Cost to Install an Octagon Window – 2021

| Last Updated: August 24, 2021

National Average Improvement and Repair Cost







$ 486

$ 175

Would you do this project? According to our survey, 78% of respondents preferred DIY compared to hiring a pro.

The average price to Install an Octagon Window noted above is cost data to compare a contractor’s estimate with doing it yourself.

How much is an octagon window? The contractor cost to install an octagon window is $486 vs. doing it yourself for $175 and saving 64 percent. 

The small 8-sided window with a strong resemblance to a stop sign serves a purpose often needed in today’s home. It’s ideal in a tight spot where a ray of daylight is needed to brighten a dark space. It is frequently used to add light in an entry foyer, at the top of a staircase landing or in a small bathroom, all places where it can add architectural interest to an otherwise blank wall. When ventilation is needed, an opening unit is a good choice.

Octagon windows are sold at window, lumber, and home centers as fixed and opening units made of wood, aluminum and vinyl. A carpenter will charge $486 to install a 24-inch opening vinyl-clad unit with insulated glass, which includes the labor and the window. A handy homeowner with carpentry tools and experience can buy the unit for $175 and install it, pocketing a 64 percent saving.

Don’t tackle this job unless you are competent, because it requires cutting a hole in the siding of the house. And don’t even think about doing it yourself if the house is made of brick or stone; definitely hire a contractor who has the tools and experience.

Plan to position the unit between wall studs; you’ll need an electronic stud finder to locate them. The job involves cutting a rough opening, positioning and adjusting the unit with wooden shims so that it’s level, and then fastening the unit to the studs with screws and caulking around the interior trim and siding.

SFGATE has this advice about How to Install an Octagonal Windows.

Wrapping up, given the average cost to install an octagon window you can compare the price of a contractor’s bid with doing it yourself. 

Welcome! We hope you’ll find the job costs of home improvement projects useful when you’re deciding whether to do a job yourself vs. hire a contractor. We’re the authors of 20 home improvement books, most notably Home Improvement for Dummies©, Bathroom Remodeling for Dummies©, Carpentry for Dummies©, Plumbing for Dummies©, and Painting and Wallpapering for Dummies©. Our most recent book Fix It and Flip It is in its second edition. We’ve appeared as home improvement experts on television programs such as CNN, Dateline, the Today Show, HGTV and many others.