Parametric design can be used for structural design. This approach has someclear advantages compared to the conventional point-based approach using differentComputer Aided Design (CAD)-software, especially in early stage of design. Since themodel is parametrically defined, alternate designs, that are within the scope of theparametric definition, can be explored with little effort from the user compared tothe point-based models. In this way, optimization routines can be used to make moreinformed decisions about the design. Pipe bridges usually have a similar design that issuitable to be defined parametrically.The aim of the thesis is to automate the modeling of pipe bridges in the earlystages of design, to make an integrated analysis and to optimize the structure withregard to material cost and carbon dioxide equivalent-emissions as well as mass ofthe structure. Further, to investigate in what way these objectives are correlated.This thesis improves an existing grasshopper script used to design pipe bridges andimplement an automatic generation of a Bill of Quantity (BoQ).The results of the thesis case study suggests that there is potential in usingoptimization with parametric design to minimize the cost of pipe bridges. With a goodparametric design definition alternate designs can be explored with little effort fromthe user. This benefit to speed up the design process, and allowing the designer towork with adaptable design, could be reasons to turn to a parametric design method.It should also be stressed that this thesis suggests a correlation between the cost of thestructure and the carbon dioxide equivalent emission from the structure. Meaning thatwhile minimizing emissions one could also be minimizing the cost.