How many btu's does it take to keep a 1500 square foot walkout basement above freezing?

To keep a 1,500 square foot walkout basement above freezing, the BTU requirement can vary based on factors like insulation, local climate, and desired temperature. On average, it takes about 30 to 50 BTUs per square foot to maintain a comfortable temperature, translating to approximately 45,000 to 75,000 BTUs for the entire space. Proper insulation and sealing can significantly reduce this requirement. It's best to consult a heating professional for a more accurate assessment based on specific conditions.