Pergola, Patio Cover or Pavilion?

A pergola has an open roof of beams or slats for partial shade. A patio cover has a solid roof, usually attached to the house, that also keeps rain off. A pavilion is a freestanding structure with a solid roof. HomeGuide puts pavilions at $35 to $60 per square foot before foundation work, and an aluminum patio cover at $20 to $50. In Boise, the solid-roof options carry snow, so they are designed for the city's 25 psf minimum roof snow load, and any attached cover needs a permit.