Greenhouse Sizing Calculator

How It Works

A greenhouse extends your growing season by trapping solar heat and protecting plants from frost, wind, and pests. The key decisions are size (match to your growing ambitions), heating (critical in zones 3-6), and ventilation (prevents overheating and disease). Hobby greenhouses range from $500 hoop houses to $10,000+ glass structures. Double-wall polycarbonate panels offer the best balance of insulation, durability, and cost for most home gardeners. In cold zones, heating is the biggest ongoing expense -- consider a small propane heater with thermostat. In warm zones, shade cloth and ventilation fans are more important than heating. Plan for at least one exhaust fan and one intake vent for air circulation.