To me, you plan via projects: This is what you want to achieve. All actions come from projects. One time projects or maintenance, recurring projects, single actions, whatever.
Each action whithin a project requires certain tools, people, places, energy, time of day etc to be performed. These are represented by contexts. Contexts need not be mutually exclusive, a task may need several of them available concurrently to perform a task.
At any given time, when I have time available for action, I ask myself:
¿What can I do now, given my present ‘context’ (= circumstances) to advance to my goals (my projects)
So if I am in the car, after work, downtown, with an hour to spend, I would go see list all things that I can do in this particular context(s)
And so on,
So, again, the planning process is basically project driven, and the execution can be context driven.
¿Does this make sense to you?
So in your case, to me repair the garage stairs is a project, part of which will be done at home, part of it on the phone, part of it in the store… with a certain tool, aided by a certain people etc etc. Same with house chores or house packing. These are projects, not contexts, to me anyway,