A BUILDING AND METHOD OF PRODUCING A BUILDING

Abstract: A method of producing a building of the kind comprising a primary chassis incorporating main roof beams (25, 26, 27, 28, 29, 31) supported on columns (12, 13, 14, 15, 16, 17, 18, 19, 22) and a main horizontal roof structure comprising said main roof beams and secondary roof elements (32), the method comprising the steps of: preselecting a standard design of secondary roof element having pre-selected standard horizontal dimensions such that a main roof structure of main beams and standard elements can be built with horizontal dimensions representing integral multiples of the standard horizontal dimensions; selecting main roof structure dimensions as a multiple of the standard element dimensions to fit within the required building periphery with a gap between at least part of the main roof structure and said periphery; erecting columns of a primary chassis to support a main roof structure at positions around the periphery of the required building; constructing the main roof structure from main beams and standard elements with main beams around the periphery of the main roof structure and with outward extensions from the main beams across the gap to the columns whereby the main roof structure is supported on the columns. The invention also extends to a building suitable for production by this method.

Description: A BUILDING AND METHOD OF PRODUCING A BUILDING The invention relates to buildings and methods of producing buildings. In the establishment of commercial and industrial buildings, speed of construction has significant economic advantages. A building project has to take place in several stages, starting with planning and site preparation and ending with fitting out. Many of these stages have to be carried out consecutively rather than concurrently. Any changes in procedure enabling normally consecutive operations to be carried out concurrently can lead to substantial savings of time. Time savings of this kind are particularly beneficial with large retail stores because opening a store early reduces the period of investment without return in the site and building works. One way of saving time in the design of a building is to standardise a particular form of structure which can be designed in advance of requirements for a particular building and which can be adapted simply to the requirements of a particular building when known. It is also advantageous to provide a basic building structure to a standardised design which can accommodate a wide range of variations in detail without requiring any variation in the basic structure. With such an arrangement, it is even possible to start building the main structure before all detailed requirements for the building have been specified or agreed, with confidence that the main structure can accommodate any reasonable design details established at a later date. The invention is concerned with a building and a method of producing a building which contribute towards achieving the above mentioned objectives. According to one aspect of the invention there is provided a building having a roof and exterior walls, a primary chassis of the building incorporating main roof beams supported on columns, a main roof structure extending over most but not all of the building as defined by its exterior walls and comprising main beams extending along the outer periphery of the main roof structure and secondary roof elements supported by the main beams, the columns being positioned at the exterior walls of the building, extensions of main beams beyond the periphery of the main roof structure connecting the main beams to the columns whereby the columns support the main roof structure, outer parts of the roof beyond the main roof structure being supported on main beams and on upright supports located along the line of the exterior walls of the building. By employing a primary chassis of smaller dimensions than the complete building, a standard, pre-designed roof structure may be selected. Details of the periphery of the building which affect its appearance and access can be chosen with a wide degree of flexibility after the finalisation of the design of the primary chassis and even after construction has commenced. A second aspect of the invention comprises a method of producing a building of the kind comprising a primary chassis incorporating main roof beams supported on columns and a main horizontal roof structure comprising said main roof beams and secondary elements, the method comprising the steps of: a pre-selecting a standard design of secondary roof element having pre-selected standard horizontal dimensions such that a main roof structure of main beams and standard elements can be built with horizontal dimensions representing integral multiples of the standard horizontal dimensions, b selecting main roof structure dimensions as a multiple of the standard element dimensions to fit within the required building periphery with a gap between at least part of the main roof structure and said periphery, c erecting columns of a primary chassis to support a main roof structure at positions around the periphery of the required building, and d constructing the main roof structure from main beams and standard elements with main beams around the periphery of the main roof structure and with outward extensions from the main beams across the gap to the columns whereby the main roof structure is supported on the columns. The invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is a perspective view of a building at an early stage of construction; and Figure 2 corresponds to Figure 1 but shows a later stage in the construction. The building structure shown in the drawings is intended to be the main sales hall of a retail superstore but it could be used for other purposes. The horizontal dimensions of the whole building are illustrated by the extent of a concrete floor 11 in Figure 2. For purposes of simplicity, the building is shown as being rectangular but it could have a less regular shape. As best seen in Figure 1, eight peripherally positioned columns 12, 13, 14, 15, 16 r 17, 18 and 19 stand on respective concrete foundation pads 21. A further internal column 22 stands on a further concrete foundation pad 23. A main roof structure is supported on the columns. The roof structure incorporates four peripheral main roof beams 25, 26, 27 and 28 and two main roof cross beams 29 and 31. Each main beam in this example is a fabricated girder incorporating upper and lower I-section steel members and vertical braces. The arrangement of four peripheral beams and two cross beams combines to form four rectangular areas each bounded on its four sides by main beams. In this example, the position of the main roof beam 28 coincides with an edge of the building but beams 25, 26 and 27 are set in from the periphery of the building as indicated by floor 11. Thus the main roof structure, bounded by the beams 25, 26, 27 and 28 does not in general extend out to the columns intended to support it. Where necessary, beams 25, 26, 27, 29 and 31 are extended beyond the rectangular periphery of the main roof structure at one or both ends by means of triangular extensions 33. These extensions cause the beams to span the distance between columns 12 and 18 for beam 28 and columns 13 and 17 for beam 29. In other cases such as for beam 26 and column 14, the end of the beam is supported on the column by an extension 33 of another beam, in this case the beam 25. In this way, the main roof structure bounded by beams 25, 26, 27 and 28 is supported on the columns despite the fact that the main roof structure is smaller than the building and the peripheral columns are at the periphery of the floor area of this building. Column 22 supports cross beams 29 and 31 of their intersection. Some of the columns, in particular columns 12, 18 and 22 carry vertical loads only and are constituted by single I-section steel members. The other columns, in particular columns 13, 14, 15, 16, 17 and 19 are double columns each with two mutually spaced I-section vertical members braced with respect to each other by diagonal braces. Each of these double columns is capable of withstanding lateral loads in the plane of the two vertical members. Columns 13, 16 and 17 are orientated to withstand lateral loads in a direction along beam 31 and columns 14, 15 and 19 are orientated to withstand lateral loads in a direction along beam 29. In this way lateral stability is provided for the whole structure. As shown in Figure 2, the rectangular areas formed by the main beams are filled in with secondary roof elements 32 also forming part of the main roof structure. The secondary roof elements are of modular form, each module having the same standardised horizontal dimensions. In this example the modular elements constitute a space frame structure which conforms to that described in GB A- 2054694. Figure 2 shows the situation where two of the rectangular areas have been filled in completely while the remaining two areas are shown partly filled in for illustrative purposes. The dimensions of the main roof structure were selected as follows. Dimensions of 3m x 3m were selected for the horizontal extent of a secondary roof element 32 constituted by a module for a space frame. These dimensions had previously been selected as giving an optimum size, bearing in mind standard dimensions of roof and ceiling cladding panels, a desire for simple assembly without an excessive number of joints and the relationship between the size of the module and the required cross section of its individual elements to provide suitable strength. An alterative module dimension could be 2.4m x 2.4m but the modules need not be square. Working from a standard module of 3m x 3m, standardised main beam lengths of 18, 24, 30 and 36 were selected as integral multiples of the module dimension. Beams suitable for spanning these dimensions and supporting expected roof loads were pre-designed. There may be a call for main roof spans of intermediate lengths, for example 21 or 27 m. In such a case the standard design for the next larger size is selected and the beam span is simply reduced in length. The choice of a single standard cross section for two different lengths (eg 24m and 21m) helps to standardise steel sections required and thus reduces costs related to stock rationalisation. The beam design is based on its span between columns rather than its total length. The building illustrated has rectangular dimensions of 53m in the direction of beam 29 and 50m in the direction of beam 31. The side represented by beam 28 could be a simple vertical face but a Mansard style roof was required on the other three sides. A main roof structure of 48m x 48m was selected, giving a 2m gap to the periphery from beam 26 and 2.5m gaps from beams 25 and 27 to the periphery. As indicated above beam 28 coincides with the periphery. A simplified example of the kind of design employed at an edge of the building is illustrated in Figure 2. Secondary concrete foundation pads 24 carry vertical supports 36 for a wall of the building. An auxiliary upper wall beam 35 is carried on supports 36. In this example, the supports 36 are coincident with the pads 24 but with suitable ground beams spanning between pads 24, supports 36 could be carried at any point along the ground beams. A Mansard roof structure based on triangulated members 37 and 38 is supported on the adjacent main beam and is also supported on the auxiliary beam 35 so that it is in turn carried by supports 36. The simplest of designs is illustrated by members 37. For other parts of the building as shown by members 38 the Mansard roof could extend further up and inward over part of the area covered by the main roof structure. Similarly an entrance foyer or other extension of the building may project from the main line of the building and have its own pitched roof. In this example a loading bay is formed by still further supports 39 carried on auxiliary foundation pads 41 and by a corresponding Mansard structure 42. The basic structure of main beams and columns carried on foundation pads constitutes a primary chassis of the building. The main beams together with the secondary roof elements constitute the main roof structure. The addition of further structural elements constituted by auxiliary beam 35, supports 36, triangulated members 37 and 38 and where required the frame of an entrance porch or loading bay or similar addition results in a secondary chassis. The whole building is then provided with suitable walls and cladding. The walls will of course include windows and doors. Positions selected for windows and doors are almost independent of the primary chassis design in that few structural elements of the primary chassis interfere with their positioning. One would not expect to employ windows or doors at or very close to a corner of a building in the vicinity of columns 12, 14, 16 and 18. Columns 13, 15, 17 and 19 provide only a minor limitation on the degree of flexibility for the detailed design. For a smaller building which does not require a column near the centre of a main beam, there is an even wider degree of flexibility in subsequent design. The positions of secondary supports 36 can be selected to lie at the edges of doorways or away from doorways thus not interfering with design flexibility. Although the modules making up the space frame which constitutes the secondary roof elements 32 are said to be of standard design and they do have standardised predetermined horizontal dimensions, the top chords may be arranged to slope down at an angle of for example 1 in 60 from a central ridge with a corresponding variation in depth from one module to the next so that the slope is continuous to provide a sloping roof for drainage purposes. With the arrangement as described above a primary chassis to suit a particular project can be specified with little or no new design work as soon as required dimensions of the building are known. This leads to significant savings in design time and in calculating quantities and costs for quotations. At the construction stage, similar time savings are achieved.

Claims: CLAIMS 1. A building having a roof and exterior walls, a primary chassis of the building incorporating main roof beams supported on columns, a main roof structure extending over most but not all of the building as defined by its exterior walls and comprising main beams extending along the outer periphery of the main roof structure and secondary roof elements supported by the main beams, the columns being positioned at the exterior walls of the building, extensions of main beams beyond the periphery of the main roof structure connecting the main beams to the columns whereby the columns support the main roof structure, outer parts of the roof beyond the main roof structure being supported on main beams and on upright supports located along the line of the exterior walls of the building. 2. A building as claimed in Claim 1 also incorporating at least one internal main beam extending across the building within the main roof structure and at least one internal column supporting an internal main beam within the main roof structure. 3. A building as claimed in Claim 1 or Claim 2 wherein at least one column is constructed to resist lateral loads in one direction and at least one other column is constructed to resist lateral loads in another direction. 4. A building as claimed in any one of the preceding claims wherein each main roof beam comprises upper and lower members and braces between them. 5. A building as claimed in any one of the preceding claims incorporating triangulated members forming an outer part of the roof beyond the main roof structure. 6. A method of producing a building of the kind comprising a primary chassis incorporating main roof beams supported on columns and a main horizontal roof structure comprising said main roof beams and secondary roof elements, the method comprising the steps of: a pre-selecting a standard design of secondary roof element having pre-selected standard horizontal dimensions such that a main roof structure of main beams and standard elements can be built with horizontal dimensions representing integral multiples of the standard horizontal dimensions, b selecting main roof structure dimensions as a multiple of the standard element dimensions to fit within the required building periphery with a gap between at least part of the main roof structure and said periphery, c erecting columns of a primary chassis to support a main roof structure at positions around the periphery of the required building, and d constructing the main roof structure from main beams and standard elements with main beams around the periphery of the main roof structure and with outward extensions from the main beams across the gap to the columns whereby the main roof structure is supported on the columns.

Inventors: THOMPSON KENNETH WILLIAM, THOMPSON, KENNETH, WILLIAM
Applicants: ASW CUBIC STRUCTURES LIMITED, THOMPSON KENNETH WILLIAM, ASW-CUBIC STRUCTURES LIMITED
Application year: 1993
Main classification: E04B1
IPC codes: E04B1, E04B7