Costs for ordinary cellars were reported for most sections as varying from 50 cents to $1 per square foot of floor space. The cost per square foot is, of course, less for a large than for a small cellar, other things being equal. Easy excavation and low-cost materials also make for low unit cost. Costs of nearly $2 per square foot were reported in some sections where the ground-water level is high and cellar walls and floor must be carefully waterproofed. In sections where cellars are not ordinarily used the cost of the foundation was reported as part of the cost of the house superstructure. SUPERSTRUCTURES AND PORCHES Reported costs of one-story frame superstructures, including heating, plumbing, and lighting equipment ordinarily used in the locality, ranged from $1.25 to $2.25 per square foot of floor space in the South, from $2.25 to $3.50 in the West and Southwest, from $2.50 to $4 in the North, and from $3 to $4.50 in New England. Costs in Maryland, Virginia, and West Virginia and in a narrow belt along the east coast, including Florida, were reported from $2 to $3.25, and in the timber-producing sections of the Northwest at about $2 per square foot. Costs in any locality are influenced by local factors, generally being relatively high near cities and in thickly settled sections and relatively low in places where there are local supplies of lumber or other materials. Differences in cost between the various sections are due to differences in the kinds of houses built, as well as to differences in material costs and wages. The typical house in the North is much more compact and substantial and provided with more expensive heating equipment than the typical house in the South. The cost per square foot of floor area of two-story frame houses was reported as being 5 to 15 percent less than that of one-story houses in the same locality. The costs of typical masonry superstructures were generally reported at $2 to $3 per square foot of floor area in the southern third of the United States, from $3 to $4 per square foot in the central third, and more than $4 per square foot in the northern third of the country. There were many variations from these general levels, however, costs of about $2 per square foot being reported in many localities in the States bordering on or south of the Ohio River. Costs reported for counties along the Atlantic and Gulf coasts were generally higher than for those in the interior. Little difference in cost per square foot of floor area in one-story and in two-story masonry houses was reported. The higher costs reported for masonry houses as compared with frame are probably due in part to better grades of finish and equipment used in the masonry houses. The costs per square foot of floor space of open porches were reported as being about half the costs per square foot of floor space in one-story houses of similar materials. ESTIMATING BY UNIT COSTS