The aim of this study is to construct a fundamental theory of evaluation and decision in building production.

It is pointed out in the first part that there are two viewpoints of Axiomatic Theory and Measure Theory and we must give Multi-Value for each building system from each value-feeling of individual.

Some systematic judgment methods without objective function are proposed in chapter 1. It is possible that given building systems denoted with multi-dimensional vectors are distinguished into better systems and inferior systems by those methods.

In chapter 2, a mathematical model of building production and the concepts of individual optimization and total optimization are given. Furthermore a dilemma phenomenon in building production is shown. Scenario-Matrix Method is proposed in order to solve this dilemma.