Method for modernizing a building and structure with an elevator system constructed in a building

In a method for modernizing a building, a former stairwell of the building is converted such that an elevator shaft of an elevator system to be constructed can be provided in the former stairwell. The elevator shaft is provided in the former stairwell of the building such that stepless access is facilitated to specific floors of the building from an elevator car of the elevator system, which car can be provided in the elevator shaft. A new staircase is constructed outside the former stairwell. In addition, a former staircase is removed from the former stairwell. Furthermore, access bridges are disposed next to the elevator shaft in the former stairwell, thereby enabling flush access from the new staircase to the specific floors.

FIELD

The invention relates to a method for modernizing a building, conversion taking place in the region of a stairwell of the building, which conversion relates to regions outside the stairwell, in particular outside the building, and enables installation of an elevator system into the stairwell. The invention further relates to a structure with an elevator system constructed in a building.

BACKGROUND

A preferred starting point is an existing building, such as an apartment building, an office building, an administration building or the like, in which access to specific floors is possible only via a stairwell. This also includes situations in which, for example, a modern or already modernized part of a building already comprises at least one elevator system, and an older or non-modernized part of the building is to be equipped with an elevator system. When the building having at least one or at least one additional elevator system is upgraded, accessibility via a staircase in close proximity to the constructed elevator should still be ensured at the same time. In this case, the individual floors of the building should be developed such that they can be reached in a flush and preferably barrier-free manner via the elevator system to be constructed.

One particular application relates to a building of this kind, in which the individual floors can so far be reached only via the existing staircase. This is because conversion, in particular when the staircase is demolished in part, can lead to restrictions to the accessibility of the building, which considerably restricts the scope of application if the usability of the building cannot be ensured during conversion.

DE 10 2011 115 217 A1 discloses a method for converting a double-run stairwell without an elevator shaft into a staircase having a single-run staircase, bridge and elevator shaft in front thereof. In this method, an extension is constructed outside the previous building, which extension comprises an elevator shaft and an expansion of the previous stairwell, which expansion is open towards the previous stairwell. Due to this expansion, landings can be implemented, via which an elevator arranged in the elevator shaft can be accessed. Furthermore, a flight of stairs can be extended into the expansion. As a result, the other flight of stairs in each case can be removed and bridges for the individual levels can be inserted at the points thereof.

The method known from DE 10 2011 115 217 A1 has the disadvantage that implementation may not be possible in each specific case, which therefore restricts the scope of application. A problem in this regard is in particular the large enclosed construction volume of the extension, which is required for expanding the stairwell and for the elevator shaft outside the previous building. This can be problematic with regard to the practically available space and for aesthetic reasons. However, legal regulations should also be observed, which preclude a solution of this kind in principle or at least in practice. For example, regulations with regard to distance spaces to be observed can have the result that the construction project cannot be approved for legal reasons. Alternatively, this can be achieved only with an elevator shaft that is smaller than desired. In addition, facilitations or exemptions with regard to building regulations may not be possible. For example, an exemption of this kind, which relates to facilitations with regard to the required distance spaces, for example, may relate only to retrospectively constructed stairwells, but not to extensive constructions that include an elevator shaft. There is another disadvantage with regard to connecting or directly spatially expanding the stairwell in the additional extension. This may make it necessary to completely integrate the extension into the outer insulation of the building.

DE 10 2014 114 904 A1 discloses arranging an elevator in the stairwell of an existing building. The starting point of the conversion for this known structure is a building that includes a stairwell extending from a basement over several floors and having intermediate landings arranged halfway up each floor. Before conversion, there is the problem that one flight of stairs has to be climbed from each intermediate landing in order to reach a floor. An elevator arranged outside the building, which elevator stops at the intermediate landings, can therefore not allow barrier-free access to the individual floors. It is therefore proposed to attach an extension that expands the stairwell beyond the previous outer wall, the previous intermediate landings, which are arranged inside the original stairwell, becoming components of the new staircase. The removal of a flight of stairs made possible thereby therefore creates space for an elevator arranged inside the previous stairwell.

The structure known from DE 10 2014 114 904 A1 has the disadvantage that opening the previous stairwell to the outside during conversion may make it necessary to completely integrate the extension into the outer insulation. Furthermore, the horizontal cross section provided for constructing the elevator shaft is restricted by the remaining intermediate landings and the available flights of stairs. Therefore, despite extensive conversion measures, only a small elevator can be implemented if necessary.

SUMMARY

A problem addressed by the invention is to specify an improved method for modernizing a building and an improved structure with an elevator system constructed in a building. In particular, a specific problem can be considered that of implementing a comparatively large elevator system, in particular a comparatively large horizontal cross section of the elevator shaft, with regard to the necessary conversion work, thus leading to a greater scope of application, as requirements with regard to construction and building regulations can be met more easily. Furthermore, a specific problem can be considered to be that of enabling installation of the elevator system into the existing building and the conversion of the building required for this purpose such that the building remains at least largely usable and in particular accessible during conversion. Another specific problem can be considered that of restricting required conversion and expansion work to the building to relatively simple construction and demolition work, in particular changes to an outer wall or outer façade being minimized.

In the following, solutions for a corresponding method and for a corresponding structure with an elevator system constructed in a building are specified, which solutions solve at least one of the problems mentioned. Furthermore, advantageous developments and embodiments are specified.

A proposed solution consists in a method for modernizing a building, a former stairwell of the building being converted such that an elevator shaft of an elevator system to be constructed can be provided in the former stairwell, and the elevator shaft being provided in the former stairwell of the building such that stepless access is facilitated to specific floors of the building from an elevator car of the elevator system, which car can be provided in the elevator shaft, and a new staircase being constructed outside the former stairwell, the former staircase being removed from the former stairwell at least in a region of the former stairwell extending over the specific floors and access bridges being disposed next to the elevator shaft in the former stairwell, thereby enabling substantially flush access from the new staircase to the specific floors. The access bridges are substantially step-free. This means that the access bridges are designed as horizontal longitudinal supports, this substantially meaning that individual landings or thresholds can be present in transition regions and door regions if need be. The connection from the new staircase to each floor is therefore substantially flush. The access bridges are preferably substantially horizontal.

A further solution consists in a structure with an elevator system constructed in a building, an elevator shaft of the elevator system being arranged in a converted former stairwell of the building and the elevator shaft being arranged in the former stairwell of the building such that stepless access is facilitated to specific floors of the building from an elevator car of the elevator system, which car is provided in the elevator shaft, a new staircase being provided which is constructed outside the former stairwell, access bridges being provided which are disposed next to the elevator shaft in the former stairwell, and access, preferably flush access, from the new staircase to the specific floors via the access bridges being facilitated.

When the former staircase is removed from the former stairwell, it is essential that the functional purpose of the former staircase, i.e. the ability to reach the individual determined floors via said staircase, no longer exists after removal. The former staircase can be removed, depending on the design of the former staircase, by means of demolition, for example. However, it is conceivable in this case that parts of the former staircase remain intact, in order to serve as support bearings for the access bridges or as fastening points for the elevator system to be constructed, for example.

Advantageously, the new staircase is outside the former stairwell. It is therefore possible that the former stairwell and the new stairwell in which the new staircase is constructed are spatially separated. In particular, the thermal insulation can be maintained at this location in an optionally renewed form. This may lead to cost-optimized implementation of an extension in which the new stairwell is enclosed. In each application, this makes it possible to design an outer and/or emergency exit staircase.

It is therefore advantageous that the new staircase is constructed in a new stairwell which is separated from the former stairwell by a wall of the building, and that preferably passages are formed in the wall which can preferably be closed by doors and facilitate access from the new staircase to the specific floors or to the access bridges. The measure, which is to be regarded as an option, of closing passages in the wall by doors makes it possible to implement thermal insulation, as required on the outer side of the building, in particular with low effort. In this case, it is advantageous that the wall of the building is at the point of an outer wall or a former outer wall of the building. The doors may also be designed as fire doors, so that in the event of a fire, the new stairwell can be used as an evacuation staircase. There may therefore be no need for storage spaces, which might otherwise be required for placing evacuation ladders or the like.

If the access bridges or the specific floors can be accessed from the new staircase through closable passages in the wall, lower access to the new stairwell can be open. Alternatively, access from the new staircase to the access bridges can be open, of course, and only the lower access can be closed by a main door or, if access doors to the individual apartments of a floor are designed as external doors, any closable doors in the region of the new stairwell can be dispensed with.

In an advantageous embodiment, the new staircase can therefore be constructed in a new stairwell that is designed as an attached cold stairwell. This results in the advantage that the new stairwell additionally attached to a certain extent accommodates the new staircase completely, but also that the volume enclosed by the extension can be restricted at the same time to the minimum space required in each application. As a result, a special arrangement with regard to building regulations is possible for a retrospectively attached staircase space, which makes only reduced distance spaces necessary. In this case, reinforced concrete parts and/or prefabricated parts equipped with sheet glass and/or other prefabricated parts can be used, so that the staircase can be protected against the weather with little effort. The construction and dimensions of the new staircase can be adapted to desired properties in this case. For example, the requirement that a stretcher can be transported via the staircase in the event of a fire is taken into consideration. Furthermore, it may be necessary or desired that elements, in particular access bridges, can be brought to their position in the former stairwell via the new staircase for conversion. “Via the new staircase” does not mean that the access bridges have to be carried up through the stairwell. The stair construction of the new staircase may, for example, have support points that enable a lifting device for lifting the access bridges to be fastened, so that the access bridge can be lifted along the staircase façade of the new staircase and brought into the building at the height of the corresponding floor. The access bridges may also be lifted by means of a movable hoisting crane, of course.

The new stairwell, which is aligned with the floor locations of the specific floors, can be lifted advantageously at the beginning of the conversion process. In this case, the new stairwell can advantageously comprise both the stair structure for the staircase and a wall end to the building. In this case, the wall end may comprise thermal insulation, a supporting structure for the access bridges to be installed and the like.

Preferably, starting from the top, the flights of stairs and optionally parts of the old building outer wall can be removed floor by floor and an access bridge can be inserted on the relevant floor. The access bridge then leads in a flush, substantially horizontal manner from the new stairwell to the relevant floor.

It is advantageous that the access bridges are designed so as to have a minimum permissible access width at least along an access portion, passing the elevator shaft, between the staircase and a relevant floor landing. Specifically, the access bridges may have a minimum access dimension of from 0.9 m to 1.0 m, for example. The minimum access dimension is preferably specified such that the access bridge can be used as an escape route. Designing the access bridge to the minimum access dimension makes it possible to produce the largest possible open space for the future elevator system, in order to be able to install the largest possible elevator car. After an access bridge has been installed, the corresponding floor can be accessed again immediately. Depending on the necessary conversion measures, in particular the time required for demolishing a flight of stairs, it is possible that access to an individual affected floor is obstructed only for a few hours. The building is therefore substantially continuously accessible during the conversion work, with the exception of temporary restrictions that may relate to only one floor in each case depending on how conversion is carried out. In this case, when the relevant flight of stairs is being removed and when the corresponding access bridge is installed, a temporary protective roof can be assembled in order to protect lower staircases and/or to facilitate access via a lower staircase of this kind. Occasionally, lower flights of stairs can also be temporarily shut for reasons of safety.

It is also advantageous that the access bridges are designed so as to have an access width at least along an access portion, passing the elevator shaft, between the staircase and a relevant floor landing, which access width is smaller than a width of a former flight of stairs of the former staircase. Space that is provided for the elevator shaft can therefore be correspondingly larger. In particular, the elevator shaft can then extend horizontally over a cross section that projects beyond a horizontal cross section of an individual flight of stairs.

It is advantageous that the former staircase is removed from the former stairwell at least in the region of the former stairwell extending over the specific floors and the access bridges are arranged in the former stairwell. In particular, the new staircase can therefore be constructed at the beginning or at least after required openings have been made in the wall, in particular the outer wall. Access is therefore possible via the new staircase both to the individual floors, which are already connected via access bridges, and in order to carry out work. For example, the access bridges can be transported via the new staircase, if the new staircase has been constructed in a correspondingly suitable manner.

It is also advantageous that the access bridges are arranged successively in the former stairwell from the uppermost floor of the specific floors to the lowermost floor of the specific floors. This means that, for example, some of the specific floors can still be accessible from a ground floor, while other floors are gradually connected, from top to bottom, to the new staircase via the access bridges. Aside from temporary interruptions, which can last for a few hours, for example, and may each affect only one floor, all the floors of the building are still accessible even during conversion work. Conversion can therefore be ensured during operation or whilst the building is inhabited. It is therefore also advantageous in this case that an access bridge for one of the specific floors is arranged in the former stairwell in each case in a stepwise manner and the former staircase between this specific floor and the specific floor underneath is removed. In order to remove the staircase portion, a protective roof may be temporarily inserted. When the stair portion is removed, two flights of stairs and an intermediate platform arranged therebetween, which is located halfway up the floor, for example, can be removed, for example.

Alternatively, the access bridges can of course be arranged or integrated in the former stairwell successively in the reverse sequence from the lowermost floor of the specific floors to the uppermost floor of the specific floors, particularly if the building is not occupied during the conversion phase. Occasionally, all the former staircases can also be removed in a first step, such that the stairwell is empty and the access bridges can, together with the wall for the elevator shaft, be inserted and installed into the stairwell.

It is advantageous that a wall for the elevator shaft is constructed in the former stairwell and that the former staircase is removed from the former stairwell at least in the region of the former stairwell extending over the specific floors and the access bridges are arranged in the former stairwell before the wall for the elevator shaft is constructed in the former stairwell. Specifically, after the new staircase is constructed and all the planned access bridges are introduced, conversion can first take place such that all the floors are linked via the new staircase, if required. In this case, a ground floor may in particular be accessible via the entrance to the building. As a result, the major disturbances caused by the conversion work, which arise due to the dirt produced and the noise pollution during demolition, are restricted to a short period, in particular a few days. Subsequently, the work required for constructing the elevator system can be carried out at least substantially. This makes it easier to plan and coordinate the individual trades.

The wall for the elevator shaft that is constructed in the former stairwell can advantageously be composed of wall elements. In this case, the wall elements may be designed such that they can be inserted in each case between two access bridges arranged one on top of the other. In this case, the access bridges can be prepared accordingly in order to make it easier to install the wall elements. Specifically, it is advantageous in this case that the wall for the elevator shaft from the lowermost floor of the specific floors to the uppermost floor of the specific floors is composed of wall elements of this kind. The individual wall elements can therefore be gradually supported on one another during installation. Furthermore, a connection to each access bridge can be established. The wall bridges can in particular have an angular profile that is U-shaped in the horizontal cross section and can be open to a wall of the former stairwell. The wall elements are preferably also fastened to this wall. The wall elements can be made in part from transparent material, such as glass. This improves the light flooding into the floor space.

In one embodiment, the wall elements for the wall of the elevator shaft can also be assembled starting from the top. In this case, a free lower space in the stairwell, which is produced by the space next to the access bridges, can be used for transporting the wall elements. Selecting the suitable assembly sequence depends on the design of the wall elements, for example.

It is advantageous that components for the elevator shaft are already attached to the access bridges during arrangement in the former stairwell. Components of this kind may be, for example, parts of the future wall of the elevator shaft, door attachment parts or fastening structures for fastening guide rails. This makes it possible, for example, that essential preliminary work can already be carried out before the access bridges are delivered to the building site. This decreases the time required for installation into the building. In addition, the danger of falling tools and components and the danger of a technician or builder falling can be reduced, as parts are already fastened to the access bridges.

Furthermore, it is advantageous that a handrail is fastened to the access bridges after arrangement in the former stairwell at the latest and at least until a wall is constructed for the elevator shaft, which handrail prevents falling into the elevator shaft. This handrail can be removed completely or in part after the wall for the elevator shaft has been constructed. Depending on application, a handrail of this kind can optionally be pre-assembled on the access bridges completely or in part. In one embodiment, the handrail may also be a component of the wall for the elevator shaft. The handrail may be a fixed balustrade, for example, on which glass walls can be placed during subsequent completion of the wall.

The access bridges can therefore already have attachment parts of the future elevator or for the future wall or at least elements for a handrail.

It is also advantageous that the new staircase is constructed such that the access bridges can be brought to the specific floors via the new staircase at least in order to construct the elevator system. In this case, devices which make lifting the access bridges easier can be installed at least temporarily in the new stairwell. Furthermore, the new stairwell can be at least partially opened for this purpose, so that it is possible to lift the access bridges next to the new staircase, for example. In particular, a front of the new stairwell further away from the former stairwell can be closed only when the access bridges are inserted into the former stairwell.

In particular, it is advantageous in this case that the access bridges are designed as longitudinally adjustable access bridges. For example, the access bridges can be longitudinally adjustable in accordance with a telescopic design. This facilitates precise length adjustment at the installation location. Transport of the access bridges to the installation location is also made easier as a result.

It is also advantageous that a counterweight space, which is reserved for the travel of the counterweight in the elevator shaft, is implemented on a side of the elevator car nearer the new staircase or on a side of the elevator car further away from the new staircase. The horizontal cross section provided for the elevator car can therefore be optimized.

In an alternative arrangement, the counterweight space of the elevator system is installed in the new stairwell. The counterweight space can be arranged on a side of the new stairwell nearer the elevator car. The counterweight space can therefore be constructed during installation of the new stairwell. Essentially, a passage through the zones of the former outer wall of the building is provided only in the uppermost region of the stairwell, through which passage a suspension means, which connects the counterweight to the elevator car, can be guided. A drive of the elevator system or deflection rollers can also be arranged in this uppermost region if necessary. Inspection openings can be arranged in the new stairwell, which openings make it possible to service the counterweight. This alternative makes it possible to pre-assemble the counterweight when the new stairwell is attached to the building. This can decrease the assembly time in the building itself.

DETAILED DESCRIPTION

FIGS. 1A and 1Bare flow diagrams for explaining an embodiment of the invention. The flow diagram is shown in two parts here, there being a connection at the connector A-B. The flow diagram begins with a state Z1, in which a building1is in an initial state. The building1comprises a former stairwell3having a former staircase4. The former stairwell3and the former staircase4are referred to as “former” in this case in order to ensure that referencing is consistent throughout. In the context of planned conversion work to the building1, the former staircase4is removed at least in substantial parts, so that it no longer functions as a staircase.

The former staircase4comprises flights of stairs5,6,7(FIG. 2D). The view of the state Z1shows the flights of stairs5,6. The flights of stairs5,6are interconnected via an intermediate landing8of the former staircase. Furthermore, a floor landing9is provided which is observed as independent of the former staircase4here. This means that the floor landing9is at least substantially maintained in the context of the conversion works, even if the floor landing9has the function of a stair landing of the former staircase4.

Rooms12,13inside the building1are accessible from the floor landing9via doors10,11. For access to the rooms12,13, access to the floor landing9is essential.

The building1comprises a wall15, which is an outer wall15in this embodiment. In this embodiment, a window16is inserted into the outer wall15, so that daylight can enter the former stairwell3.

In the state Z2, a new staircase17is constructed outside the former stairwell3. In this case, the new staircase17is separated from the former stairwell3by the wall15. In this case, the new staircase17can be protected from weather influences by side walls18,19,20, of which the side walls18,19connect to the wall15. The side walls18to20enclose a new stairwell21for the new staircase17. It is optionally also possible, however, that one or more of the side walls18to20are attached only at a later point in time. In particular, the side wall20may initially remain open in order to bring necessary building materials or components to the individual floors via the new staircase17.

In the state Z3, the wall15has been converted such that the window16is dispensed with and is correspondingly closed in part and that a door22is integrated into the wall15at a passage14introduced into the wall15, via which door access is facilitated into the former stairwell3from the new staircase17. Furthermore, a horizontal access bridge24is arranged between the new staircase17and the floor landing9. When the door22is open, substantially flush access from the new staircase17to the floor landing9via the new staircase17, the passage14and the access bridge24is possible. The two flights of stairs5,6can be demolished at substantially the same time. The access bridge24is connected at one end to the substantially existing floor landing9and the other end can be connected to a staircase landing23of the new staircase17or it can alternatively be supported on existing side walls of the former stairwell3, for example.

The measure described with reference to state Z3is correspondingly repeated for each floor, until the former staircase4is completely demolished. This can lead to an open space25in the state Z4, for example, which open space can be used inter alia for the insertion of an elevator system2.

In the state Z5, the open space25is used in part by the elevator system2, an elevator car27of the elevator system2being arranged in an elevator shaft26of the elevator system2. Furthermore, a counterweight space29is provided on the side28nearer the new staircase17, in which counterweight space a counterweight30of the elevator system2is arranged. Furthermore, the access bridge24is extended to a landing31.

In a modified embodiment, the counterweight space29may also be arranged on the side32of the elevator car27further away from the new stairwell21.

As shown in the state Z5, the access bridge24comprises an access portion35passing the elevator shaft26. The access portion35is designed having a minimum permissible access width36in this case. Additionally or alternatively, the access portion35may also have an access width36which is smaller than a width37of a former flight of stairs6of the former staircase4, as shown in state Z3. As a result, in particular a width38of the elevator shaft26is optimally large.

This ensures stepless and preferably barrier-free access to the spaces12,13from the elevator car27via the access bridge24and the floor landing9.

In the embodiment shown inFIGS. 1A and 1B, an elevator car door may be provided on the side32nearer the floor landing9, or on a side39nearer the access bridge24. When there is sufficient space, it may be advantageous to arrange the elevator car door on the side32, as this is nearer the doors10,11to the rooms12,13. However, arranging on the side39usually has the advantage that a larger door opening is possible due to a correspondingly large elevator car door. In a specific arrangement, the door leaves of an elevator car door can also be arranged over a corner of the elevator car27, which corner preferably relates to the sides32,39, thereby allowing very wide access to the elevator car27.

In a modified embodiment, in which the counterweight30is arranged for example on the side32of the elevator car27, it is possible to exit via the side28to the platform31. This facilitates access to the elevator car27on the ground floor.

The structure and arrangement of the new stairwell21can take fire safety requirements into consideration by maintaining appropriate distances to adjacent windows40,41of the building1. In addition, modernizing elements, such as a riser for extinguishing water, communication lines and the like, can also be arranged in the new stairwell21and/or in the former stairwell3.

Auxiliary means related to fire safety can be integrated in the new stairwell21and the access bridge24. The access bridge24can therefore be equipped with sprinkler systems or with sprinkler heads33(FIG. 2E), which are supplied by lines for extinguishing water integrated in the new stairwell21. At the same time, the access bridges24may also be provided with water drain channels34(FIG. 2F) which divert extinguishing water outward into the new stairwell21if necessary. In principle, the access bridge24can therefore be designed as a protective zone.

A space-saving design of the elevator system2with simultaneously large car dimensions of the elevator car27and of the elevator shaft26can be achieved. Simultaneously, further safety requirements for the building, such as requirements with regard to fire safety, can be easily met.

FIG. 2A to 2Fare partial, schematic, three-dimensional views of the building1in different states according to a possible conversion with the construction of an elevator system2corresponding to a possible embodiment of the invention. It should be noted here that modifications are shown with regard to the embodiment shown inFIGS. 1A and 1B.

The conversion generally relates to specific floors42to46, which are usually specified by planning the conversion project. Correspondingly, a region61of the former stairwell3extending over the specific floors42to46is produced, in which region the former staircase4is removed from the former stairwell3, according to planning. In this case, all the floors42to46shown are specified, for example, and the region61relates to the entire former staircase4.

FIG. 2Ashows the building1as an existing building1. In this case, an entrance door50is provided via which the former stairwell3is accessible. In the context of conversion, the entrance door50can be converted without barriers or a barrier-free entrance door50of this kind can be implemented at another location. In this embodiment, the former stairwell3is closed at the top by a roof slope51.

FIG. 2Bshows a first conversion measure. In this case, a new stairwell21is produced in front of the outer wall15of the building1. The new stairwell21is protected from weather influences by side walls18,19,20and a new roof element52. Due to the open view, the side wall19is not shown; however, said side wall is implemented opposite the side18in accordance with the view shown inFIGS. 1A and 1B. Glass elements can advantageously be integrated in the side walls18to20, in order to allow daylight to enter the new stairwell21. Furthermore, a design consisting of a correspondingly fire-resistant material may be possible in some cases, in order to provide fire protection. The roof element52functions simultaneously as an upper end of the former stairwell3after the building1has been converted. In this case, components53,54, in particular fastening elements53,54, which are used to construct the elevator system2can be fastened to the roof element52, which may be provided as a prefabricated part.

The new staircase17is constructed in the new stairwell21. Furthermore, conversion is carried out on the wall15, windows16being replaced with a door22and a window56by combination elements55in this embodiment. In this embodiment, this is achieved in that an additional wall57is constructed in front of the previous outer wall15. The outer wall15can then be completely or partially demolished in the region of the former stairwell3. However, other conversion measures are also conceivable.

In the context of conversion, the roof slope51is also removed at least in part.

FIG. 2Cshows a state of the building1during conversion, the roof pitch51already being demolished and the access bridge24being inserted into the former stairwell3. A handrail60is also installed on the access bridge24, so that passengers cannot fall into the existing elevator shaft26. In this state, access is possible to all the floors42to46of the building1. This access is possible specifically either via the former staircase4or via the new staircase17and the access bridge24with regard to the level on the floor landing9. This means that only the level of the building1on the floor landing9is subject to temporary access restrictions due to the conversion work.

Subsequently, the flights of stairs5,6and the intermediate landing8of the former staircase4are demolished.

FIG. 2Dshows the building1, a further access bridge24A already being inserted with regard to a lower floor. Access to a floor landing9A is possible from the new staircase17via the access bridge24A.

Correspondingly, the further flights of stairs, in particular the flight of stairs7, of the former staircase4are then demolished from the top to the bottom in a stepwise manner and access bridges24B,24C relevant thereto are introduced into the former stairwell3.

FIG. 2Eshows the building1after the former staircase4has been demolished floor by floor. The region61over which the former staircase4is demolished extends over the entire former staircase4. However, the region61can extend only over part of the former staircase4. For example, the former staircase4can also lead to a basement, the portion of the former staircase4relevant thereto being maintained. The basement is a floor which is not affected and therefore does not belong to the specific floors, i.e. the floors42to46here.

Furthermore, wall elements62can be arranged in the former stairwell3preferably from bottom to top and in particular can be connected to the access bridges24,24A to24C.

FIG. 2Fshows the converted building1having the schematically shown constructed elevator system2. In this case, the wall elements62form a wall63. The elevator car27and the counterweight30are therefore suspended from at least one suspension means65inside the elevator shaft26, which is enclosed by the wall63and a building wall64(seeFIG. 1B). A schematically shown drive machine unit66having a drive sheave can be fastened to the components53,54, around which drive sheave the at least one suspension means65is guided.

Furthermore, guide rails for the counterweight30and the elevator car27can be arranged in the elevator shaft26.

Components, in particular correspondingly dimensioned parts of the wall elements62, door attachments or fastening structures for fastening guide rails, can already be attached to the access bridges24,24A to24C when the access bridges24,24A to24C are arranged in the former stairwell3. The handrail60can therefore be designed as part of the wall element62of the elevator shaft26, for example, or a door threshold of a shaft door can be attached to the access bridge.

The invention is not limited to the embodiment, possible design and modifications described.