This section is from the book "Cyclopedia Of Architecture, Carpentry, And Building", by James C. et al. Also available from Amazon: Cyclopedia Of Architecture, Carpentry And Building.
While these matters are under consideration by the owner, an examination of the proposed site will be profitable, to gain necessary information in regard to party walls and the condition of adjoining property. The nature of the soil, the location of sewers and other underground works, will be factors in the proposed construction, and all data relating to these matters must be recorded and carefully preserved.
As soon as the instructions of the owner, or the recommendations of the architect, have been definitely adopted, the construction of the building will be laid out. As the problem will resolve itself into the disposition of a greater or less number of isolated points of support, instead of the ordinary continuity of walls, it will be necessary to study the construction at the same time with the laying out of the offices, in order to bring the necessary vertical supports as much out of the way as possible. Another consideration will be the thickness of the floors. As the number of floors is sure to be considerable, it will readily be seen that an excessive thickness will result in considerable loss of height; and. if the thickness of each floor can be kept down to a reasonable rate it may be the means of obtaining a story more for rentable purposes which is a matter worthy of consideration.
These factors, which do not enter so strongly into the problems which we have previously considered, must have careful consideration in constructing mercantile buildings of the class which we have now before us; and upon their skillful employment will depend the success of the enterprise.
In the bringing together of these elements to form a whole composition, certain external elements must be considered. Among these are ease of access, the maximum of light, rentable area, ease of rearrangement to suit tenants, and the minimum of cost. Ease of access will require that the elevators and stairs shall be placed in direct and obvious connection with the entrances and as nearly as possible at the level of the sidewalk, readily seen on entering the building or on leaving the offices to which they give access. The position of the elevators will be of more importance than the stairs, as the latter will be little used in high buildings. To obtain the best light possible it will be well to provide that the areas (which will be a necessity in a building in the interior of a block or in a wide building on a corner) shall have a general direction north and south. These areas should not be narrower than six feet and should contain windows as large and as near the ceiling as possible, and the rooms should be as nearly rectangular as may be, thus avoiding dark corners.
The structural conditions will enter more or less into the arrangement of the offices, as already suggested, and to this must be added ease of adjustment to the needs of the average tenant. The unit of size and arrangement of the offices should be such that a tenant who wants a single office may have one of average size, or a tenant who wishes, may have the whole floor, except the minimum of space necessary for toilet rooms, elevators and stairs.
When the character of the building and the general divisions of the floor space have been established, the location and design of the columns, the kind of wall and floor construction, and the size and spacing of floor beams and girders must be determined. The location of the columns and girders will be determined by the size and shape of the floors, the position of present or future partitions, the floor loads, and other considerations which arise with different locations and uses. In general, the most economical spacing of columns and girders will vary from 14 feet to 16 feet.
The spacing of the floor beams will depend upon the system of floor construction used.