Abstract:
A multi-floor building construction system for progressively constructing floors on load-bearing means of a foundation as the occupational need to do so arises and while sub-floors can be occupied. A permanent roof structure is displaceably supported over an uppermost floor of at least an upper one of one or more occupational floor spaces. Extensible load support means is secured in the roof structure until the completion of the mufti-floor building. The extensible load support means rests upon the uppermost floor to support the total load of the permanent roof structure. The extensible load support means is extendible downwardly to push against the uppermost floor to raise the permanent roof structure. Adjustable hoisting means is secured inside the permanent roof structure for lifting floor sub-assemblies fabricated in the construction zone using the extensible load support means while simultaneously raising the permanent roof structure.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application is a National Phase of International application No. PCT/CA2010/000161, filed Feb. 5, 2010, which claims priority on U.S. provisional patent application no. 61/150,813 filed on Feb. 9, 2009. 
    
    
     TECHNICAL FIELD 
     The present invention generally relates to the construction methods for multi-floor buildings and specifically to a multi-floor building construction system and method for progressively constructing floors on a foundation as the occupational need to do so arises while allowing previously constructed floors to be occupied. 
     BACKGROUND ART 
     Construction projects of multi-floor and tall buildings are becoming more and more important in terms of number of floors, number of employees involved in their construction, the financing requirements and the impact such projects have on the urban life of the project neighborhood. 
     Many construction projects are completed in regions where weather conditions have a direct impact on workers productivity and security. The contractors also need to respect codes and standards for environment, safety and ergonomics that apply with increasing rigor. The traditional construction method poses real challenges when it comes to vertical transportation of the materials and workers. Working high on open structures, using tower cranes and boom lifts handling materials up in the air represent a major source of incidents, injuries and even death of employees on a regular basis. Tower cranes also represent significant cost charges for taller buildings. Furthermore, the control of an open work environment is complex and difficult to maintain. 
     A fair amount of construction projects for multi-floor buildings are held by a lack of sufficient financing or a lower leasing ratio than expected. Those constraints are even more important and regular during difficult economical times where the initial leasing ratio target often increases in order to reduce the risk associated with long term financing. Other projects highly desirable on a long term time scale are impossible to realize with the conventional method because of the impact they would have in high density urban area or other specific area very sensible to the impacts of such projects. The current construction methods are not flexible and very sensitive to changes and unpredictable situations that may arise during the project, sometimes affecting very badly the project profitability. The owners and contractors have no flexibility on schedule and project scale when it comes to adapting to a sudden specific situation. So far, construction projects methods only allowed occupancy after substantial completion of the construction, which delays significantly the revenues and affects the project financial balance. The investments are so important for taller buildings that only a very small group of selected contractors and owners can consider such projects. Even with the best planning, large construction projects still represent important risks for those responsible for their completion. 
     SUMMARY OF THE INVENTION 
     The system of the present invention includes a permanent roof structure equipped with multiple means for vertical displacement, such as extensible load support means, secured in said permanent roof structure. The multiple extensible load support means are synchronized and controlled to allow the permanent roof structure to be lifted in order to create a secure and protected construction zone, under the permanent roof structure, for at least one additional occupational floor to be built. The permanent roof structure can be lifted to create new construction zone as lower floors are completed and occupational need to do so arises. In order to provide the construction zone with the required materials, components, tools and workers, one or multiple means of vertical transportation and material handling, such as dedicated high capacity freight elevators are also part of the system. Such material handling means will allow construction to occur without affecting occupants of the building, its surroundings and its neighborhood and will avoid public space occupancy that typically occurs during conventional building construction. Vertical transportation of occupants is achieved with dedicated extensible elevators having the suspension and electric cables accumulated and available for future extension. 
     To secure the construction zone, the permanent roof structure is equipped with a wall enclosure system. The wall enclosure shields the construction zone on its entire perimeter, eliminating losses due to inclement weather conditions and protecting workers and neighborhood from the risks associated with the conventional method of construction. The disclosed construction system also incorporates adaptations to the elevators, and the mechanical and electrical systems of the building to allow their extensions when adding occupational floors without affecting services to the completed occupational floors below the construction area and to provide continuous services to the permanent roof structure and to workers in the construction zone. 
     The permanent roof structure is also equipped with adjustable hoisting means, such as manually installed hooks, that will allow workers to hook and locate the construction material and components sub-assembly they are completing at the most ergonomic and comfortable height, variable for any tasks of the assembly. For example, the sub-assembly of all the horizontally oriented conduits and components for plumbing, electrical, fire protection and other systems are completed at optimal ergonomic and productive heights. When electrical and mechanical horizontal conduits are assembled, the extensible load support means lift the permanent roof structure and the hooked construction sub-assembly to allow the installation of a temporary or permanent load supporting means for the construction sub-assembly. This allows to pour concrete, when applicable, fabricate the interior divisions, install vertically oriented construction materials and connect the resulting vertical sub-assembly to the horizontal construction sub-assembly above which will lead to the completion of the construction of the new occupational floor. For concrete constructions, the extensible load support means are retracted back in the permanent roof structure before the concrete is poured. The construction sub-assembly can be supported by temporary load support means that are also used as concrete forms to pour concrete. The temporary load supporting forms are equipped with a top interface that is capable of supporting the construction sub-assembly and provide the next attachment points for the base of the extensible load support means. The extensible load support means retracts inside the temporary load supporting forms and are re-attached on the top portion of the temporary load supporting forms using interface elements. An alternate location of the extensible load support means could be offset from the permanent load supporting means of the building when the building structure is designed accordingly. 
     The system and method of the present invention provides several features and advantages such as providing more flexibility in the construction project management by offering the possibility to add floors as the occupational need to do so arises, within a given pre-determined number of floors range. It also reduces the initial financing requirement by allowing to lease the first lower floors as soon as they are completed without waiting for the complete building to be constructed and therefore preempt revenues much sooner in the project cash flow. 
     The present invention also increases flexibility in the project management by allowing more work to be done in factory and by offering the possibility to sub-divide the work schedule into smaller work lots and therefore increase the competitiveness of subcontractors offer. It also facilitates the human resources management for contractors by leveling the work load, reducing the amount of interruptions, reducing overtime and giving the possibility to work on multiple smaller projects simultaneously instead of only a few very large projects and be impacted by their variable schedules. 
     The invention further improves health and safety conditions and the quality of the craftsmanship by improving the work environment, independent from outside weather conditions, by providing much better ergonomics at work and by reducing the use of high risk equipment such as tower cranes, boom lifts, ladders and scaffoldings. 
     The invention also increases the productivity by allowing to complete the structural work of a new floor while standing on the floor and then locate the construction sub-assembly at the desired height for best ergonomic position during the balance of the assembly work. 
     The invention further reduces or eliminate inconveniences that large urban construction sites impose by concentrating and optimizing trucks unloading, material storage and material vertical transportation inside the building or a controlled area, and therefore allowing to restore building neighborhood much more quicker than for projects with conventional methods and to reduce charges for public occupancy. It also increases post-construction building efficiency for renovation projects, client relocation, or any other situation in the building life that requires efficient vertical material handling and isolation of construction area. 
     According to a broad aspect of the present invention there is provided a multi-floor building construction system for progressively constructing floors on load-bearing means of a foundation as the occupational need to do so arises and while sub-floors can be occupied. The system comprises a permanent roof structure of any desired architectural shape displaceably supported over an uppermost floor of at least an upper one of one or more occupational first floor space constructed over the foundation. Extensible load support means is secured in the roof structure and adapted to rest upon and push against the uppermost floor to support a total load of the permanent roof structure. Means is provided to operate the extensible load support means in synchronization to elevate the permanent roof structure to create a construction zone over the uppermost floor of the building structure where an occupational floor space is to be constructed under the permanent roof structure with the permanent roof structure held elevated from the uppermost floor by the extensible load support means. Means is also provided to transport construction materials within dedicated and enclosed spaces isolated from the occupational floor spaces. Occupant services providing means is adapted to the further occupational floor space and integrated with existing occupational floor spaces. 
     According to a further broad aspect of the present invention there is provided a method of constructing a multi-floor building progressively, floor-by-floor, by adding floors above an uppermost occupational space as the need to do so arises and while sub-floors can be occupied. The method comprises the steps of providing a load-bearing floor with load-bearing means. A permanent roof structure is constructed over the load-bearing floor. Extensible load support means is secured in the permanent roof structure and aligned to rest upon or in close proximity to at least some of the load-bearing means to support a total load of the permanent roof structure. The extensible load support means is adapted to be operated in synchronization. The permanent roof structure is lifted a predetermined distance above an upper occupational floor space to create a construction zone above the occupational floor space to construct one or more additional occupational floor spaces as the need to do so arises. Material is provided to the construction zone with at least one vertical transportation means displaceable in a dedicated enclosure isolated from the occupational floor space. Occupant services are provided to the one or more additional occupational floor spaces and integrated with existing occupational floor spaces. 
     The method further comprises at least one extensible occupants elevator being extended as the demand to do so arises using the extensible load support means or another lifting means to locate the mechanisms of the elevator and release suspension and electric cables to accommodate the new extended stroke or travel. 
     According to a still further broad aspect of the present invention there is provided a business method of constructing a multi-floor building comprising constructing a permanent roof structure over a foundation and elevating the permanent roof structure a predetermined distance over an occupational floor space thereunder as the occupational need to do so arises upon the pre-sale of at least portions of a further occupational floor space to obtain the financing to construct the further occupational floor space. The permanent roof structure remaining on the multi-floor building when completed. 
    
    
     
       BRIEF DESCRIPTION OF TABLES AND DRAWINGS 
       A preferred embodiment of the present invention will now be described with reference to the accompanying drawings in which: 
         FIG. 1  is an overall side view of a tall multi-floor building, built using the disclosed method and system of the present invention, showing the construction zone over the previously constructed, completed and occupied floors; 
         FIG. 2  is a side view illustrating a construction sub-assembly being raised for the installation of the temporary load supporting forms; 
         FIG. 3  is a fragmented side view of the high capacity and extensible freight elevator or occupants elevator; 
         FIG. 4A  is a fragmented side view of the driving means of an extensible freight elevator in position to feed the construction zone; 
         FIG. 4B  is a side schematic view of a mobile upper traction drive mechanism for the extensible occupants elevators; 
         FIG. 4C  is a side schematic view of a base mounted traction drive mechanism for the extensible occupants elevators; 
         FIG. 5  is a fragmented side view of the permanent roof structure lifting the support frame of an elevator drive mechanisms for its extension; 
         FIGS. 6A and 6B  are side views of an unloading dock equipped with dock lift to unload trucks efficiently; 
         FIGS. 7A to 7C  are top and side views of a concept of temporary high capacity and extensible freight elevator and unloading dock located in a controlled area on the perimeter of the building and accessing the construction zone underneath the wall enclosure; 
         FIGS. 7D to 7F  are top and side views of a concept of temporary high capacity and extensible freight elevator and unloading dock located in a controlled area on the perimeter of the building and accessing the construction zone from outside and through the wall enclosure; 
         FIG. 8  is an enlarged fragmented side view of a detail for the adjustable hoisting means able to hook a construction sub-assembly to the permanent roof structure; the adjustable hoisting means are also capable to support the permanent roof structure onto the construction sub-assembly when the construction sub-assembly sits on the floor, to allow the extensible load support means to be retracted; 
         FIG. 9  is a fragmented side view illustrating the manual operation and installation of the adjustable hoisting means to attach it to the construction sub-assembly; 
         FIG. 10  is a fragmented side view illustrating a permanent retractable wall enclosure constructed with rigid panels and an example of an anchoring method to the building; 
         FIG. 11A  is a view similar to  FIG. 10  of an alternate permanent retractable wall enclosure constructed with a heavy-duty tarpaulin, single or multiple layers, attached to a lower rigid platform anchored to the building; 
         FIG. 11B  is an enlarged fragmented side view of an example of a temporary wall enclosure assembled with multiple removable structures or panels secured to the permanent roof structure; 
         FIG. 11C  is a view similar to  FIG. 11B  illustrating a temporary wall enclosure assembled with multiple removable and telescopic structures or panels secured to the permanent roof structure and the building; 
         FIG. 12  is a fragmented side view of an example of an arrangement for the extensible load support mean of the permanent roof structure; 
         FIG. 13  is a side view of a synchronization means for the extensible load support means, herein a drive shaft with universal joints; 
         FIG. 14  is perspective view of an extensible load support means constructed by upside down telescopic tubular thrust screws to allow for a compact drive mechanism; 
         FIG. 15  are side and end views of an alternate extensible load support means constituted by upside down push-pull chain with chain storage inside the permanent roof structure; 
         FIG. 16A  and  FIG. 16B  are side views with accompanying top views of an example of fabrication for the temporary load supporting forms having a removable temporary lower portion and a permanent top portion remaining in the concrete; 
         FIG. 16C  is a plan view of a typical arrangement when extensible load support means are aligned with permanent load supporting means of the building; 
         FIG. 16D  is a plan view of a typical permanent roof structure with an adaptation when extensible load support means are offset from permanent load support means of the building; 
         FIG. 17A  is a schematic side view of an example of a foundation with an architecturally shaped permanent roof structure installed and ready to be lifted to create a first construction zone; 
         FIG. 17B  is a further schematic side view of an example of a foundation with an architecturally shaped permanent roof structure installed and ready to be lifted to create a first construction zone; 
         FIG. 17C  is a schematic side view of an example of a divided permanent roof structure to accommodate a change of geometry or surface at a given storey or floor level; 
         FIG. 18  is a fragmented side view of a position A of the permanent roof structure in the construction process; the permanent roof structure is in its lowest position of the sequence, sitting on the last constructed floor; 
         FIG. 19  is a fragmented side view of a position B of the permanent roof structure in the construction process; the permanent roof structure is raised to free space for the workers that work on a new construction sub-assembly; 
         FIG. 20  is a fragmented side view of a position C of the permanent roof structure in the construction process; the permanent roof structure has been lowered to allow a manual installation of the adjustable hoisting means and hook the construction sub-assembly to the permanent roof structure; 
         FIG. 21  is a fragmented side view of a: Position D of the permanent roof structure in the construction process; the permanent roof structure has been raised from position C to set the construction sub-assembly at the desired height to complete the assembly work of mechanical and electrical systems, conduits, boxes, etc.; 
         FIG. 22  is a fragmented side view of a position E of the permanent roof structure in the construction process; the permanent roof structure has been raised from position D to allow workers to install the temporary load supporting forms or permanent columns to support the construction sub-assembly; 
         FIG. 23  is a fragmented side view of a position F of the permanent roof structure in the construction process; the permanent roof structure is lowered from position E onto the temporary load supporting forms or permanent columns for attachment; this will allow to pour the concrete of the new slab and filling of the temporary load supporting forms if applicable (concrete structure); 
         FIG. 24  is a fragmented side view of a position G of the permanent roof structure in the construction process; the completed construction sub-assembly sits in its final position after the new concrete slab has been completed; the extensible load support means have been retracted prior to concrete work; the guiding device and permanent retractable wall enclosure has been raised and reattached one floor higher on the building; 
         FIG. 25  is a fragmented side view of a position H of the permanent roof structure in the construction process; the permanent roof structure is lifted by the extensible load support means and lifts the frame supporting the drive mechanisms of the elevators while guiding them laterally; the structure of the elevator shaft is extended and new bumpers for the drive frame are installed to sit the frame in its new, raised, location; and 
         FIG. 26  is a fragmented side view of a position I of the permanent roof structure in the construction process; the permanent roof structure is lowered and sits on fixed bumpers, attached to the building, and waiting for the next construction phase to begin. 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     Vertically Displaceable Permanent Roof Structure 
     Referring now to the drawings, the present invention will be described. A permanent roof structure  1  is first assembled on a foundation  48  for the building construction. The shape of the foundation  48  needs to be similar to the shape desired for the floors to build in the future. The permanent roof structure  1  can have any shape, as long as it extends equal to or greater than the desired shape of the floor to build in the future. 
     The permanent roof structure  1  includes a structure  5  similar to those of conventional roof assemblies. The permanent roof structure  1  is moveable vertically using extensible load support means  6  that are motorized, synchronized and controlled. In order to add a floor when the occupational need to do so arises, the permanent roof structure  1  is raised to create a construction zone  3  under the permanent roof structure for at least one additional floor. Examples of extensible load support means  6  are shown in  FIGS. 14 and 15 . Any synchronizable extensible load support means can be used to lift the permanent roof structure  1  at pre-determined heights as long as it provides sufficient stroke and lifting force. A synchronization means  8 , such as the one shown in  FIG. 13 , mechanically link all the extensible support means  6 . The extensible load support means  6  can be synchronized electronically. The extensible load support means  6  are also linked to gearboxes, not shown, that are selected for proper speed and torque of each specific application. To complete the drive mechanism, electrical brake motors  9  are added to provide driving force to the mechanism. The drive mechanism comprising the motoring element such as an electrical brake-motor, the extensible load support means  6  and the synchronization means  8 , have a support base secured, up side down, in the permanent roof structure  1  as shown in  FIGS. 2 and 12  to provide an upward pushing force on the roof structure. The extensible load support means  6  are located either in-line with some identified supporting element  37  of the foundation  48  or close to the foundation  48  supporting element  37  or at any location capable of supporting the extensible load support means  6  and total load said extensible load support means  6  are supporting. 
     The extensible load support means  6  are normally supported on an interface element  11  that sits directly on the last floor constructed or can even be embedded in the concrete slab and remain there permanently. For concrete structures, the interface elements  11  have sufficient openings that allow concrete to flow through to fill the temporary load support forms  35  with the re-bars  51  inside. The interface elements  11  are specifically designed for each project and also incorporate vibration dampers (not shown) to reduce vibration transmission from the driving mechanism of the permanent roof structure  1  into the building structure and reduce noise, if required, to the occupied floors thereunder. 
     The permanent roof structure  1  is equipped with electrical power, lighting, heating, compressed air, and fresh water supply and has multiple outlets as required in any construction site. These services to the permanent roof structure  1  are permanently connected to the building services through valves, flexible conduits and cable trays. 
     Control System and Electrical Power 
     The control system of the permanent roof structure  1  includes at least one control panel  10  housing a programmable logic control element and electrical control relays where all the safety interlocks and operation interface are connected to control the operation of the permanent roof structure  1 . The control panel  10  is located at any safe and convenient location and can be wired with extensible cables (not shown) or through a cable tray (not shown) if required. The electrical brake-motors are connected to power disconnect junction boxes (not shown). Permanent junction boxes (not shown) are located on the last floor  34  in any required location to allow electrical connections and continuity. An interface panel (not shown) is provided to the operator to communicate any fault during the operation. The permanent roof structure  1  also incorporates all the safety devices required for a safe operation (visual warnings, audible warnings, interference detectors, stroke limit switches . . . ) (not shown). 
     Adjustable Hoisting Means 
     The permanent roof structure  1  is equipped with adjustable hoisting means  13  as shown in  FIGS. 2 ,  8  and  9 . There are multiple adjustable hoisting means arranged to cover the complete surface of the building floor to distribute the load of the construction sub-assembly  44  as required over the entire permanent roof structure  1 . 
     When beginning the construction, a new construction sub-assembly  44  is assembled on the foundation  48 , or the last floor constructed  34 . The construction sub-assembly  44  incorporates all the construction materials and components of a typical building floor, without the vertical elements. The adjustable hoisting means  13  purpose is first to hook the construction sub-assembly  44  to the permanent roof structure  1  in order to synchronize the vertical movement of the construction sub-assembly  44  to the extensible load support means of the permanent roof structure  1 . Second, the purpose of the adjustable hoisting means  13  is to act as a bumper to support the permanent roof structure  1  onto the construction sub-assembly  44 , when the construction sub-assembly  44  sits on last floor  34 , during the time that the extensible load support means  6  are retracted into the permanent roof structure  1  to be reattached on the top portion of the temporary load supporting forms  35 . 
     The adjustable hoisting means  13  comprise adjustment means  15  and  16  to adapt to normal construction variations. The end  17  is attached to the construction sub-assembly  44  with a positive fixation method, such as bolts and safety pins, not allowing separation if impacted by an interfering object. The length of the adjustable hoisting means  13  is specific to each application. 
     The adjustable hoisting means  13  allow the workers to adjust the height of the construction sub-assembly  44 , as it is desired, at any stage of the construction work, using the extensible load support means  6  of the permanent roof structure  1 . This allows the workers to work at the best ergonomic and most productive heights during the construction work, for example when assembling horizontal conduits of plumbing, ventilation conduits, and electrical wires. It also allows the operator of the permanent roof structure  1  to lift, once completed, the construction sub-assembly  44  to a pre-determined height to allow the installation of the permanent building columns or temporary load supporting forms  35  when building a concrete building structure. 
     Guiding Device 
     The permanent roof structure  1  must remain aligned and stable during vertical movement using a guiding device. The guiding device is a novel arrangement of some of the already known guiding elements such as scissors (not shown), lambdas  12  (see  FIG. 2 ), telescopic bars (not shown) or any element attached to the permanent roof structure  1  and following, by friction or rolling, a structural element, such as an extensible central structural core  38  (see  FIG. 4A ) serving as an elevator shaft of the building. Collapsing guiding element such as scissors and lambdas  12  can be attached to the last floor  34 . 
     The guiding device purpose is to counteract any external lateral forces that could potentially move the permanent roof structure  1  laterally if it was unguided. Such lateral forces include wind, seismic forces and others. When there is no construction work, the permanent roof structure  1  is attached to the building through positive fixation and the permanent roof structure  1  sits directly on the interface elements  11  that are then used as bumpers and anchor blocks. 
     Wall Enclosure 
     As shown in  FIGS. 10 to 11C , a permanent retractable wall enclosure  18  shields the construction zone  3  under the roof from inclement weather conditions and prevents objects from falling off the construction zone  3  of the building. The permanent retractable wall enclosures  18  defines a working space  72  peripheral to the construction zone  3  and the building  34  in order to provide more space for the construction work to occur. This space being larger than the construction zone  3 , it also allows easier assembly of the building envelope components  45  and  46 . The working space  72  is supplied by a peripheral material handling mean  71  comprising a linear support mean that can carry multiple types of trolleys, trays, bins and other material handling devices (not shown). 
     The permanent retractable wall enclosure  18  can be self motorized or anchored on the last floor  34  and extend or retract following the movement of the permanent roof structure  1  driven by the extensible load support means  6 . The permanent retractable wall enclosure comprises a wall either constructed with articulated rigid panels, such as shown in  FIG. 10 , or accumulating like an accordion, or a membrane  20  accumulating on a drum  21 . The membrane  20  is made of resistant material and can be multi-layer when required. At the base of the permanent retractable wall enclosure  18  and  20  is a rigid platform  19  accessible to workers. The rigid platform  19  is safely attached to the building by a positive fixation means  22 . The permanent retractable wall enclosures  18  and  20  can be equipped with windows to provide natural lighting to the construction zone  3 . 
     The temporary wall enclosure as shown in  FIG. 11B  shields the construction zone  3  similarly to the permanent wall enclosure  18  but it can be removed once the building has reached its final elevation. The temporary wall enclosure comprises a retractable rigid platform  67 , multiple adjustable rigid platforms  66  accessible to workers or for construction materials, multiple exterior shell sections  65 , upper retractable supporting members  64  to secure the exterior shell sections  65  to the permanent roof structure  5 , sealing components (not shown) and a removable device (not shown) to easily and safely remove the panels once the construction is complete. The temporary wall enclosure is assembled early in the construction process, after the completion of the permanent roof structure  1 . Once assembled, it is at least partially rigid and fixed to the permanent roof structure  1  and therefore follows the same vertical displacement during construction. The exterior shell sections  65  are similar to each other except for corner elements (not shown) that are fitted to the building dimensions. An alternate concept could also use telescopic exterior shell sections as shown in  FIG. 11C  wherein the bottom sections could have the platform  67  attached to the building. Another alternate concept could use the vertical displacement of the permanent roof structure  1  for the removal of the exterior shell sections  65  instead of a specific removal device (not shown). 
     High Capacity Vertical Transportation Means 
     One or multiple high capacity vertical transportation means, such as a permanent dedicated high capacity freight elevator  24 , internal or peripheral to the building, are accessible from the first basement or ground level and allow construction material and components to be transported efficiently to the construction zone  3 . The building is equipped with an access ramp  39  that trucks  43  use to unload merchandises, materials and components at a dock  42  or a transfer deck  69  equipped with handling equipment such as a dock lift  41 , jib cranes and other equipment. Materials and components are transported to a permanent high capacity freight elevator access  40  using standard material handling equipment such as forklift trucks (not shown). 
     The high capacity vertical transportation means,  FIGS. 3 and 4A , is installed at the same time as the permanent roof structure  1 , on the building foundation  48 , in order to be useful at the very early stage of the building construction. The load capacity, the speed and the size, are project specific. The permanent high capacity vertical transportation mean  24  includes a frame support  23  supporting the drive mechanism components comprising a motoring assembly  29 , pulley systems  27 ,  30  and  31 , a cable accumulation drums  26  and  28 , a set of supporting bumpers  32 , a counter weight  35 , a cage  24  and any other components (not shown) to respect applicable standards. 
     As shown in  FIG. 4A , the supporting frame  23  normally sits in a set of support bumper  32  attached to the building structure  38 . In order to extend the building structure  38 , a set of catcher  33 , part of the structural element  5  of the permanent roof structure  1 , picks up the frame  23  to raise it at a pre-determined height, as the permanent roof structure  1  is lifted by the extensible load support means  6 . Said catcher  33  could also be part of the support frame  23  in order to be operated from the elevator equipment. 
     When adding a floor to the building, the effective stroke of the permanent vertical transportation mean  24  needs to be adjusted by adapting the control system such as changing a register in the program of the programmable logic controller (not shown), by extending the guide rails (not shown), by relocating the travel limit switches (not shown). To extend cables, it is possible to secure the cage  24  to the building structure  38  with pins or bumpers (not shown). The extra cable required has to be already available on an accumulation drum  26  (see  FIG. 3 ) that is normally locked, but is released during the operation of lifting the frame  23 . While frame  23  is lifted by the extensible load support means  6  of the permanent roof structure  1 , the accumulation drum  26  releases the amount of cable required for the cage  24  additional stroke. From the beginning of the construction, the accumulation drum  26  needs to store the cable required for the maximum stroke the cage  24  will ever do, otherwise the cable will need to be changed in the course of the construction. 
     The high capacity vertical transportation means can be permanent, temporary, internal or peripheral to the building. An example of a concept for a temporary high capacity transportation means is shown in  FIGS. 7A to 7C  and is a peripheric transportation cage  68  displacing materials vertically from a transfer dock  69 , at unloading level, to the construction zone  3  above, accessing from underneath or from outside a temporary wall enclosure as shown in  FIG. 11B , passing through its platform  67  and stopping within the exterior shell sections  65 , or stopping at an access door on the exterior shell without entering the wall enclosure, as shown in  FIG. 7D to 7F . Such a system allows to unload trucks  43  efficiently to the transfer deck  69  when the peripheric transportation cage  68  is not available. Also, it allows efficient handling of materials once they reach the construction zone  3  where the materials can be transferred to a peripheric materials handling rail  71  for ergonomic materials handling. The drive mechanism of the peripheric transportation cage  68  can use an extensible cable drive as shown in  FIG. 3  to  FIG. 5 , or another suited cable or chain drive, or have at least one drive and guide columns  70  specifically designed for the application. 
     The permanent roof structure  1  is equipped with a covered opening  2  offering sufficient clearance for the vertical movement required during the construction without interfering with the building structure  38 . 
     The permanent vertical transportation mean  24  is also used post-construction to move occupant&#39;s goods or during renovation projects while a temporary system is removed once the construction is completed. 
     Construction and Extension of the Building Structure 
     The new construction system and method described here works well with conventional steel construction method having lightly adapted components and standard connections. The structural components are transported using the permanent vertical transportation mean  24  and material handling equipment, standard or specialized (not shown). The new construction system and method hereby can also use a specific column design where the column is made of at least two components assembled around the extensible load support mean  6 . Finally, the new construction system and method works well with hybrid or concrete building structures where temporary load supporting forms  35  are used to support the construction sub-assembly  44  while the extensible load support mean  6  are retracted to be reattached on top of an open interface element  11  that allows concrete to flow through. 
     For buildings with hybrid or concrete structures, the re-bars  51  installation is complete around the extensible load support mean  6  without preventing it to be retracted further in the construction. The temporary load supporting forms  35  are circumscribing the re-bars assembly  51  sub-assembly with the specified clearance. Since the re-bars  51  and the interface elements  11  extend above the concrete surface, it is possible to have continuity in the concrete structure from bottom to top. The extensible load support means  6  are retracted back in the permanent roof structure  1  before the concrete is poured. The construction sub-assembly  44  is supported by the temporary load support means  35  that are also used as concrete forms to pour concrete. The temporary load supporting forms  35  are equipped with a top interface, herein a top support cap  35 ′, that is capable of supporting the construction sub-assembly  44  and provide the next attachment points for the base of the extensible load support means  6 . The extensible load support means  6  retract inside the temporary load supporting forms  35  and are reattached on the top portion of the temporary load supporting forms  35 .  FIGS. 16A and 16B  show a concept where the top permanent portion of the temporary load supporting form  35  becomes the interface element  11 . In such case, the interface element  11  is providing support for the construction sub-assembly  44  and sits on top of the temporary load supporting form  35 .  FIG. 16B  specifically shows the extensible load support means  6  retracted and reattached on top of interface element  11 , which projects above the uppermost floor together with the re-bars assembly. 
     Because of the light construction of the permanent roof structure  1 , the extensible load support means  6  do not require to be positioned exactly in-line with the load bearing columns of the foundation  48  or the building best support points, unlike other known methods. The extensible load support means  6  are located either in-line with some identified supporting element  37  of the foundation  48  or close to the foundation  48  supporting element  37  or any point capable of supporting the extensible load support means  6  and total load that the extensible load support means  6  are supporting. 
       FIG. 16C  shows a plan view of a typical arrangement when the extensible load support means  6  are aligned with the permanent supporting element  37  of the building. In the concept shown, the temporary load supporting forms  35  are also used to protect the lower portion of the extensible load support means  6 , to guide and to secure the mobile sub-assembly  44 . In movement, the sub-assembly  44  follows the temporary load supporting forms  35  that also protects the extensible load support means  6 . At rest, a locking mean, such as a lock pin (not shown), is used to secure the sub-assembly  44  to the temporary load supporting forms  35 . As an alternate solution, the extensible load support means of  FIG. 16D  shows a plan view of a typical permanent roof structure  5  connection with an adaptation  52  when the extensible load support means  6  are offset from the permanent supporting element  37  of the building. 
     Extension of the Electrical and Communication Systems 
     Additional connectors, junction boxes and panels are installed to allow connection of new occupational floors to the existing electrical system. New cables can run all the way to the main panel in some cases and shielded bars are extended when adding a floor as the occupational need to do so arises. The access for electrical connections is set up on the last floor  34 , ready for the next construction phase. A floor main disconnect is already installed on the last floor  34  and is closed once the electrical work has been completed in the construction zone  3  and the construction sub-assembly  44 . 
     Extension of Main Conduits for Plumbing, Fire Protection, Ventilation . . . 
     The main conduits for water, fire protection, ventilation and sanitary drains typically reduce in size from floor to floor as it goes up in the building. The main conduits of the first floor, for example, must be designed adequately for the future needs and be able to sustain the demand when the number of floors increases. The main conduits are extended using extra sections of conduits. The ends of the conduits are equipped with valves, quick connecting devices, sealing caps or removable covers. Valves are necessary to allow the connection of a new network on a pressurized conduit without disturbing the operation of the existing portion. It is possible, when required, to elaborate a double network of conduits, temporary or permanent, in order to avoid service interruption to the occupied floors  4  under the construction zone  3 . 
     Extension of the Occupants Elevator Shafts and Stroke 
     The occupants elevator drives and the mechanical room for elevators can be located in the basement, in the elevator shaft or above the elevators, on a frame similar to the frame  23  shown in  FIG. 25 , or in a displaceable enclosed mechanical room comprising a bottom frame similar to the frame  23  and a covering mean to enclose the mechanisms. With the displaceable drive concepts, the permanent roof structure  1  needs to plan for clearance to allow its vertical movement without interfering with the occupants elevator mechanical room or frame  23 . 
     When extending the building as the occupational need to do so arises, the sequence and method for extending the elevator shaft  38 , the guide rails, the cables, the relocation of the travel limit switches and all other components requiring to be extended follow the same principle than the one applicable for the permanent vertical transportation mean  24 . 
     When adding a floor to the building, the effective stroke of the occupants elevators needs to be adjusted by adapting the control system such as changing a register in the program of the programmable logic controller (not shown), by extending the guide rails (not shown), by relocating the travel limit switches (not shown). To extend cables, it is possible to secure the cage  24  to the building structure  38  with pins or bumpers (not shown). The extra cable required has to be already available on an accumulation drum that is normally locked, but is released during the operation of lifting the occupants elevator drive mechanism. While the drive mechanism, or mechanical room, of the elevators is lifted by the extensible load support means  6  of the permanent roof structure  1 , the accumulation drum releases the amount of cable required for the elevator cage additional stroke. From the beginning of the construction, the accumulation drum needs to store the cable required for the maximum stroke the elevator cage will ever do, otherwise the cable will need to be changed in the course of the construction. 
     For traction type drives, the extensible occupants elevator comprises a traction disk or pulley  59 , a synchronization drum  58  used only during extension, a cable holding means  57 , a cable accumulation means  56 , a governor device  60  with its specific governor accumulation means  61 , a passenger cabin  63  and a counterweight  62 . All the drive components can be mounted on a displaceable frame  23  such as shown in  FIG. 4B  or partially in an elevator pit such as shown in  FIG. 4C . After the guide rails, the shafts have been extended and the travel limit switches have been relocated, an example of extension procedure is to proceed with the following steps:
         1. Locate both the cabin  63  and the counterweight  62  at the same reference position,   2. then, the governor accumulation means  61  is unlocked but keeps the governor device  60  in tension,   3. the frame  23  is raised a predetermined distance by the extensible supporting means  6  in the permanent roof structure  1  or separate lifting device,   4. the governor accumulation means  61  is locked at its new extended stroke,   5. the cable holding means  57  and the cable accumulation means  56  are unlocked,   6. the synchronization drum  58  releases cable and lowers the cabin from the same pre-determined distance while the traction pulley  59  remains at rest,   7. the cable holding means  57  and the cable accumulation means  56  are locked,   8. the traction pulley drives the cabin  63  and the counterweight  62  at the same reference position,   9. the extension is complete but the elevator stroke has been increased by the pre-determined distance.       

     A similar procedure can be used for an elevator pit drive as shown in  FIG. 4C . Also, a similar procedure can be completed with the counterweight  62  moving instead of the cabin  63 , if the cable accumulation means  56  and the synchronization drum  58  are assembled on the counterweight side instead of the cabin side. Also, step  1  or  9  are not necessary as the verification of correct positioning can be accomplished in many different ways. The occupants elevator extension can be performed one or multiple stories at a time and one or multiple elevators at a time. Finally, the support frame  23  or the mechanical room can sit on top of the elevator shaft structure or be secured within the shaft. 
     Extension of Stairs 
     The stairs wells and the elevator shaft always extend higher than the last floor constructed  34 . Both are extended as floors are added. The stairs provide access to the last floor constructed  34  and the permanent vertical transportation mean  24  can access the last floor constructed  34  as well in order to start the construction of the next floor as occupational need to do so arises. 
     Location of the Building Systems Machinery 
     The description disclosed hereby assumes that the building heating, air conditioning, water treatment and other units are installed mostly at the lower and intermediate levels. If the units are installed on the permanent roof structure  1 , the lifting capacity of the extensible load support mean  6  and the driving means  9  are modified accordingly and further adaptation will be required to the conduits network to avoid service interruptions to the occupied floors. 
     Example of Construction Process Possible with the New Construction System 
     
         
         
           
             1. Construction of a foundation  48  having a top shape, or a first floor geometry, similar to the shape desired for the permanent roof structure  1  but not extending the shape of the permanent roof structure  1 . 
             2. Installation of the permanent roof structure  1  at its position A ( FIG. 18 ) on the foundation  48 , with a guiding device  12  anchored to the foundation  48 . The base of the extensible load support means  6  are fixed to the foundation  48  using an interface element  11 . 
             3. Installation of the permanent retractable wall enclosure  18  and fixation of its rigid platform  19  to the building or a wall enclosure as shown in  FIG. 11B  or  FIG. 11C . 
             4. Construction of the first sections of the building structure  38  for the elevator shaft and stairs wells. 
             5. Installation of vertical transportation means or elevator cabin  24  and construction of the first stairs. 
             6. Mechanical and electrical connection of the systems to provide services to the permanent roof structure  1  and make everything operational. 
             7. Inspection of the operation of all the systems and safety devices. 
             8. If occupational spaces are planned within the foundation  48  of the building, the occupational spaces construction can be completed totally or partially at this stage, for normal or temporary usage. 
             9. In order to create a first standard construction zone  3 , the permanent roof structure  1  is lifted at its position B ( FIG. 19 ) by the extensible load support means  6  to create a workspace under the permanent roof structure  1 . 
             10. The structural elements, components and materials are assembled in the construction zone  3  into a construction sub-assembly  44  that sits on the last floor constructed  34  or on adjustable bumpers (not shown). At this stage, the permanent roof structure  1  is lifted high enough by the extensible load support means to allow workers to walk on the construction sub-assembly  44  and to install a steel deck  49  when applicable. The construction sub-assembly  44  typically starts on the outer portion of the floor and progresses towards a permanent vertical transportation mean  24  to simplify material handing during the assembly. 
             11. Once all the work performed with the construction sub-assembly  44  sitting on the last floor constructed  34  is complete or on bumpers (not shown), the permanent roof structure  1  is lowered at its position C ( FIG. 20 ) to hook the construction sub-assembly  44  to the permanent roof structure  1 . A set of adjustable hoisting means  13  is used to hook the construction sub-assembly  44  to the permanent roof structure  1 . The adjustable hoisting means  13  allow the workers to adjust the height of the construction sub-assembly  44 , as it is desired, at any stage of the assembly work, using the extensible load support means  6  of the permanent roof structure  1 . This allows the workers to work at the best ergonomic, and most productive heights during the assembly work, for example when assembling horizontal conduits of plumbing, ventilation conduits, and electrical wires. 
             12. Once the assembly of horizontally oriented components and materials into the construction sub-assembly  44  is substantially completed, the permanent roof structure  1  and the hooked constructions sub-assembly  44  are lifted at a pre-determined height (position E,  FIG. 22 ) to allow the installation of the permanent building columns or temporary load supporting forms  35  that will support the construction sub-assembly  44 . 
             13. With the columns or temporary load supporting forms  35  in place, the extensible load support means of the permanent roof structure  1  lowers the construction sub-assembly  44  to its final design position F ( FIG. 23 ) where it is attached to the temporary load supporting forms  35 . 
             14. The permanent roof structure  1  is now supported by the adjustable hoisting means  13  on top of the construction sub-assembly  44  that rests on the last floor constructed  34  or on mechanical bumpers (not shown). This allows the extensible load support means  6  to be lifted or retracted back into their storage location into the permanent roof structure  1  and to reattach the bases of the extensible load support means  6  to a newly installed interface elements  11 , one floor higher than the bases were previously attached, as shown in  FIG. 24 . 
             15. Adjustable hoisting means  13  are folded back into the permanent roof structure  1  and the permanent roof structure  1  can be further lifted to proceed to concrete work, if applicable. 
             16. Pouring of the concrete into the steel deck  49 , on top of the construction sub-assembly  44 . The interface elements  11  have sufficient openings to allow concrete to flow through and fill the temporary load supporting forms  35 . 
             17. Removal of the temporary load supporting forms  35  to be reused for the next floor construction. 
             18. Completion of the vertical conduits installation, construction of interior divisions and connection of the horizontally oriented components of the construction sub-assembly  44  to the vertically oriented conduits. The floor construction can be completed until it is ready for occupation. 
             19. Pre-fabricated structural elements are added to structure  38  to extend the structure  38  by one floor. 
             20. While the permanent roof structure  1  is lifted to the position H ( FIG. 25 ) by the extensible load support means  6 , a set of catcher  33 , part of the structural element  5  of the permanent roof structure  1 , picks up the frame  23  to raise it at a pre-determined height. This operation allows the installation of a new set of bumpers  32 , one floor higher than the previously installed bumpers. 
             21. The frame  23  is lowered on its new set of bumpers  32  and attached to the structure  38 . The programmable logic controller is reprogrammed, guide rails are extended, and travel limit switches are relocated one floor higher and all other devices of the permanent vertical transportation mean  24  is adjusted to allow for the new stroke. Similar operations are completed in a more complete procedure for the occupants elevators as described previously. 
             22. The permanent roof structure  1  is lowered to its position I ( FIG. 26 ) and is attached to the building using interface elements  11 . 
             23. Inspection of the construction of the new floor and start up procedure for all the systems is effected. The newly constructed floor can now be occupied. 
           
         
       
    
     Each subsequent floor construction typically starts at step  9  of the above construction process. 
     The construction process can also be adapted to specific project or building requirements. For example, a divided permanent roof structure  1  as shown in  FIG. 17C  allows the construction process to adapt to multiple floor size projects. Therefore, when the geometry of surface changes at a given storey or level, a section  53  or  54  of the permanent roof structure  1  can remain on the previously constructed larger floor while the remaining sections continues on. At least on section  55 , such as shown in  FIG. 17C  will continue to the final height of the building, unless an additional architectural or structural element (not shown) is added on top of section  55  as a past phase of construction. It is also contemplated that the construction system can be used as an extension to an existing building. The system also contemplates architectural designs where part or sections of the building is constructed by known conventional methods where specific roof structures are required. 
     The Table below lists the differences between the features of the disclosed construction system and method of the present invention versus the existing or traditional method of construction. 
     
       
         
               
               
               
             
           
               
                   
               
               
                   
                 EXISTING  
                   
               
               
                 TYPE 
                 METHODS 
                 NEW METHOD &amp; SYSTEM 
               
               
                   
               
             
             
               
                 Material 
                 Tower cranes 
                 Enclosed vertical transportation means 
               
               
                   
                 Exterior freight  
                 Permenent roof structure equipped 
               
               
                   
                 elevator 
                 with extensible load support means 
               
               
                   
                   
                 for vertical movement in the 
               
               
                   
                   
                 construction zone. 
               
               
                   
                 Boom lifts 
                 Dock station with dock lift and 
               
               
                   
                   
                 equipment peripheric monorail 
               
               
                   
                 Fork lifts 
                 Fork lifts and other standard  
               
               
                   
                   
                 handling equipment 
               
               
                 Ergonomics/ 
                 Scissors, Ladders, 
                 Permanent roof structure locating 
               
               
                 Security 
                 stepladders, stools 
                 the sub-assembly anywhere it is 
               
               
                   
                   
                 required for best ergonomic work 
               
               
                   
                   
                 position  
               
               
                   
                 Scaffoldings 
                 Wheeled trolleys 
               
               
                   
                 Temporary heating 
                 Heated, lighted and controlled work 
               
               
                   
                   
                 environment 
               
               
                   
                 Temporary 
                 Permanent protection from inclement 
               
               
                   
                 protection against 
                 weather conditions 
               
               
                   
                 inclement 
                   
               
               
                   
                 weather conditions 
                   
               
               
                   
                 Temporary guard 
                 Wall enclosure 
               
               
                   
                 rails 
                   
               
               
                 Occupants 
                   
                 Interior permanent extensible elevator 
               
               
                 elevator 
                   
                   
               
               
                 Access and 
                 Exterior unloading 
                 Indoor unloading dock 
               
               
                 control 
                 Exterior offices 
                 Interior offices 
               
               
                   
                 Surrounding 
                 Controlled access, lockable site 
               
               
                   
                 gates and panels 
                   
               
               
                 Financing 
                 Critical initial 
                 Lease and funds entry as soon as the 
               
               
                   
                 occupational ratio 
                 first floors are completed 
               
               
                   
                 Financing on the 
                 Construction, and financing 
               
               
                   
                 total investment 
                 according to, as occupational need 
               
               
                   
                   
                 to do so arises 
               
               
                 Occupation 
                 Occupation at the 
                 Occupation of completed floors 
               
               
                   
                 end of the total 
                 simultaneously to construction is 
               
               
                   
                 construction 
                 possible 
               
               
                   
                 project 
                 Extensibility of the building systems 
               
               
                   
                   
                 to maintain services for occupants 
               
               
                   
                   
                 Passenger elevators dedicated to  
               
               
                   
                   
                 occupants 
               
               
                   
                   
                 Permanent vertical transportation 
               
               
                   
                   
                 mean for vertical material 
               
               
                   
                   
                 transportation during construction 
               
               
                   
                   
                 and for post construction use  
               
               
                   
                   
                 (renovation, relocation of  
               
               
                   
                   
                 occupants . . . ) 
               
               
                   
               
             
          
         
       
     
     It is within the ambit of the present invention to cover any obvious modifications of the preferred embodiment descried herein provided such modifications fall within the scope of he appended claims.