What sizenat gas furnace for 2500 sq ft house?

For a 2,500 square foot house, the size of the natural gas furnace typically needed is around 80,000 to 100,000 BTUs (British Thermal Units) per hour. However, the exact size may vary based on factors such as insulation quality, climate, and specific heating needs. It's best to consult with an HVAC professional who can perform a load calculation to determine the most efficient furnace size for your home.