Sustainability impact assessment in early-stage ventures

Sustainability-oriented startups are increasingly expected to contribute to addressing complex sustainability challenges. Alongside economic viability, they are required to demonstrate measurable environmental and social impact from the earliest stages of development. However, early-stage contexts are characterised by evolving business models and limited information, which complicate robust sustainability impact assessment. Despite this growing pressure, most existing approaches have been developed for established companies, where formalised structures and consolidated data enable more stable evaluations. This thesis addresses this gap by developing a structured sustainability impact screening approach tailored to early-stage startup contexts. Grounded in the Design Research Methodology (DRM), the study combines a systematic literature review leading to the identification and analysis of 21 studies with the operationalisation of a multilevel sustainability impact framework. The review highlights considerable heterogeneity in how sustainability impact is conceptualised and assessed in early-stage contexts. While impact considerations span micro, meso, and macro levels, the link between sustainability performance, stakeholder value, and system-level impact is often implicit rather than formally modelled. In addition, rebound effects are rarely incorporated into quantitative assessment structures. To address these limitations, this thesis proposes an adapted IPAT-based formulation extended to incorporate rebound effects and translates it into a prototype screening tool. The tool enables startups to estimate the environmental impact change of their solution compared to existing configurations while identifying and quantifying potential rebound effects. Tested through four diverse startup cases, the application of the tool provided structured support for early design and strategic decisions, while enabling the development of quantitatively grounded and credible sustainability impact narratives for investors and stakeholders.