Try the comparison
The building envelope separates indoor conditions from outdoor or unconditioned spaces. A first exercise needs a smaller working boundary than the whole envelope. Choose one accessible location and a specific question. Bounded work makes it possible to notice unintended effects and to stop when the conditions change.
This course supports observation and planning for modest accessible repairs. It does not teach attic access, removal of trim, work inside electrical fittings, fuel-appliance adjustment or structural repair. A small project is defined by its risk and access as well as its size. Even a tiny opening beside a hot flue belongs outside a beginner repair.
Supplied case
Rowan lists a ground-level door edge, an attic chimney opening and a loose electrical outlet cover. There is time for one short observation session.
Choose the first observation location and record two exclusions.
Attempt first, then compare the worked response
Observe the ground-level door edge. Exclude the attic chimney opening and work on the electrical outlet.
The door permits a visible, accessible check. The other locations introduce access, heat or electrical hazards that this course does not train you to manage.
Check your response: A defensible boundary names what you will inspect and what you will leave for an appropriate professional.
Concept reference: Natural Resources Canada, Keeping the Heat In.