Renters: window film under $100 that comes off in spring

Put a shrink-film kit on the draftiest windows first. ENERGY STAR's plastic-over-windows project rates it easy, one day of work and under $100, says the film reduces drafts and condensation, and says that when winter is over the tape pulls off the trim without damaging the finish. Add weatherstrip where a sash moves, caulk where a gap does not, and curtains closed at night. It is a small buy a renter can make with scissors, a utility knife and a hair dryer; owners can use the same kit. The one condition: check your lease before anything that drills or sticks permanently.

A sheet of paper finds the leaky sash for free

Two free tests come before any purchase. The ENERGY STAR project page gives the paper test: close the window on a piece of paper, and if it moves back and forth easily, the window could be tighter, a fix the page assigns to thicker weatherstripping. The same page lists rattling windows, visible gaps around the trim and peeling paint around the frame as signs of air leaks. DOE's Energy Saver guide (2022) adds a smoke test: on a windy day, carefully hold a lit incense stick or a smoke pen next to the window, and if the smoke stream travels horizontally, you have found a leak. Check the sash, the frame and the trim. Note which gaps move when the window opens.

The curtains you already own are the third free change. DOE's 2022 guide says to close curtains and shades at night to protect against cold drafts, open them during the day to let in warming sunlight, and on summer days close draperies on windows that get direct sunlight. Keep them clear of radiators, baseboard heaters and warm-air registers, which the same guide says should not be blocked by drapes.

Seal each window, then cover it with film that comes off in spring

Match the material to the gap. Weatherstrip goes where parts move, the sash against the frame: DOE's 2022 guide says to weatherstrip doors and windows, and the paper test shows which sash needs it. Gaps that never move, between frame and trim, take caulk: ENERGY STAR's DIY sealing guide (2016) lists caulk for holes of 1/4 inch or less and spray foam for gaps from 1/4 inch to about 3 inches. A renter asks the landlord before caulking the trim. A gap wider than 1/4 inch goes on the landlord's list, because the guide's fix for it is foam.

Then the film. The ENERGY STAR project page lists the kit (clear plastic film with double-sided or magnetic tape), scissors, a utility knife, a hair dryer, a tape measure, cotton balls and rubbing alcohol. Buy a kit that fits the window's width, size the film with a few inches spare on each side, clean the frame, apply the tape and then the film, and shrink it tight with the hair dryer. Run it over the woodwork: the page says the film can then also eliminate air leaks around the window, and the extra layer of plastic adds a layer of insulating air that reduces heat loss through the window. When winter is over, take the plastic down and pull the tape off the trim.

For a window that still feels drafty after that, DOE's 2022 guide suggests tight-fitting insulating shades, such as honeycombed cellular shades.

What the windows are worth, and what the landlord handles

Windows are the reachable job, not the biggest one. The ENERGY STAR project page says window projects may have less impact on energy use than those in the attic and basement, and ENERGY STAR's DIY guide (2016) says the most significant air leaks in most homes are hidden there.

Example, with published figures and one assumption. EIA's RECS 2020 table CE3.6 puts a rented apartment's average 2020 spending at $248 for space heating and $176 for air conditioning, each per household using it: $424 for both. DOE's Home Upgrades page, last updated June 2026, says heat gain and heat loss through windows are responsible for 25% to 30% of residential heating and cooling energy use. Assume the windows take the same share of the dollars, the example's own assumption: $424 × 0.25 = $106 and $424 × 0.30 = $127.20, so about $106 to $127 of that apartment's 2020 heating and cooling bill moved through its windows. ENERGY STAR puts the film kit under $100. That range is what the windows cost, not what film saves: no linked source puts a figure on the film's saving.

Hand the bigger jobs to the landlord. DOE's 2022 guide says low-e exterior or interior storm windows can save 10% to 30% on heating and cooling costs, depending on the type of window already installed; ask the landlord about them, and about sealing the attic and basement, the work laid out in seal air leaks before you add insulation. On DOE's Weatherization Assistance Program apply page, accessed October 2026, a household at or below 200% of the poverty income guidelines or receiving Supplemental Security Income is eligible, renters can apply, and the local provider works with you and the landlord to get permission before work begins; free weatherization covers how to apply.

If the apartment has a gas furnace, water heater or dryer, ENERGY STAR's DIY guide (2016) warns that a tighter home can let carbon monoxide build up when those appliances do not vent properly, and says to have a heating and cooling technician check their venting. Ask the landlord to send a licensed HVAC contractor; sealing a home with gas appliances covers the alarms and the yearly check.