The character of the work, which must be determined by the spirit and letter of the specifications, will be the controlling factor in fixing costs. In the case of material, where the requirements are exacting and demand a grade of material which can only be obtained by special selection, an extra rate must always be considered. This is best secured by contracting with the lumber merchants for the supply of the material to strictly accord with the architect's stipulation. The matter of labor, however, is one on which too much care and forethought cannot be expended. What may be considered satisfactory work by one contractor would be considered inferior by another, and this often accounts for the great differences in estimates.

Cost Per Square Foot

For all classes of materials that enter into the general framing and covering of a building, a close estimate may be made by analyzing the cost per square foot of surface; that is, the cost of labor and materials - studs and sheathing in walls, joists and flooring in floors, etc - required for a definite area should be closely determined, and this cost, divided by the area considered, will give the price per square foot. If the corresponding whole area is multiplied by the figure thus obtained, the result will, of course, be the cost of that portion of the work. While it is usual to adopt a uniform rate for the various grades of work, a careful analysis will show that roof sheathing in place more than wall sheathing, owing to its position; and that the studs in walls and partitions cost more than floor joists, as they are lighter and require more handling.

The following example shows how to determine the cost per square foot of flooring, and indicates the general method to be pursued in like cases. The area used in calculation is a square of 100 sq. ft. The cost of labor is estimated at 50 per cent, of that of the materials, which experience has shown to be a very close approximation to the actual cost of general carpenter work.

Cost Of Finished Floor Per Square

Joists, hemlock, 8 pieces, 3 in. X 10 in. X 10 ft. = 200 ft. B. M. at $14.00 per M...................................................

$ 2.80

Bridging, hemlock, 7 sets, 2 in. X 3 in. X1. ft. 4 in. = 9 ft. B. M. at $14.00 per M...................................................

.13

Rough flooring, hemlock, 7/8 in. thick, laid diagonally, 100 ft. + 25 ft..+ 10 ft. = 135 ft. B. If. at 817.00 per M

2.29

Finished flooring, white pine, 7/8 in. thick, 125 ft. B. M. at $22.00 per M.......................................

Nails, about 3 lb. at 81.80 per 100 lb................................

.05

Labor, 50 per cent. of cost of materials.............................

3.99

Total cost for 100 sq. ft.................................................

$12.01

Cost per square foot, 812.01 /100 = 12 cents.

A similar method may be followed in estimating the cost of interior finish, paneling, doors, etc.