1. A computer based method for realizing a building system, the method comprising: receiving input related to customer needs for a building system, the input being received through a user interface at a remote client device and being expressed in a formal description language; generating multiple different business models from the customer needs input, wherein the business models define, in a functional language, types and volumes of services that will be provided within the building system to satisfy the customer needs; generating multiple different spatial arrangements from at least one of the business models, wherein the spatial arrangements define a form and shell of the building system, a block and stack of the building system, and room locations within the building system; generating multiple different systems integration designs from at least one of the spatial arrangements, wherein the systems integration designs define three dimensional spaces of infrastructure of the building system; tracking dependencies between the customer needs, the business models, the spatial arrangements, and the systems integration designs.