PlanGrid co-founder here. It's definitely useful for a project of any size, but the value definitely scales non-linearly with the size of a project.
If nothing else, if you have a construction project that has paper plans, PlanGrid is the best way to make them digital, shareable, usable by multiple people.
If nothing else, if you have a construction project that has paper plans, PlanGrid is the best way to make them digital, shareable, usable by multiple people.