The need for economic analysis of building walls is discussed, and the factors influencing the ultimate cost of exterior walls are studied. The present worth method is used to analyze three types of exterior non-loadbearing panel or curtain walls. Anticipated costs are expressed in terms of their present value per square foot of wall area. The financial aspects of the value of money, depreciation, price increases and taxation are reviewed. Initial wall costs are estimated. Formulae are given for calculating the influence of depreciation, speed of erection, heating, air conditioning, illumination, real estate taxes, and usable floor space occupied by the wall. Fourteen examples are given to demonstrate calculation methods for anticipated costs. Typical cases are cited to show the effect of insurance rates and the cost of supporting walls. Maintenance and ultimate salvage value are considered. Twenty-four references helpful to the designer are cited. Charts and tables are provided to assist the designer in computing ultimate wall costs. The authors conclude that aesthetics, engineering and economics are equally important to good architectural expression, but that the variation in the ultimate costs of typical walls may be five hundred percent or more. (RK)