House consolidation is a process of self-help building where house state is improved progressively from initial precarious conditions. It is conducted by low income households located at informal land developments in the periphery of Lima, Peru. An agent-based analogy of the consolidation system is devised to provide an experimental setting at block scale. Initial states are grown up towards consolidated conditions through diffusion within a network of interacting households. Emergent spatial and temporal trajectories of state transition resemble actual process. The study of influence between neighbors allow to investigate two features of the decision to upgrade: income stream and family needs.