In this paper we propose a methodology for the construction of 3D electronic institutions. 3D electronic institutions are normative environments where software and human agents can participate and collaborate in a joint 3D Virtual World. The proposed methodology covers the specification of the institutional rules, as well as the design and visualization of 3D environments for the specified institution. It is also supplied with a set of graphical tools that facilitate the development process on every level, from specification to deployment. The resulting system facilitates the direct integration of human users into Multi-Agent Systems as they participate by driving an avatar in the generated 3D environment.