[abh19]

Like the others said, I would assign those to a "waiting for" context. Note that you can put the entire context on hold so the actions don't show up as available actions in your next actions lists. Then when the pump house is built, you go and manually change the context from "waiting for" to whatever the context of the action really is. Unfortunately, this transition isn't automatic, but it does preserve the correct dependency structure. You can set up a perspective to look for "stalled" projects (projects with no available next action) and flip to this perspective daily to catch any of those "waiting for" tasks that become doable.