The Triple Bottom Line (TBL) framework defined by Elkington in 1998  proposed three aspects of sustainability: economical, environmental and social. However, several researchers have observed that further studies are needed to guide people and companies on how to achieve sustainable development. Specifically, many gaps are found in trying to implement social sustainability in processes within companies. This study aims to contribute to the integration of social sustainability in processes, with a specific focus on companies that fabricate and deliver post-disaster temporary housing. Our study is based on Value Stream Mapping (VSM) methodology, which previous research studies have identified as one of the main lean methodologies to analyze and identify waste in processes. Existing approaches based on VSM only attempted to integrate social sustainability of internal stakeholders into it. The research described in this paper aims to extend previous studies by integrating social sustainability of external stakeholders in companies processes using VSM methodology. The analyzed system is the fabrication and delivery of panelized post-disaster temporary housing solutions where the post-disaster context is used to identify processes as well as internal and external stakeholders. Subsequently stakeholders expectations and indexes that relate them with the outcomes of companies processes are defined using existing research studies on social impact and on disaster management. Then, a model is proposed to integrate social sustainability of external stakeholders on VSM methodology. Finally, the proposed model is tested within an existing NGO that fabricates and delivers panelized post-disaster temporary housing in Chile.