This study focuses on addressing the challenge of finding optimal sizing and management strategies for Hybrid Renewable Energy Systems (HRES) in the building sector, with the aim of reducing greenhouse gas emissions and dependence on fossil fuels. The research proposes a Multi-Agent System (MAS) based approach for the optimal sizing and management of HRES to meet the electricity demand of green buildings in Algeria. The HRES configuration includes components such as photovoltaic panels, wind turbines, batteries, and either a diesel generator or utility grid connection, depending on the specific application.The study begins by formulating the multi-objective problem as a single-objective one. To solve this problem, a Particle Swarm Multi-Objective Optimization algorithm (MOPSO) is developed using MATLAB software.