Collaborative construction is a main application in the field of autonomous systems. An interesting subject in the area is the construction of realistic human-like architecture. However, the task of building a human-like architecture is nontrivial since the construction is a real time process without human supervision. In this paper, we present a collective building algorithm based on stigmergy. A swarm of virtual agents construct edifications which resemble basic features in human-like architecture. The algorithm maps sensory information to appropriate building actions.