The construction materials industry contributes significantly to global greenhouse gas (GHG) emissions due to energy intensive manufacturing processes and complex supply chains. At the same time, regulatory frameworks such as CSRD, ESRS E1, and ISO 14064-1 require organizations to provide transparent, traceable, and auditable environmental data. However, many multisite manufacturing organizations still rely on fragmented spreadsheet based reporting systems, resulting in inconsistent environmental reporting, incomplete submissions, and weak auditability, and labour intensive GHG calculations. The study contributes to Design Science Research (DSR) and environmental information systems research by developing and evaluating a governance oriented digital reporting artifact for multisite greenhouse gas (GHG) emissions management. Rather than focusing solely on software implementation, the study formalizes a set of transferable design principles integrating structured sustainability metrics, validation rules, role-based workflows, audit trail mechanisms, and centralized reporting governance. The artifact was demonstrated and evaluated within a multisite construction materials manufacturing organization using measurable governance indicators including reporting duration, data completeness, traceability coverage, and calculation error frequency. The findings indicate that the combined interaction of governance controls and digital workflow configuration may support improved environmental reporting consistency, transparency, auditability, and operational efficiency within the studied organizational context. The study contributes a transferable socio technical framework for digital sustainability reporting applicable beyond the specific software platform used in the organization case.