How to Estimate Window Costs


Many older homes have old windows that are, inefficient, damaged or unsightly which may need to be repaired or replaced on your rehab projects. As a house flipper, you will need to be able inspect the windows and determine whether the windows need to be repaired or replaced and estimate an approximate budget.

Basics Of Estimating Window Costs

Windows are simply measured and estimated based upon the count, so to estimate your windows you simply need to count the # of windows you need to replace in the property and multiply the count by an average cost per window.

Installation Costs

  • Remove existing windows ($25 - $50 each)
  • Vinyl Windows , single, average size ($175 - $300 each)
  • Vinyl Windows , double hung,  average size ($225 - $350 each)
  • Wood Windows, average size ($300 - $500 each)
  • Windows, large/custom ($500 - $1k each)
  • Basement windows, operable ($150 - $300 each)
  • Skylights, fixed ($300 - $750 each)
  • Skylights, operable ($500 - $1k each)
  • Aluminum glazing (commercial storefront) ($30 - $50 per square feet)

Installation Timeline

On a 1,500sf rehab project you will likely have between 10 to 15 windows that need to be replaced. Replacing each window typically takes between 1 to 2 hours, so a window crew can usually complete an entire home window installation in 1 to 2 days.

Other Costs

  1. Repair broken window panes ($150 - $300 each)
  2. Exterior/interior window trim ($75 - $125 each)

Price Considerations

#1 Type of Window Material

The most obvious factor that influences window pricing is the type of window material being installed.  Vinyl windows are the cheapest ($100 to $300 material), whereas custom wood windows can be $300 to $1,000 each.

#2 Window Operation

Fixed windows are cheaper than operable windows that open and close.

#3 Number of Windows

In construction, there is a term called economies-of-scale.  The larger the project, the more efficient the contractor can be installing the windows.  The unit price (price per window) to install just 1 window would be way higher than the price to install 10 windows.  Ex:  A project that has one window may cost $500 ($500/1 = $500 per window), whereas a project with 10 windows may cost $3,000 ($3,000/10 = $300 per window).

#4 Size of Windows

Standard window sizes (~2 to 3ft wide x 4 to 5ft tall) are cheaper than large windows (3ft+ wider).  Custom window sizes will also be a premium to in-stock windows.

#5 Window Rough Opening Modifications

If you are changing the size of the window rough-opening this will require additional work for framing, siding, & painting.

Writing A Scope Of Work & Getting Bids

Window contractors will generally provide an all inclusive bid to 'furnish and install' all labor and window materials on the project. Window procurement is a time-consuming process that involves field measuring all of the window rough openings and purchasing the correct sized windows.  You do not want the risk or responsibility of measuring your own windows, so always rely on your Window Contractor to furnish and install all window materials on your rehab projects.

Here is an example of how to write a Scope of Work that insures your Window Contractor provides an all-inclusive bid.

Example Scope Of Work

All Window work (including window materials) are to be Contractor Purchased, Contractor Installed.

  1. Contractor to field verify and measure all window openings.
  2. Furnish and install new windows.
  3. Window Specification: Input Window Specification. Alternate materials and manufacturers that provide savings will be considered, but must be approved.
  4. Remove existing windows to be replaced with new.
  5. Furnish and install caulking, flashing, trim boards around windows to provide water tight installation.