This document proposes a model for charities and organizations to optimize their social impact. It argues that many currently use a "deficit model" that focuses on offsetting perceived negative impacts rather than maximizing benefits. The proposed "social benefit" model emphasizes measuring an organization's "structural impact" from its core activities. Additional and complementary activities should complement rather than detract from this. The document advocates for "additional" research and innovation to continually improve social impact through refined core activities. It provides examples from the social housing sector to illustrate how this framework could be applied.