Passive solar design is an architectural approach that utilizes natural sunlight to heat and light buildings without relying on mechanical systems. This design focuses on strategic placement of windows, walls, and floors to capture solar energy, maximizing warmth during winter and minimizing heat during summer. Key elements of passive solar design include thermal mass, which absorbs and stores heat, and insulation, which helps maintain comfortable indoor temperatures. By incorporating features like overhangs and strategically placed windows, buildings can enhance energy efficiency and reduce reliance on heating and cooling systems.