Tabriz Recreational Center is a sustainable sport and leisure complex located in Tabriz, developed as a low-energy, LEED-oriented design built around six guiding goals: energy, health, greenhouse gas reduction, water management, economic efficiency, and resilience. The project began with a comparative site-selection study of four candidate sites across the city, evaluated through SWOT and a LEED-based scoring system, followed by detailed site analysis of solar radiation, daylight, prevailing winds, neighboring context, traffic, and acoustic conditions to inform building placement and the initial plan. The complex houses a range of facilities including a gym, main pool, squash halls, sauna, jacuzzi, body-fitness spaces, locker rooms, a café and restaurant, and administrative areas, arranged according to a spatial program and relationship diagram and tested through several massing alternatives. Passive strategies drive the design, with a central courtyard, skylights, clerestories, a pitched roof, and a double-skin facade combined with a 40% window-to-wall ratio and dynamic shading tuned to each orientation. These are paired with an optimized building envelope, a ground-source heat pump HVAC system supported by a cooling tower, and rooftop and parking-canopy photovoltaic panels sized to offset the building's electricity demand. Compared to the baseline, the design improves thermal comfort by roughly 50%, reduces primary energy use by about 31% and total energy demand by 48%, and lowers embodied carbon by around 29%, positioning the complex to potentially achieve LEED Gold certification.