Abstract
The total cost of the exterior skin of the building is discussed in this report, relating with building forms. The quantitative study on the building elements made out the relation between exterior skin area and building forms in the following formula. [numerical formula] R : roof area (m^2), E : exterior wall area (m^2), A : total floor areea, n : number of stories h : floor height, k : ratio of sides in typical floor This relation is shown in Fig.5 by graph. Then the unit cost of wall and roof were introducod this formula. When "A" is fixed, "n" that wakes exterior skin cost minimum is given hereunder, [numerical formula] C_r : unit cost of the roof (yen/m^2), C_e : uint cost of the exterior wall (yen/m^2) This means that (C_r/C_e)^<2/3> times "n" which make the total exterior skin area least, make the total exterior skin cost last Actuay, the exterior wall cost slides according to the "n" of the building. But this extent is very much difficult to seize. Because, there is no building which have same facade but have different "n". According to the economic study on heigh rise building by J. B. A, the relation between exterior wall cost and "n" are as followes in the same fasade. C_e=180n×19, 600 Using this factor, more acculate estimation on "n" which gives minimum exterior skin cost is possible, but "n" can not be solved generally in this case, may be solved unmerically by E. D. P. only.
