It’s 2 a.m. on a frigid January night when the power goes out during an ice storm. Whether you face a minor inconvenience or a genuine crisis depends on your home’s weatherization and your preparation. October is a golden window to get ready before winter’s first blast. This guide can help you prepare, whether you rent an apartment or own a house.

Renter-friendly weatherization (no permission required)

Test for air leaks. Walk through your home on a windy day with lit incense, moving it along window frames, door edges, outlets and baseboards. When smoke wavers or gets sucked toward cracks, mark these spots with painter’s tape. Focus on leaks that you can feel with your hand — those are the costliest.

Install window insulation film. Window insulation kits turn single-pane windows into near double-pane performance. Available for $30 or less per large window, these create an insulating air gap between plastic and glass. Nearly invisible when properly installed, you can remove them in the spring.

Deploy draft stoppers and weatherstripping. Air leaking under doors can account for loss of heat due to constant passive airflow. Removable door sweeps and draft stoppers cost $20 or less to stop this loss. Stick-on foam weatherstripping around doorframes also makes dramatic comfort improvements. Prioritize exterior doors for maximum benefit.

Seal electrical outlets. Install foam gaskets behind outlet and switch covers on exterior walls. Simply unscrew the cover, place the gasket, then replace the cover. No electrical work is required, and the results are immediately noticeable.

Use thermal curtains. Heavy, insulated curtains reduce window heat loss by 25%. Close them at sunset to trap heat and open during sunny winter days to let in free solar heat.

Weatherization projects requiring landlord approval or homeownership

Apply professional-grade caulk and sealant. Caulking gaps around window frames, door frames and penetrations (pipes, wires, vents) creates an air barrier that dramatically improves energy efficiency. Focus on any gap through which you can see daylight or feel air moving.

Install permanent weatherstripping systems. While removable foam strips work, metal or vinyl V-strip weatherstripping installed in window channels and door jambs provides superior protection.

Insulate your water heater and pipes. Water heater blankets can reduce heat loss from a tank. Pipe insulation prevents heat loss from hot water lines and — critically — prevents frozen pipes during power outages or extreme cold. Install foam pipe insulation on hot water pipes and any cold water pipes in unheated spaces.

Upgrade attic insulation to climate-appropriate levels. The effectiveness of insulation at resisting (i.e. slowing down) heat transfer is measured by “R Value.” For a cold climate like ours, the recommendation is to aim for R-49 to R-60 (and choose cellulose over fiberglass if you can). Check your attic insulation depth — if you can see the tops of floor joists, you need more insulation.

Air seal the attic floor before adding insulation. Air leakage through the attic floor (around recessed lights, plumbing stacks, chimneys and attic hatches) can negate much of your insulation’s effectiveness. These air leaks are important to block, but improper materials and techniques can do more harm than good, so this is one area where you’ll probably want to hire a professional. This often-skipped step is crucial for energy efficiency and moisture control. Gaps around chimney flashing, plumbing vent pipes and electrical wire penetrations are common culprits for air leakage.

Insulate and air seal your basement or crawl space. Uninsulated basements and crawl spaces waste enormous amounts of energy. Insulating basement walls to R-15 and sealing rim joists (the wood framing where your first floor meets the foundation walls) can reduce heating costs by up to 20%. For crawl spaces, seal all vents, insulate the walls to R-15 and install a continuous vapor barrier on the ground. This creates a conditioned space that protects pipes and HVAC equipment from freezing while improving comfort and efficiency in living spaces above.

Upgrade to storm windows or window attachments. Full window replacement is expensive, but exterior or interior storm windows provide most of the benefit at a small fraction of the cost. DIY interior storm window panels can be built more affordably using clear acrylic sheets and magnetic strips.

Your October weatherization action plan

Winter is indeed coming. But don’t panic — prepare. This October and November, commit to completing at least one weatherization improvement before the first freeze. If you’re renting, start with the no-permission-required quick wins that will pay dividends immediately. If you own your home, consider tackling one project and planning for advanced improvements next year.

Every improvement builds on the previous one. Together, these improvements create a home that protects you and your family when extreme weather strikes and power fails. Start finding those air leaks this weekend to work on sustainability you can feel!

Peggy Siegle and Fred Horch are principals of Sustainable Practice. To receive expert action guides to help your household and organizations become superbly sustainable, visit SustainablePractice.Life and subscribe for free to “One Step This Week.” Our new book, “Your Earth Share: Seven Pathways to Sustainable Living,” is also available for purchase on our website.