Hoop House Calculator. A hoop house is a tunnel-shaped greenhouse covered in plastic or glass, used to extend the growing season for plants. Enter your hoop house length, width, height, and eaves height, then select a covering material and provide your outside low temperature and desired inside temperature to get the total surface area, required heater size (BTU/hr), estimated covering cost, and floor area. Also try the use the Garage Door Size Calculator.
A hoop house or greenhouse is a transparent structure made from materials like polyethylene, glass, or polycarbonate that creates controlled growing conditions for plants. It maintains optimal temperature, humidity, and protects crops from harsh weather conditions. See also our Chicken Coop Size Calculator.
Surface area is calculated by adding the areas of all surfaces including the curved or angled roof sections, end walls, and side walls. For hoop houses, this includes calculating the curved surface area of the hoops plus the end wall areas.
Heater size depends on your greenhouse surface area, covering material's insulation properties, and the temperature difference you need to maintain. Generally, you need 20-40 BTU per square foot depending on climate and covering type.
Common options include single or double-layer polyethylene (cheaper but less durable), polycarbonate panels (good insulation and durability), and glass (excellent light transmission but more expensive and fragile).
Key factors include surface area, covering material R-value, outside temperature extremes, desired inside temperature, wind exposure, and thermal mass. Better insulating materials reduce heating needs significantly.
Costs vary by material: polyethylene film costs $0.10-0.30 per sq ft, polycarbonate panels cost $2-4 per sq ft, and glass ranges from $2.50-10 per sq ft depending on thickness and quality. You might also find our calculate Window Size Rough Opening Width useful.