To reduce resource consumption and ensure an adequate level of quality, both in manufacturing and in the installation of metal it is necessary to investigate a composite index of constructability, and a composite index of quality, for subsequent use in structural design. The purpose of this scientific research is to develop composite quality index.

At a development of the composite quality index qualimetry conception was used: all properties characterizing quality were found, the hierarchical structure was made, indicators on the third level properties (offered by author) and their weight at each level (expert poll) were defined. The formula of composite quality index of steel auxiliary bar structures was development.

The composite index of quality can be used together with the composite index of constructibility at the design stage for evaluating and improving auxiliary bar structures. It is necessary to compare different variants of steel structures because the quantity of used resources at manufacturing and installation can pass in quality, and quality can pass to quantity of used resources.