Most current VE applications make use of well-known 3D interaction techniques, such as ray-casting or the Go-Go technique. Such techniques, however, were designed generically, without considering the context of use. We argue that the design of 3D interaction techniques should take the application domain into account. In our work, we have developed interfaces for a VE application for structural engineering, including interfaces for cloning, a domain-specific task. We designed and compared six cloning interfaces. The techniques designed using domain characteristics resulted in significant performance gains and a better workflow. In addition, those techniques designed from scratch using domain characteristics were generally superior to generic techniques that were modified to consider domain characteristics. Finally, we found that the transition time between actions in these complex interfaces was a major bottleneck for task performance.