Window replacement cost depends on how many openings there are and how big they are, the frame and glass chosen, whether the old frame stays or comes out, what the crew finds behind the trim, and the work around each window, from flashing and permits to disposal. Ask each contractor which of these a bid’s total includes.
What are the line items in a window replacement bid?
A window replacement bid can cover each opening, the window itself (size, frame, glass and operating style), the installation method, trim and flashing, repair of damaged wood, lead-safe work in older homes, permits, removal and disposal, and the contractor’s overhead and profit. A bid may list these separately or give one total, so ask which lines the total includes.
What can move each line item?
Each line has its own drivers. The table gives each line in plain words, what can change it, and a question to put to every contractor. A blank answer is information: it means the bid is silent on that line, and you can ask before you compare the totals.
| Line item | What it is and what can move it | What to ask |
|---|---|---|
| Number and size of openings | Each opening is one unit to build and install. More openings add units, and larger openings take larger frames and more glass. | How many openings are in the bid, and what size is each? |
| Frame material | ENERGY STAR says fiberglass frames are “strong, durable, low maintenance, and provide good insulation,” vinyl frames are “low maintenance and provide good thermal insulation,” aluminum frame design includes “thermal breaks to reduce conductive heat loss through the metal,” and some wood windows “are clad (or covered) with aluminum or vinyl to reduce maintenance.” | Which frame material is on the bid, and is a wood frame clad outside? |
| Glass package | A U.S. Department of Energy resource describes two or three panes of glass, “an odorless, colorless, nontoxic inert gas such as argon or krypton” between them, and “low-emissivity (low-e) coatings” on the glass. | How many panes, which coating and which gas fill? |
| Energy ratings: U-factor and SHGC | The same resource says “The lower the U-factor, the better the window insulates.” It says “The lower the SHGC, the less solar heat the window transmits.” It says ENERGY STAR uses “a climate zone map with four zones” to set its U-factor and SHGC criteria. | What are the U-factor and SHGC on each label, and which climate zone is my home in? |
| Full-frame or insert | The Department of Energy’s checklist says homeowners “must decide between a full-frame window replacement that includes sealing the air gap and adding flashing, or the much more common practice of minimizing replacement window cost by installing within the existing frame without sealing the air gap and adding flashing.” | Is each window an insert or a full-frame replacement, and what does that include? |
| Operating style | A National Fenestration Rating Council consumer guide calls a single-hung window “a simpler and less-expensive version of the double-hung” and says bay and bow windows “can also be more expensive and less efficient.” | What style is each opening, and which sashes open? |
| Grids and hardware | Grid patterns, locks, handles, screens and finishes are choices. A bid may price them on their own lines or fold them into one unit price. | Which grids, hardware, screens and colors are included? |
| Exterior trim, capping and flashing | The checklist says “Exterior cladding or trim shall be removed as required to install exterior head, jamb, and sill flashing.” | Which trim is replaced, wrapped or capped, in what material, and who finishes it? |
| Rot and hidden damage | The replacement guide says “If damage to existing elements is noted, the materials should be removed and replaced as part of the retrofit,” and that water problems “are often concealed within wall cavities with no outward signs.” Damage may show only after the old window is out. | Is repair priced per item, carried as an allowance, or left out? |
| Lead-safe work before 1978 | EPA says its rule covers work that disturbs paint in housing built before 1978, and that “Window replacement and demolition of painted surfaces are always covered regardless of square footage.” EPA says the rule includes work practice requirements, so a bid for an older home may carry a line for lead-safe work. | Was my home built before 1978? If so, how will lead-safe work be handled, and is it in the bid? |
| Egress, safety glass and permits | The checklist says egress windows and safety glass “shall be specified in accordance with” the building codes. Ask whether any opening falls under those requirements, because they decide what can be specified there. Whether a permit is needed, and its fee, depends on where the home is. Your city or county building department can tell you what applies. | Do any windows fall under egress or safety glass rules, and who applies for the permit? |
| Removal, disposal and access | The replacement guide says to “Completely remove and dispose of or recycle the window sashes and frame,” and that “scaffolding, lifts, ladders, or other means to access work areas may be needed.” | Who removes the old windows, and is equipment for upper floors in the bid? |
| Labor, overhead and profit | Labor is the crew’s time for everything above. Overhead is the cost of running the contracting business that is not one job’s materials or crew: insurance, trucks and fuel, an office, marketing and sales commissions. Profit is what the contractor keeps. A bid’s total includes all three, whether or not it shows them. | Does the bid show overhead and profit, or fold them into the total? |
How do I read a window bid line by line?
Start with the count. A bid should list one line for each opening, and its unit count should match the openings you counted. Then read what “installed” covers in writing. Treat anything not written on the bid as not in the price until the contractor confirms it in writing.
- Unit count. Count your openings, then count the units on the bid. A mismatch means a window was left out or added.
- One line per opening. Each line should give the location, size, frame, glass, grid and operating style.
- What “installed” includes. Ask in writing whether it covers removal and disposal, flashing, trim, caulk, interior finish and cleanup.
- Allowances and exclusions. Look for “allowance,” “if needed” and “not included,” especially around rot repair, lead-safe work and permits.
Why can two window bids for the same house have different totals?
Two window bids can total different amounts because they price different jobs. One may count every opening where another leaves one out, replace the whole frame where another installs inserts, carry a rot allowance where another carries none, or quote a different frame or glass package. Match the lines first, then compare the totals.
Our guide to How to Compare Window Replacement Bids turns these lines into a table you can fill in for each bid. The same method works for other trades: What Goes Into the Cost of a Roof Replacement? and What Affects the Cost of Siding Replacement?.
How does getting bids on one written scope help me compare?
When every contractor prices the same written scope, the openings, sizes, frames, glass and extras are the same on every bid, so the differences you see are in price and terms. On Otter Quotes, contractors who receive the scope can submit bids, and you compare them online.
Storm damage to windows may be part of an insurance claim. Your policy and your insurer answer coverage questions. Otter Quotes does not work with insurance companies.
What should I ask every window contractor?
Copy this list and put the same questions to every contractor.
- How many openings, and what size is each?
- Which frame, glass package, grids and operating style are written for each opening?
- What are the U-factor and SHGC on each label?
- Is each window an insert or a full-frame replacement?
- Which trim, flashing and finish work is included, and who does it?
- How are rot and hidden damage handled, and how is lead-safe work handled if my home was built before 1978?
- Who applies for the permit, and who removes the old windows?
Where Otter Quotes fits
Otter Quotes creates a written scope of work for your project and sends it to multiple contractors. Every bid is on the same scope and the same measurements, so you are comparing the same job. You compare the bids online, next to reviews and licensing information, without a salesperson visiting your home.
Because contractors know they are competing, they are more likely to include better materials and warranties. Otter Quotes is not a contractor, does not sell upgrades and does not work with your insurance company. Contractors pay Otter Quotes a fee on the accepted bid.
Frequently asked questions
What affects the cost of window replacement?
A window replacement price covers the windows, which depend on the number and size of openings, the frame, the glass and the operating style, plus installation, trim and flashing, any wood repair, lead-safe work in older homes, permits, removal and disposal, and the contractor’s overhead and profit. Each contractor’s bid shows which of these it includes.
Is a full-frame replacement different from an insert?
Yes. A U.S. Department of Energy checklist describes a full-frame replacement that includes “sealing the air gap and adding flashing” and the “much more common practice” of installing within the existing frame. They are different jobs with different work, so ask each contractor which one the bid assumes and what it includes.
Does window replacement need lead-safe work?
In a home built before 1978 it can. EPA’s page on its renovation rule says “Window replacement and demolition of painted surfaces are always covered regardless of square footage.” Ask each contractor how the crew will handle lead-safe work in your home and whether it is in the bid.
What do U-factor and SHGC mean on a window label?
A U.S. Department of Energy resource says U-factor measures “how well the window insulates” and that “The lower the U-factor, the better the window insulates.” It says “The lower the SHGC, the less solar heat the window transmits.” Ask for both numbers on every window in every bid.
Why does this page not list a price per window?
A price depends on your house, the products chosen and the contractors bidding, none of which a general page can see. This page names the line items and what moves them. A written bid for your own house is the number to compare.
Sources
- ENERGY STAR, U.S. Environmental Protection Agency and U.S. Department of Energy, What makes it ENERGY STAR? (windows, doors and skylights).
- Building America Solution Center, Pacific Northwest National Laboratory, U.S. Department of Energy, High-Performance (ENERGY STAR) Windows.
- Building America Solution Center, Pacific Northwest National Laboratory, U.S. Department of Energy, Window Replacement (Home Improvement Expert checklist).
- Building America Solution Center, Pacific Northwest National Laboratory, U.S. Department of Energy, Complete Window and Frame Replacement.
- U.S. Environmental Protection Agency, Renovation, Repair and Painting Program: Contractors.
- National Fenestration Rating Council, Consumer Guide to Windows, Window styles: you’ve got options.