Who Replaces Window Sills?

This article was created using automation technology and thoroughly fact-checked and edited by HomeAdvisor Editor Ryan Noonan.

If you are asking who replaces window sills, hire a window repair company or an experienced handyperson. Window repair companies with licensed contractors ensure correct installation and water- and air-tight seals. Choose a pro when your experience is limited or your windows are not standard.

These companies can replace a full frame or just the sill, as needed. Hiring a pro offers confidence the fit, angle, and sealing are correct for long-term performance.

Benefits of Hiring a Window Repair Company for Replacing Window Sills

A window repair company handles the full scope: assessing the frame, fabricating the sill, and sealing against air and moisture. Their tools and experience help prevent repeat issues and reduce the risk of needing a full frame replacement later. For many homes, the peace of mind is worth the extra labor cost.

• Familiarity with sill and frame construction across materials and capping

• Tools to precisely fabricate, fit, and secure new sills

• Correct slope and sealing to direct water away

• Ability to spot and repair surrounding damage before it spreads

• Consistent, water- and air-tight installation quality

• Confidence that the work is done right the first time

• Capacity to handle standard and complex window assemblies

• Safer management of ladder work on upper floors

Can I Hire a Handyperson for Replacing Window Sills?

An experienced handyperson can replace standard-size window sills and is a good fit when the job is straightforward. Confirm they understand all window components, not just trim, and ask for examples of past sill and frame work. For non-standard windows or complex frames, hire a window repair company to ensure proper fit and sealing. Prioritize experience over price to avoid improper angles or gaps. Many carpenters also have the skills for standard-size windows; confirm full window component experience. If you’re not sure where to start, you might want to consider a handyman near you to ensure the job is done correctly and efficiently.

How Do Pros Replace Window Sills?

Pros follow a clear, careful process to protect the window and surrounding materials.

1. Examine frame construction and note sill material; identify capping or cladding if wood

2. Uncover the sill and frame to locate damaged areas

3. Remove damaged components that require replacement

4. Fabricate a new sill to fit the existing frame

5. Repair areas around the sill as needed and seal the opening

6. Install the new sill, ensuring correct angle and tight sealing

7. Complete final sealing and checks so the sill lasts for several years

How Much Does Replacing a Window Sill Cost?

Most professional window sill replacements cost between $150 and $700, depending on window size and material. Aluminum sills are the least expensive, while wood is the most expensive. A wooden bay window sill replacement can reach $1,100. When damage extends beyond the sill, replacing the entire window frame averages $380. DIY or minor repairs run about $200 to $300, but errors with angle or sealing often lead to more damage and added expense.