Replacing an individual window sash may be necessary to preserve your home’s energy efficiency or replace any broken glass panes in your existing windows. The cost of this home improvement task is fairly manageable, as is the associated labor. Read on below to learn about the steps you need to take toward any successful window replacement, as well as the associated costs of this project.

If you would prefer to explore window contractors instead of going for a DIY installation, then we recommend the following:

How to Replace a Window Sash

You’ll first have to do some prep work before removing any window parts. This will begin with taking full measurements of your window opening. Whether you have wood or vinyl windows, you’ll be better served taking precise measurements before beginning any work in this area.

Measure for a New Window Sash

You’ll use the measurements here to inform your purchase of a new sash or window component.

Measure Across

Measure from the inside of one window side jamb to the other. The side jamb begins outside the sash stops on each side. Do this at the top, mid-point, and bottom of your window frame. If any measurements differ, then use the smallest one to guide your purchase of a new top or bottom sash.

Take Vertical Measurements

Measure from the sill to the head jamb — or where your upper sash rests when the window is closed. Once again, take three measurements on the left, right, and center of the sill and head jamb. Use the shortest measurement to refer to when purchasing your sash kit.

Remove and Dispose of Old Sashes

First, you’ll need to begin the removal process for your old sashes. The first step will be to remove the sash stops on the sides of your windows. Since you’ll be re-using these, you should exercise caution during the removal.

  • Score the paint between the sash stop and jamb: Using a utility knife, mark the paint on the window frame where the sash stop meets the jamb.
  • Pry up the sash stops: Insert a putty knife into the gap and gradually pry up the sash stops. Apply even pressure to minimize the risk of breaking.
  • Place to the side: Once your sash stops have been removed, place them away from your workspace to ensure that they don’t break.

Sash Removal with Windows with a Balancing Weight

Sash weights are meant to work as a part of a pulley system to exactly mirror the weight of their accompanying sashes. This makes raising and lowering your windows fairly easy, even if they’ve been made from heavier components. If your window has balancing weights, there will be telltale ropes feeding from the window sashes into the jamb liners on either side.

Bottom Sash

Your first step will be to cut the rope that attaches your bottom sash to its weights. Your bottom sash should come out easily once you’ve removed the sash stops and detached the weights. Grip the top and tilt it downwards out of the window opening. Once it is flat and parallel to the ground, tilt your bottom sash to the side to lift the bottom pins out of the window, and remove the sash.

Top Sash

Next, you should remove the parting bead, which is detailed in the above diagram. Don’t worry about breaking this piece of wood, as most double-hung window sash kits will come with these.

Pull your top sash down to the middle of your frame and pull it away from the frame in the same fashion in which you removed your bottom sash. Once your top sash is clear, cut the ropes attaching the weights.

Weight Removal

Your window weights will have fallen into the bottom of their intended pocket in the jamb liner. Using a screwdriver, detach the weight coverings along this liner. Do the same with the weight pulleys. Remove your weights and accompanying rope from the jamb liner.

Sash Removal with Windows with a Spring Balance

This applies to more modern windows. Once your sash stops are safely out of the way, removal is fairly easy. Vinyl or modern sashes will come with sash locks, which are compression clips on the top of each sash. Pushing them inwards towards the center, pull each window sash half away from the frame from the top. Once your window sash is parallel to the floor, tilt to the right or left and lift the window pins away from the jamb liner.

Next, you’ll want to pry the jamb liner away from the window jamb itself. You can do this with your putty knife by prying against each side of the jamb liners on both the left and right side of your window frame.

A contractor from Fenster Components demonstrates this process well in this video:

You’ll notice that your jamb liners have gaps that the pivot pins on your window sashes fit into. Keep your fingers clear of these gaps at all times, as the “clutch” (where your windows rest) could snap upwards at any time. This could lead to injury if your fingers get caught.

If Necessary, Fix Window Frame

At this point, you should conduct a walkaround and inspection of your window. Fully clean any debris or dirt from the inner and outer frame so you can see any potential damage. If any of your frames are rotted away or damaged, then you should consult a local window contractor about fixing it.

Install Your New Jamb Liners

Once you’ve purchased a window sash kit that aligns with the measurements you took in the first step of this process, you’ll be able to continue with the installation of your new window.

Quick sash kits come in a range of different window styles and materials. Your choice will depend on a few factors, including warranty offerings, insulation requirements, durability preferences, and cost.

Installing a new jamb liner should be fairly easy. Jamb liners — when included in a window sash kit — should secure easily in your window jamb opening. Simply press the top of your jamb liner into the gap in your window jamb, and use your putty knife to crimp in the edges to fit.

This video from Kolbe Windows and Doors demonstrates how straightforward this step can be:

Install the Replacement Window Sashes

Once your jamb liners are in place, you should be able to install your top and bottom sashes quickly. Beginning with your top sash, line up the pivot pins on the bottom of the sash with the clutch within the jamb liner. Ensure that the two ends of the window are level before pushing the top half of the sash into the jamb liner.

Once both clips have been engaged on your new sash, test the window to ensure that the jamb liner/ sash assembly is in working order. Then, repeat this step for your lower sash and lock your window.

Replace Window Stops

Next, you should nail all window stops along the top and sides of your window opening back into place. This will make your window look finished and will provide additional security for your new window sash.

Where to Buy Replacement Window Sash Replacement Kits

You can purchase a new window sash replacement kit at nearly any big box hardware store. If your windows have odd measurements that aren’t readily available, then purchasing kits online through Amazon or a window provider’s website may be needed. Some of the top brands for such applications include Pella Windows, Andersen Windows, and Jeld-Wen.

How to Know if Your Sashes Need to be Replaced

Here are a few basic indicators that should let you know that at least one of your window sashes is in need of replacement:

  • Not easily operable: If your window sashes stick or take an inordinate amount of force to open, then it could be a sign that you need to install new window components.
  • Drafts: If you feel a draft when walking by your windows, then this is a clear indicator of low home energy efficiency. You may have to look into a full window replacement if this is the case.
  • Noise from outside: This typically goes hand in hand with poor insulation. A key function of quality windows is that they are able to keep most outside noise from entering your living space. Replacing such window sashes could make for a more peaceful home life overall.
  • Visible damage: Visible chips, holes, or rot should also be remedied as soon as they’re spotted. Since they can be a visible indicator of the three other conditions listed above, this is something you’ll want to fix for more than simply aesthetic reasons.

Fixing the Window Sash vs. Full Window Replacement

Even if you opt for DIY window replacement, installing new windows on your entire home can be a fairly costly project. You should replace your entire window if one or more of the following have occurred:

  • Your existing window sashes are immovable.
  • There is noticeable rot on the exterior of the frame.
  • There has been insect or pest damage done to your windows.
  • Siding or adjoining wall components are damaged.

If you’re interested in DIY window replacement, then consult our window installation guide to learn more.

Window Sash Replacement Cost

The costs below show average price points (without labor) for a few different makes window sashes. Typically, window contractor labor will cost between $35 and $50 per hour, which could equate to around $100 to $120 per window.

  • Single-hung: $200 – $500
  • Double-hung: $250 – $750

Vinyl windows are the most affordable option as a window replacement, starting at $90 to $100 per window, while wooden windows are the most costly option. Their costs begin at $250 to $300 per window and can range from $1,500 to $2,000.

Final Thoughts

Window sash replacement is an accessible project which most homeowners can safely attempt. Especially for first-floor window sash replacements on more modern windows, many DIYers with the right tools should feel secure in trying to complete this relatively simple home renovation. We at Today’s Homeowner will always recommend that you get at least one consultation from a licensed professional before you begin.

If you haven’t attempted any window repairs before, then it may be worth hearing a qualified second opinion to list any pitfalls you could run into. However, if you follow the steps outlined here, and purchase a quality replacement sash, then you should be well on your way to a successful window renovation.

Frequently Asked Questions

Can you replace just a window’s lower sash?

Yes. Many window sash kits have single upper and lower sashes, which make window installation fairly easy for many homeowners to tackle on their own.

What is the difference between a window sash and a window frame?

The window frame is the housing for the entire window assembly. Window sashes, on the other hand, are the individual sliding portions of a window, which contain the glass and insulation needed to shield your home from the elements.

Does a window sash include glass?

Yes. If you purchase a modern double-hung or single-hung window sash kit, it should come with glass, liner clips, brackets, and jamb liners as well. Depending on the sash kit, you may have to purchase some hardware. However, this will vary depending on the manufacturer.

What does a window sash do?

A window sash is half of a traditional residential window assembly. Window sashes slide within the window opening and include weather stripping for insulation purposes.

Editorial Contributors
Sean Donnelly

Sean Donnelly

Staff Writer

Sean Donnelly works to inform, engage, and motivate homeowners to take the reigns in making key decisions concerning homeownership and relocation. He is a content producer covering provider reviews, the homeownership and rental experience, real estate, and all things moving for Today’s Homeowner. Sean leverages his own experience within the moving industry to improve the consumer experience. He studied English literature and creative writing at the University of Massachusetts, Amherst.

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Lora Novak

Senior Editor

Lora Novak meticulously proofreads and edits all commercial content for Today’s Homeowner to guarantee that it contains the most up-to-date information. Lora brings over 12 years of writing, editing, and digital marketing expertise. She’s worked on thousands of articles related to heating, air conditioning, ventilation, roofing, plumbing, lawn/garden, pest control, insurance, and other general homeownership topics.

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