The foundations ought to be so designed that all settlement of the structure will be avoided, and they must be ample properly to support the building. If tunnels or other deeper structures are or will be installed, the foundations should be so designed that they will be undisturbed.
1 he question of the advisability of equipping the building with a power and lighting plant is one of great importance. In general, if current from a public utility corporation can be obtained at a reasonable rate for power, it is better to eliminate the power plant, operating the elevators by electricity and allowing the tenants to buy their current for lighting. There are buildings in which the owners claim that their plants show a good profit through the sale of current to the tenants, but these -are exceptions, and for each building of this kind there are certainly two or three to be found where the power plants have been shut down and current is now supplied by the Public Utility Corporation. By the omission of the plant the initial cost is reduced, expensive operation, labor troubles, breakdowns and difficulty in obtaining sufficient coal are avoided and depreciation reduced. This portion of the building is subject to very rapid depreciation, as has been shown by long experience.
The elevators are of great importance to the success of the building. The number should be sufficient for the peak load, but this peak load is subfect to great variation caused by the character of the tenants. Those tenants who occupy large spaces and have a large clerical force, such as railways, large manufacturers, school boards, etc., seriously affect elevator service. Unless arrangement can be made between owner and tenant, providing that the employees leave and arrive, particularly at the noon hour, in regulated relays, the elevators, which during practically all other hours of the day are more than ample, may become inadequate. This always reflects, on the minds of the public and affects the reputation of the building. The use of the upper floors for clubs, particularly lunch clubs, has this same effect. Elevators should have good speed, be equipped with signals to reduce stops to a minimum and thus conserve both time and current. The elevator cabs should always be at least as wide as they are deep, and, if possible, from 20% to 50% wider. The doors should open to two-thirds of the width of the cab. This insures quick filling and emptying of cabs, conserves time and thus reduces the total of service. For the ordinary office building cabs that will hold twelve to fourteen people will show the best results, rather than larger or smaller cabs. Thus the cabs will have from 28 to 32 sq. ft. of area inside measure
ment arranged 4 8 deep by 6 o to 4 8 deep by 7 o wide.
The interior treatment of the building, to a large degree, determines its character and also its worth as an investment. The building that has durable finish and is a little better finished and equipped than its neighbors will not be outclassed so rapidly by newer structures, and will have a longer commercial life. The tenant is affected mostly by the appearance of the elevator lobby, corridors, public utilities and finish of his offices, the character of the plumbing and heating, arrangement of lighting outlets and convenience to elevators, stairs and public utilities.
The investment problem becomes largely the deciding factor in the equipment of the interior of the building. It is here that success or failure is often determined, and this also has much to do with the commercial or useful life of the building.
The rentals obtainable in a locality must be the deciding factor in selecting the finish of the building. Certainly the standard of finish of a building where $1.25 to $1.50 per sq. ft is to be expected must be lower than where higher rentals prevail. There is a simple rule that governs most successful buildings. The rentals of the first story and basement should pay the taxes on the land, 5% interest on the land (or the ground rent in case of a long lease) and the insurance on the building as a minimum. It will then appear that when this minimum only is obtained the upper stories must be leased for $1.25 per sq. ft. to pay a small return on the most economical building possible. This seems a fair rule, as an analysis of rentals will show. On various streets in cities where first story rentals vary greatly, the office rentals remain usually about the same and the high first story rentals occur where the land value is highest. With this rule in mind the importance of determining the probable rentals of the first Story of a proposed building becomes evident, and the necessity of a study of the interior treatment with relation to the rentals expected.
Some of the vital elements of the interior treatment are: Number of elevators, location of public toilet rooms, treatment of corridors, character of plumbing fixtures, heating system, floor treatment and kind and finish of woodwork.
The number of elevators depends on the total square feet of renting space above the first story, modified by the class of tenants and the relative size of the offices; the maximum number should be based on 20,000 sq. ft. of renting area per elevator and the minimum on 27,000 sq. ft. In both cases this only applies where the total renting area exceeds 60,000 sq. ft. The height of the building