This paper presents a roadmap for the implementation of Renewable Energy Communities (RECs), which are innovative energy systems based on a new model of renewable energy production, consumption, and sharing. The objective is to examine the regulatory framework of Member States and present a standardized procedure for the implementation of a REC, an aspect not yet covered in scientific literature. The roadmap includes four main phases: a feasibility study involving an energy analysis of end users' consumption and a general assessment; the aggregation of members as producers, consumers or prosumers forming a legal entity, considering different funding opportunities; the operating phase, involving plant construction and project validation by national authorities; and the technical and economic management phase. The dynamic structure of the roadmap allows for adjustments to accommodate different regulatory contexts, member typologies, and project aims. The paper discusses the regulatory framework in Europe, focusing on the directives in several Member States. It presents a standardized roadmap that encompasses all the main phases to be followed for REC implementation in each country, with adaptations according to national laws. Each phase is thoroughly examined in a comprehensive way, from the feasibility study to the management of the community. The paper also compares the legal settlement provisions for the transposition of RECs, emphasizing the fundamental scopes and features of different legal forms. It assesses and compares funding opportunities according to the typology of investors and the typology of investments for REC projects. The paper formulates an energy, environmental, economic, and social KPIs to evaluate such different features of RECs. The paper also discusses the implementation of RECs in various European countries, including Spain, Germany, Ireland, Greece, Portugal, Austria, Italy, Latvia, Poland, and Bulgaria. It presents a standardized procedure for implementing a REC, which has been developed through a comparison with professionals involved in real projects, taking into account the features and problems they encountered during the creation process. The main phases of the process are: feasibility study, aggregation, operating phase, and management. These phases, along with their sub-phases, are presented in Fig. 3. Each step will be analysed in detail within this section. The starting point should certainly be acquiring knowledge of the regulations, analysing the necessary requirements and subsequently being able to operate accordingly. The paper also discusses the use of various software tools for sizing renewable energy systems, including HOMER Pro, TRNSYS, iHOGA/MHOGA, Hybrid2, and RETScreen. The paper concludes with a summary of the study and presents future developments.This paper presents a roadmap for the implementation of Renewable Energy Communities (RECs), which are innovative energy systems based on a new model of renewable energy production, consumption, and sharing. The objective is to examine the regulatory framework of Member States and present a standardized procedure for the implementation of a REC, an aspect not yet covered in scientific literature. The roadmap includes four main phases: a feasibility study involving an energy analysis of end users' consumption and a general assessment; the aggregation of members as producers, consumers or prosumers forming a legal entity, considering different funding opportunities; the operating phase, involving plant construction and project validation by national authorities; and the technical and economic management phase. The dynamic structure of the roadmap allows for adjustments to accommodate different regulatory contexts, member typologies, and project aims. The paper discusses the regulatory framework in Europe, focusing on the directives in several Member States. It presents a standardized roadmap that encompasses all the main phases to be followed for REC implementation in each country, with adaptations according to national laws. Each phase is thoroughly examined in a comprehensive way, from the feasibility study to the management of the community. The paper also compares the legal settlement provisions for the transposition of RECs, emphasizing the fundamental scopes and features of different legal forms. It assesses and compares funding opportunities according to the typology of investors and the typology of investments for REC projects. The paper formulates an energy, environmental, economic, and social KPIs to evaluate such different features of RECs. The paper also discusses the implementation of RECs in various European countries, including Spain, Germany, Ireland, Greece, Portugal, Austria, Italy, Latvia, Poland, and Bulgaria. It presents a standardized procedure for implementing a REC, which has been developed through a comparison with professionals involved in real projects, taking into account the features and problems they encountered during the creation process. The main phases of the process are: feasibility study, aggregation, operating phase, and management. These phases, along with their sub-phases, are presented in Fig. 3. Each step will be analysed in detail within this section. The starting point should certainly be acquiring knowledge of the regulations, analysing the necessary requirements and subsequently being able to operate accordingly. The paper also discusses the use of various software tools for sizing renewable energy systems, including HOMER Pro, TRNSYS, iHOGA/MHOGA, Hybrid2, and RETScreen. The paper concludes with a summary of the study and presents future developments.