The renovation of existing buildings requires decisions to be made with limited information on the condition of the building, while simultaneously taking into account environmental requirements arising from legal regulations, funding conditions, and multi-criteria certification systems. The aim of this article is to develop a structured approach to identifying and integrating these requirements into the decision-making process at the early stage of renovation project preparation. The study was conducted using a qualitative analysis of documents and scientific literature. The identified requirements were classified according to their source and basis for application, area of impact, information required for their assessment, required evidence, and stage of identification, and their potential influence on project decisions was then determined. The results were compiled into an environmental requirements integration matrix, and the key information and parameters required for their assessment were identified. The analysis showed that requirements originating from different sources may concern the same areas but differ in the scope of information required, while some data may be used to assess several interrelated requirements. The point at which a requirement is identified does not necessarily coincide with the point at which compliance is demonstrated; therefore, requirements affecting the scope of renovation or the selection of solutions should be identified before the corresponding decisions are made. The proposed approach can support renovation project preparation at an early stage of the decision-making process.