What are the most effective low-cost methods to reduce drafts around windows and doors?

Quick answer

The most effective low-cost ways to cut drafts around windows and doors are: add weatherstripping (foam, V-strip, or magnetic), install a door sweep, seal gaps and cracks with caulk or rope caulk, use interior window shrink film in winter, and adjust or repair thresholds and latches. Together, these fixes usually cost under $20–$60 per opening and can be done in an afternoon with basic tools.

Find where the drafts are

Before you fix, locate the leaks so you spend time and money where it matters.
- Visual checks: look for daylight around door edges and window sashes.
- Paper test (doors): close the door on a strip of paper; if it slides out easily, you need weatherstripping.
- Smoke/incense test: on a windy day, move a smoking incense stick along trim and seals; smoke will waver toward leaks.
- Tech option: a smartphone thermal camera or IR thermometer can highlight cold spots.

Low-cost fixes that work

Doors

• Adhesive foam or V-strip weatherstripping on the jambs and head ($5–$20 per door).
• Door sweep to seal the bottom gap; use a rubber fin for smooth floors or a brush sweep for uneven floors ($10–$25).
• Adjustable threshold (if present) or add a new one; raise just enough to kiss the sweep ($15–$40).
• Latch/hinge adjustment: snug hinges and adjust the strike plate so the door pulls tight to the weatherstrip (free if you have a screwdriver).

Windows (double-hung, casement, and sliders)

• V-strip (spring bronze or vinyl) along sides and meeting rails to seal moving joints ($8–$20 per window).
• Rope caulk pressed into small, removable gaps around sashes (good for renters) ($5–$10).
• Interior shrink film kit for winter; creates an airtight layer over the whole sash ($10–$20 per window).
• Caulk trim-to-wall gaps with paintable acrylic latex inside; use silicone or elastomeric outside ($4–$8 per tube).
• Foam backer rod + caulk for wider cracks around casing.

Bonus quick wins

• Outlet/switch gaskets on exterior walls ($3–$6 for a pack).
• Draft stoppers at door bottoms for temporary use ($10–$20).
• Thermal curtains to cut night-time heat loss (varies, low effort).

Tools and materials

• Weatherstripping (adhesive foam, V-strip, or spring bronze)
• Door sweep (rubber or brush), screws included
• Caulk (interior: acrylic latex/paintable; exterior: 100% silicone or elastomeric)
• Rope caulk, backer rod
• Shrink film kit, hair dryer
• Tape measure, scissors/utility knife
• Screwdriver/drill, caulk gun, putty knife
• Cleaning supplies: mild detergent, rag, isopropyl alcohol
• Optional: pry bar, miter shears/tin snips (for sweep), IR thermometer
• PPE: safety glasses, gloves; respirator if using solvent-based products

Step-by-step: common fixes

1) Weatherstrip a door (30–60 minutes)

1. Clean the door stop and jambs; let dry.
2. Measure and cut foam or V-strip to length. Dry fit.
3. Peel-and-stick foam so the door compresses it slightly when closed; avoid over-compression.
4. Install a door sweep: mark height so the seal just brushes the floor/threshold, predrill, and screw in place. Test and tweak.
5. Adjust strike plate so the latch pulls the door snug.

2) Seal window drafts (20–45 minutes each)

1. Clean sash tracks and the meeting rails.
2. Apply V-strip along the sides (jambs) where the sash slides, and at the meeting rail if accessible.
3. Press rope caulk into hairline gaps around the sash for a reversible seal.
4. For seasonal sealing, install interior shrink film: stick tape to clean trim, apply film, then gently heat to tighten.

3) Caulk trim-to-wall gaps (per room, 1–2 hours)

1. Vacuum dust from the joint; wipe with alcohol for adhesion.
2. For gaps larger than about 1/4", insert backer rod.
3. Cut caulk tip to the right bead size; apply a steady bead.
4. Tool with a damp finger or caulk tool. Allow cure per label before painting.

Useful specs
- Door sweep: just touching floor/threshold; no more than light drag
- Foam weatherstrip compression: ~25–50%
- Caulk joint: width > depth; target ~1/4" bead
- Backer rod: choose 25–50% larger than joint width

Safety and best practices

• Work in a well-ventilated area, especially with silicone or solvent-based products.
• Cut away from your body with utility knives; wear eye protection when drilling or cutting metal sweeps.
• Older homes (pre-1978): be cautious scraping paint due to potential lead; avoid sanding without proper containment.
• Don’t use expanding foam in the operable sash area; if foaming around frames, use low-expansion “window & door” foam to prevent bowing.
• Exterior sealing: leave weep holes and drainage paths open.

Cost and time expectations

• Door kit (foam + sweep): $15–$40; 45–60 minutes.
• Window V-strip + film: $18–$35; 20–45 minutes.
• Caulk + backer rod for a room’s worth of trim: $10–$25; 1–2 hours.

Tips for better results

• Clean and dry surfaces thoroughly; alcohol wipe improves tape adhesion.
• Warm adhesive-backed products indoors before installation for better stick.
• Color-match caulk where visible; use paintable caulk on interior trim.
• On metal or fiberglass doors, magnetic weatherstrip seals very well.
• If floors are uneven, choose a brush sweep rather than a solid rubber fin.

Common mistakes to avoid

• Using too-thin or too-thick foam: too thin won’t seal; too thick prevents closing.
• Over-tightening a sweep so the door drags or won’t latch.
• Caulking moving joints with non-flexible filler; use elastomeric or silicone where movement occurs.
• Sealing exterior windows shut unintentionally; keep egress pathways operable.
• Applying caulk or film to dirty, cold, or wet surfaces—adhesion will fail.

When to call a pro

• You see rot, sagging headers, or out-of-square frames causing binding.
• Persistent water intrusion around frames or masonry cracks.
• Fogged double-pane glass or failed window balances/springs.
• You’re considering full replacement for very old, inefficient units.

Target the worst leaks first—typically door bottoms, door latch sides, and window meeting rails. A few thoughtfully chosen materials and an unhurried install will make a noticeable difference in comfort and energy use without spending much.