How to Seal Windows and Doors to Save on Energy Bills

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Did you know that leaky windows and doors can account for up to 30% of your home’s heating and cooling loss? That’s money slipping right through the cracks—every single month.

The good news? Sealing your home isn’t just affordable—it’s also one of the most impactful energy-saving upgrades you can do yourself. A few well-placed seals can significantly reduce your monthly utility bills, improve indoor comfort, and extend the life of your HVAC system.

This guide breaks down the steps for sealing windows and doors effectively, what supplies you’ll need, and when it’s time to call in a Puls pro for expert help.


Why Sealing Matters More Than You Think

Drafty doors and windows don’t just make your home feel chilly in the winter and stuffy in the summer. They create a hidden energy drain that causes your HVAC system to work overtime—leading to:

  • ❄️ Higher heating and cooling bills

  • 💨 Unwanted outdoor air infiltration

  • 🦠 Poor indoor air quality

  • 🛠️ More wear and tear on your HVAC system

  • 🦟 Increased pest and allergen exposure

According to the U.S. Department of Energy, sealing air leaks can reduce heating and cooling costs by 10–20% on average. In homes with aging windows and doors, the impact can be even greater.


How to Seal Drafty Windows

Windows are one of the biggest culprits when it comes to energy loss. Here’s how to spot and fix common window leaks.

Step 1: Find the Drafts

Use a lit incense stick or a candle on a windy day. Slowly move it around the edges of your window frame. If the smoke flickers or pulls in one direction, you’ve found a leak.

You can also use:

  • A handheld thermal leak detector

  • Or your hand on cold days to feel for air movement

Step 2: Apply Caulk to Stationary Gaps

For cracks where the window frame meets the wall (especially outside), use silicone-based weatherproof caulk to seal the gaps.

  • Scrape away any old, cracked caulk with a utility knife or putty tool

  • Apply a steady bead of new caulk, smoothing it with a damp finger or tool

  • Use paintable, clear caulk for a neater finish

Step 3: Add Weatherstripping for Movable Parts

Window sashes (parts that slide or swing open) often leak where they meet the frame. Apply adhesive-backed foam, rubber, or vinyl weatherstripping to fill the gaps.

Make sure surfaces are clean and dry before applying for best adhesion.

Optional: Install Window Insulation Film

In colder months, clear plastic window insulation kits can add an extra layer of protection. They’re especially effective for single-pane windows.

Supplies Needed:

  • Caulking gun and silicone caulk

  • Weatherstripping kit

  • Utility knife

  • Rubbing alcohol or cleaner

  • Tape measure


How to Seal Doors

Doors see frequent use and movement, which means their seals wear down faster than you might expect.

Step 1: Inspect for Air Leaks

  • Close the door and look for visible light around the edges.

  • Slide your hand along the frame to feel for cold air or drafts.

  • Look underneath the door—this is a common weak spot.

Step 2: Replace Weatherstripping

Most exterior doors have a built-in seal that can be easily replaced.

  • Peel off the old weatherstripping

  • Clean the area

  • Press the new material into place, ensuring a snug fit

Choose the right profile (V-strip, foam, rubber) for your specific door type.

Step 3: Install a Door Sweep

A door sweep covers the gap between the bottom of the door and the threshold.

  • Choose a sweep made from rubber or brush-style material

  • Screw or slide it into place along the bottom interior edge

  • Make sure it makes light contact with the floor but doesn’t drag

Bonus Fixes:

  • Use door draft stoppers or snakes for temporary insulation

  • Add an insulated storm door for additional protection

Supplies Needed:

  • Door sweep

  • Weatherstripping

  • Scissors or utility knife

  • Screwdriver or drill


When to Call a Pro

While many sealing tasks are beginner-friendly, there are some issues that require professional attention.

Call Puls if you notice:

  • 🚪 Doors that won’t close or latch properly

  • 🪟 Windows that rattle or won’t stay shut

  • 💧 Water stains or signs of moisture around sills or frames

  • 🛠️ Drafts that persist even after DIY sealing

  • 🧱 Evidence of structural shifting around the door or window frame

A Puls handyman can help assess the damage, make structural repairs, replace compromised materials, and apply commercial-grade weatherproofing products that last longer and seal better.


Pro Tip: Seal Before Winter AND Summer

Most people only think about sealing drafts in the winter—but it's just as important during the summer.

In hot climates, sealing up air leaks:

  • Keeps cool air from escaping

  • Prevents hot, humid outdoor air from getting in

  • Reduces HVAC cycling, which means fewer breakdowns

Doing a full seal check in both spring and fall ensures year-round energy savings.


Advanced Weatherproofing Options

For long-term protection, especially in older homes, consider these pro-level upgrades:

1. Insulated Window Panels

Temporary storm window kits or permanent inserts can increase efficiency without replacing your windows entirely.

2. Foam Spray Sealant

Expanding foam sealants fill large gaps around pipe entries, basement windows, or irregular surfaces.

3. Threshold Replacement

Old door thresholds can wear down over time. Installing a new one improves both the seal and the stability of your entryway.

4. Exterior Caulking and Sealing

A pro can walk your home’s perimeter and seal foundation cracks, gaps around outdoor faucets, attic vents, and more.


More Tips to Maximize Energy Efficiency

Sealing doors and windows is step one — but pair it with these for even better results:

  • 💡 Use thermal curtains or cellular blinds to reduce heat loss through windows

  • 🚪 Close off unused rooms to contain airflow

  • 🔌 Install smart thermostats that adjust temperature based on usage patterns

  • 🪟 Tint windows or apply UV-blocking film for additional solar protection

  • 🧼 Clean HVAC vents and replace filters regularly to maintain system efficiency


What About Window and Door Replacement?

If your windows or doors are more than 20 years old, damaged, or permanently warped, sealing alone might not cut it.

While full replacement is a bigger investment, it can:

  • Increase your home’s value

  • Significantly cut down on energy loss

  • Improve comfort and noise reduction

  • Make your home more secure

Talk to a Puls expert for an honest assessment of whether repair or replacement makes more sense for your situation.


✅ Book Handyman Services with Puls Today!

Drafts may be invisible, but their impact on your energy bills is very real.

Whether you need help sealing tricky gaps, replacing worn-out weatherstripping, repairing old door frames, or upgrading insulation, Puls is here to help.

🛠️ Book a Puls handyman today and enjoy:

  • Fast, affordable repairs

  • Expert weatherproofing

  • Reliable help with windows, doors, and more

  • Peace of mind—every season

📅 Schedule your appointment now and take the first step toward a cozier, more efficient home.

Puls
Puls offers over 30 on-demand home services nationwide, including TV mounting, plumbing, and smart home installations, with same-day availability and seamless booking. We also offer home warranties and property management solutions, making us a one-stop-shop for all home maintenance and repair needs. Visit our blog for more tips and advice.
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