Renovation guides

Replace windows: what a pro does and what you can do

Contractor work. Your part is to count and measure, flag the bedrooms and the safety-glass spots, get bids that name the energy numbers and the flashing, and check the result.

Difficulty 5 of 5 · licensed pro

Photo of your room, the look you pick, then this guide with the materials counted for your room.

Step by step

1. Step 1 of 9

   Accept that this one is not yours to do

   

   Removing windows opens the wall, and the flashing, egress, safety glass and energy code make this licensed, permitted work. Your part is to count, measure, hire well and check the result. Read the stop-gate and confirm you understand it.

   Before you go further

   • You will not remove a window or pry at the old frames yourself
   • You understand this is licensed work and usually needs a permit
   • You have a place to keep bids, the permit, and the manuals together

2. Step 2 of 9

   Count and photograph every window

   

   Walk around the house and number every window on a sketch. Photograph each one from outside and inside, including the sill, the frame corners and any stains or rot below it.

3. Step 3 of 9

   Measure each opening for the bids

   

   Measure the width at the top, middle and bottom, and the height at the left, middle and right, inside the frame. Note how each one opens. These numbers are for comparing bids — the installer measures again before ordering.

4. Step 4 of 9

   Flag the bedrooms and the safety-glass spots

   

   Mark every bedroom window on your sketch: it must stay big enough to escape through, and the contractor confirms each one. Mark windows near a door, a tub or shower, stairs, or close to the floor — these often need tempered glass.

5. Step 5 of 9

   Ask about retrofit or full-frame

   

   A retrofit insert goes into the old frame and disturbs less stucco or siding. A full-frame replacement fixes rot and rebuilds the flashing, but opens the wall. Ask each bidder which they recommend for each window and why.

6. Step 6 of 9

   Check for lead paint in an older home

   

   If the house was built before 1978, assume the old frames and sills carry lead paint unless a certified inspector says otherwise. Hire an EPA RRP lead-safe certified firm, and plan to keep children and pregnant people away while the old windows come out.

7. Step 7 of 9

   Get three bids that name every part

   

   Each bid should name the window model, the U-factor and SHGC that meet your energy code, the flashing method, the trim and stucco or siding patch, lead-safe work if needed, the permit, haul-away and the warranty. Check each contractor's license with your state's contractor license board (CSLB in California) and ask for proof of insurance.

8. Step 8 of 9

   Clear the way for install day

   

   Take down blinds and curtains, move furniture away from every window, and clear a path outside along the walls. Photograph the walls around each window before the crew starts.

9. Step 9 of 9

   Check every window and close the job

   

   Open, close and lock each window. Look for continuous sealant and flashing outside, and patched trim inside. Leave the labels on until the inspector has seen them, then keep them in the job folder.

   Before the final payment

   • License and insurance checked before signing
   • Every window opens, closes and locks
   • Bedroom windows were confirmed for egress
   • The permit is signed off
   • Labels, warranty and invoice are in the job folder

Draft guide written from standard practice, not yet reviewed by a licensed pro. Follow product labels where they differ.

Español