 313) and two short lateral girders (212, 214; 312, 314). These lateral girders (211 to 214; 311 to 314) are preferably U-shaped profiles lying on one side with the open end of the U facing inwards.

[59] As can be seen in figure 2, these lateral girders (211 to 214; 311 to 314) are provided with passages (17) in order to bolt different adjacent building units (1) to each other by means of a releasable bolt connection.

[60] Within this outer frame (21 , 31), a number of toad-bearing girders (221, 222, 321 , 322) are placed that are connected to the outer frame (21 , 31 ). As can be seen in figures 1 and 2, these load-bearing girders (211 to 214; 311 to 314) are preferably cuboid-formed and they are fitted into the cavity created by the U of the U-shaped lateral girders (211 to 214; 311 to 314). These load-bearing girders (211 to 214; 311 to 314) are therewith preferably welded fixed to the respective lateral girders (211 to 214 and 311 to 314). There exist both load-bearing girders that extend in the length direction of the lower, respectively the upper frame (2, 3) and consequently are placed parallel to the long lateral girders (211 , 213; 311, 313), i.e. the load-bearing girders (221 , 321 ), as well as load- bearing girders that extend in the cross direction of the lower, respectively the upper frame (2, 3) and consequently are parallel to the short lateral girders (212, 214; 312, 314), i.e. load-bearing girders (222, 322). In this way, the load-bearing girders (221 , 321 ) that are extending in the length direction of the lower, respectively the upper frame (2, 3) are perpendicular to the load-bearing girders (222, 322) that extend in a cross direction of the lower, respectively the upper frame (2, 3).

[61] As can be seen in figure 2, at the upper side of the outer frame (21 , 31 ) of the lower as well as the upper frame (2,3), a collar (23, 33) is provided that extends at least partially and preferably wholly, as is the case in this preferred embodiment, around the lower, respectively the upper frame (2, 3). The load-bearing girders (221, 222; 321 , 322) are placed inside the outer frame (21 , 31) of the lower, respectively the upper frame (2, 3) in such as way that the said collar (23, 33) is located above these load-bearing girders (221 , 222, 321 , 322). Because in this preferred embodiment the lateral girders (211 to 214 and 311 to 314) have an U-shape, the said collar (23, 33) is here formed by the upper side of these U-shaped lateral girders (211 to 214 and 311 to 314). As can be seen in figure 2, one or more floor plates (5) are applied within the space delimited by this collar (23, 33) and supported also by the load-bearing girders (221 , 222, 321, 322). These floor plates (5) may consist out of a single piece or multiple pieces. In this preferred embodiment, a floor plate (5) is used consisting out of a single piece. These floor plates (5) are preferably fixed to the lower, respectively the upper frame (2, 3) by means of a screw connection (not shown on the figures). In this way, the floor plates (5) can be removed back from the respective frames (2, 3). On figure 1 , only the floor plate (5) that has been attached to the lower frame (2) is shown. The floor plate that is attached to the upper frame (3) is not shown.

[62] As can be seen in figures 4 and 5, the said load-bearing columns (4a - 4d) in this preferred embodiment have a square cross-section (see figures 4 and 5). It is however also possible to provide the load-bearing columns (4a - 4d) with a rectangular crpss- section. In order to allow the building units (1 ) to be placed up against one another and to fit exactly against each other, the load-bearing columns (4a - 4d) and the outer frames (21, 31) of the lower and upper frames (2, 3) have to be arranged in such a way that the load-bearing columns (4a - 4d) do not protrude outside the respective outer frames (21 , 31 ). It is therewith possible to apply load-bearing columns (4a - 4d) that are entirely within the space delimited by the visible outsides of the outer frames (21, 31) (not shown in the figures), or to take care that the visible outsides of the load-bearing columns (4a - 4d) and the visible outsides of the lower, respectively the upper frame (2, 3) that are adjacent to one another are substantially in the same plane and thus substantially form a line.

[63] One or more of the load-bearing columns (4a - 4d) preferably comprise a drainpipe (6) for water from precipitation. As shown in figure 1 , in this preferred embodiment of the building unit (1) according to the invention, the load-bearing column (4d) is provided of such a drainpipe (6). This drainpipe (6) extends in the longitudinal direction of this load- bearing column (4d) through the whole length of the load-bearing column (4d). In the floor plate (5) that is placed on the upper frame (3), an opening (not shown in the figures) is consequently provided through which the water from precipitation can pass from where it goes through the drainpipe (6) and is drained through another drain via another passage (not shown in the figures) that has been arranged through the lower frame (2). Moreover, as can be seen in figure 2, in order to be able to catch the water from precipitation, the upper frame (2) that is acting as a roof frame has a water retaining rim (33) on the upper side thereof that runs around the outer edge of the said upper frame (3).

[64] The releasable and invisible connection of the load-bearing columns (4a - 4d) to the lower, respectively the upper frame (2, 3) is in more detail below. As can be seen in figure 1 and figures 4 and 5, each of the load-bearing columns (4a - 4d) is at both ends thereof on two sides thereof that in the assembled (or mounted) state of the building unit (1) are fitted against the lower, respectively the upper frame (2, 6), provided with a number of openings (40). In this preferred embodiment of a building unit (1 ) according to the invention, two such vertically above each other placed openings (40) are arranged. Preferably, inside the hollow space of a load-bearing column (4a - 4d), a reinforcement plate (41) with openings at the same location are provided. The lower and the upper frame (2, 3) are at each of the 4 corners thereof provided with two surfaces (24, 34) perpendicular to one another through which at each of these corners a square recess is formed wherein a respective load-bearing column (4a - 4d) having a corresponding square cross-section can be fitted. In these two perpendicular surfaces (24, 34), the same number of drilled holes (25, 35) are arranged as the ones arranged in the load-bearing columns (4a - 4d). In this preferred embodiment, there are consequently also two openings (25, 35) arranged vertically above each other in the said surfaces (24, 34). These openings (25, 35) are applied in such a way in the said surfaces (24, 34) that these substantially fit to the openings (40) applied in the load-bearing columns (4a - 4b) when the building unit (1 ) is assembled. In this way, a threaded connection, preferably consisting out of a bolt (7) (see figure 3), can be applied throughout each of the rows of openings (25, 35, 40) that are arranged in the reinforcement plate (41), the respective load-bearing column (4a - 4d) and the lower, respective upper frame (2, 3) and that fit against one another.

[65] In order to be able to correctly position the respective openings (40) that have been applied in the load-bearing columns (4a - 4d) with respect to one another in a quick and efficient way, the load-bearing columns (4a - 4d) and the lower and upper frame (2, 3) are provided with one or more protrusions (26, 47) that can be fitted loosely in one or more corresponding recesses (46). These recesses (46) therewith are preferably applied in such a way that they extend in a substantially horizontal plane when the building unit (1) is assembled. In this preferred embodiment of a building unit (1) according to the invention, is in the load-bearing columns (4a - 4c) that do not have a drainage pipe (6) for precipitation water the recess formed by the open end (46) of the load-bearing column (4a - 4c) having a fully enclosed side wall (see figure 4). In this way, a square recess (46) is obtained that extends across the full cross-section of the load-bearing column (4a - 4c). The lower, respectively the upper frame (2, 3) therewith provided on each of the 4 corners at the lower, respectively the upper side thereof with a protrusion in the form of a cuboid plate (26) that can be fitted into the square end (46) of each load-bearing column (4a - 4c) by means of a loose fit. With the load-bearing column (4d) in which a drainpipe (6) for water from precipitation is arranged, at the end of the load-bearing column (4d) that in the assembled state of the building unit (1 ) is situated at the lower frame (2), a cylindrical protrusion (47) (see figure 1) is arranged that can be fitted loosely into a round opening (not shown in the figures) that is provided in the bottom side of the lower frame (2). This cylindrical protrusion (47) has to be hollow since therein precipitation water has to be drained therewith. Preferably, this cylindrical protrusion (47) is the extension of the drainpipe (6) (as can be seen in figure 5).

[66] The metal frame (10) is assembled as follows:

1. positioning the said load-bearing columns (4a - 4d) at the correct places with respect to the lower frame (3) by inserting the said protrusions (26, 47) into the said corresponding recesses (46) in such a way that the one or more openings (40) arranged in the ends of the respective load-bearing columns (4a - 4d) fit against the corresponding one or more openings (25) that are arranged in the lower frame (2);

2. partial tightening of the releasable threaded connection (7);

3. positioning the upper frame (3) at the correct place with respect to the said load- bearing columns (4a - 4d) by inserting the said protrusions (26, 47) into the said corresponding recesses (46) in such a way that the one or more openings (40) arranged in the ends of the respective load-bearing columns (4a - 4d) fit with the corresponding one or more openings (25, 35) that are arranged in the upper frame

(3);

4. connecting the load-bearing columns (4a - 4d) releasably to the upper frame (3) by tightening the said screw connection (7) fully; and

5. tightening the said releasable threaded connection (7) between the load-bearing columns (4a - 4d) and the lower frame (2).

[67] Furthermore, the building unit (1) can be provided with one or more in- and out slideable load-bearing columns (4e), as shown in figure 7. These in and out slideable load-bearing columns (4e) consist of two or more in and out slideable column elements (42, 43). In the embodiment as shown in figure 7, the two outermost column elements (42) and one central column element (43) are provided that ar© set up in and out slideable with respect to one another. Such a telescoping load-bearing column (4e) is consequently removable from the building unit (1 ). In order to assemble such a in and out slideable load-bearing column (4e), the column elements (42, 43) must be slid out of one another until one or more protrusions (26, 47) of the lower and upper frame (2, 3) can be applied loosely into one or more openings (46) of the in and out slideable load-bearing column (4e). Thereafter, the column elements (42, 43) are bolted tightly together using one or more releasable bolt connections (44). In order to disassemble such a in and out slideable load-bearing column (4e) again, the one or more bolted connections (44) must be released again and the in and out slideable load-bearing column (4e) have to be slid out of each other until the one or more protrusions (26, 47) are out of the one or more openings (46) again. Thereafter, the in and out slideable load-bearing column (4e) can be removed from the building unit (1 ).

[68] Providing such removable load-bearing columns (4e) can be desirable when several building units (1 ) are placed next to each other and one or more load-bearing columns are not desired within the space delimited by the various building units (1).

[69] In order to disassemble the metal frame (10), the following steps are taken:

1. the upper frame (3) is hang to lifting chains;

2. the threaded connection (7) between each of the load-bearing columns (4a - 4d) and the upper frame (3) is released and the upper frame (3) is removed from the load- bearing columns (4a - 4d); 3. the threaded connection (7) between each of the load-bearing columns (4a - 4d) and the lower frame (2) is released and the load-bearing columns (4a - 4d) are removed from the lower frame (2).

[70] Because the floor plate (5) during the mounting of the building unit (1) firstly is mounted on the lower, respectively the upper frame (2, 3) and therefore the threaded connection (7) is no longer accessible from above, in the floor plate (5) that is applied on the lower frame (2) at each of the places where a load-bearing column (4a - 4d) is connected with the upper, respectively the lower frame (2, 3), a hatch (50), preferably in the form of a trapdoor, is arranged. In order to consequently tighten in the above described method the threaded connections (7) partially of fully, the hatches (50) must be opened in order to be able to get at the threaded connections (7).

[71] As can be seen in figures 2 and 3, the lower frame (2) is preferably at the inside thereof provided with height-adjustable feet (8). These height-adjustable feet (8) take care that the assembled building unit (1) can be positioned fully horizontally, even on an uneven surface. As can be seen in figure 3, the adjustable feet (8) preferably consist out of a rod (81) with a trapezoidal thread, this in order to be able to place the building unit (1 ) also on sand and gravel. In addition, the adjustable feet (8) have a foot plate (83) (see figures 2 and 3) to prevent that the adjustable feet (8) would sink into a soft surface. A ring (82) is placed over the rod (81) and can move freely over the rod (81). This ring (82) is welded onto the long lateral girders (211 , 213) of the lower frame (2).

[72] Preferably, on each of the corners of the lower frame (2) such an adjustable foot (8) is provided. Furthermore, an extra adjustable foot (8) is preferably arranged in the middle of each of the two long lateral girders (211 , 213). These two extra height- adjustable feet (8) preferably are located directly opposite to one another. When the floor plate (5) is applied on the lower frame (2), then the height-adjustable feet (8) that are arranged at the corners of the lower frame (2) can be reached by means of the hatches (50) described above. Furthermore, also at each of the height-adjustable feet (8) that are situated in the middle of the long lateral girders (21 1 , 213), such a hatch (50), preferably in the form of a trapdoor are arranged.

Γ73] As can be seen in figures 1 and 2, the lower frame (2) preferably is provided with a number of drilled drilled holes (9) into which a lifting eye (not shown in the figures) can be inserted. These lifting eyes have to be placed in such a way that the lower and/or upper frames (2, 3), the metal frame (10) and the entire building unit (1 ) in the assembled state thereof can be lifted using these lifting eyes. More preferably, 4 such drill drilled holes (9) are applied symmetrically to two opposite sides of the outer frame (21 ) and the lower frame (2).

[74] A preferred embodiment of a building unit (1) according to the invention preferably is provided with one or more water supply pipes (not shown in the figures). The outer frame (21 ) of the lower frame (2) therefore comprises one or more passages in order to bring the water supply pipes into the space delimited by the lower frame (2). Furthermore, water supply pipes can be brought through one or more of the said hatches (50) into the space delimited by the said metal frame (10).

[75] In addition, the building unit (1) preferably contains a number of other utilities such as electricity, telephone, television, Internet, video and the like. In order to get these utilities invisibly into the space of the metal frame (10), one or more passage (11 ) preferably are firstly arranged in the outer frame (21 , 31) of the said lower and upper frame (2, 3). In the metal frame (10) as shown in figure 1 , such a passage (11 ) are arranged in each of the short lateral girders (212, 214, 312, 314) of both the lower and upper frame (2, 3), while in the metal frame (10) as shown in figure 2, only in the short lateral girders (212, 214) of the lower frame (2) such a passage (11) is arranged. The said cables for the utilities are preferably applied through one or more of the hollow load- bearing columns (4a - 4d). As can be seen on figures 1, and 3 to 5, therefore in the said load-bearing columns (4a - 4d), and in the lower and upper frame (2, 3) at the place where the said load-bearing columns (4a - 4d) are releasably connected with the lower, respectively the upper frame (2, 3), one or more passages (12) are provided for passing in these cables for utilities inside the respective hollow load-bearing columns (4a - 4d). Furthermore, a number of passages (16) can be arranged in the outer frame (21, 31) of the upper and/or lower frame (2, 3) themselves for passing in cables for utilities,

[76] As can be seen in figures 1 to 3, the lower and upper frame (2) are preferably provided with U-shaped rails (13) into which one or more wall elements (not shown in the figures) can be inserted removable again. These wall elements are consequently modularly applicable, this as desired by the user of the building unit (1 ). The U-shaped profiles (13) permit to easily change the wall elements and to remove these back out of the metal frame (10). [77] As can be seen in figure 1, one or more removable ceiling panels (14) can preferably be arranged within the space delimited by the upper frame (3). These removable ceiling panels (14) are preferably be arranged as a hanging ceiling (14) that can be fitted removably in a system of guide grooves (not shown in the figures) that is tied to the upper frame (3). These hanging ceilings (14) preferably are arranged out of textile that around the edge thereof is provided with is provided with a silicone edge that can be fitted removably again into the respective guide grooves.

[78] Moreover, in the preferred embodiment of a building unit (1) according to the invention as shown in figure 1 , a rail (15) that is connected to the upper frame (3) has been arranged centrally inside the space delimited by the upper frame (3). This rail (15) is preferably attached to the upper frame by means of screws. It is also possible to provide several such rails (15). In these rails (15), various functionalities can be built in. For example lighting can be brought in.

[79] Furthermore, a building unit (1) according to the invention can also contain other elements arranged within the space delimited by the upper frame (3), such as heating and ventilation elements, fixed hanging points for hanging up objects and the like.

[80] The building units (1) according to the invention can have various dimensions. They preferably have a dimension such that the lower and upper frame (2, 3) can be transported on a trailer of a truck. Various such building units (1) then can be joined together optionally in a modular way into a unit construction system (100). This unit construction system (100) can consist out of building units (1 ) that are placed adjacent to one another as well as the one on top of the other. On figure 6, such a unit construction system (100) is shown consisting of three building units (1), of which two are next to each other and two are on top of each other. The height-adjustable feet (8) take care that the building units (1 ) can be very easily placed on top of each other and can be horizontally levelled.

[81] When building units (1 ) are placed on top of another, the unit construction system (100) can include one or more stairs (not shown on the figures).

[82] If a unit construction system (100) consisting out of two or more building units (1) placed next to each other is installed outdoors, it may be opportune to take care that no water from precipitation can penetrate the building units (1 ) that are placed next to one another. To that end, between adjacent water retaining rims (33), a covering rubber (not shown in the figures) can be applied.