How To Install & Replace Your Windows

Installing new windows can refresh the look of your home, improve energy efficiency, and add value to your property. But before getting started, you'll need to decide whether DIY or professional installation is the best route for your project. This guide covers everything you need to know, from costs to process to tips for success.

Estimated Time Per Window	Estimated Cost Per Window	Recommended Assistance	Skill Level
3 to 7 hours	$300 to $800	One helper	Intermediate

Please note that the above time estimate assumes that no structural alterations to exterior siding or frame have to be conducted. The estimated costs include the cost of a new window, as well as associated materials, but can be higher, depending on the kind of window you install.

DIY vs Professional Window Installation

DIY window installation has the benefit of significant labor cost savings, often 50% or more compared to hiring a pro. But it requires intermediate carpentry skills along with plenty of time and patience. Professional installation ensures quality workmanship and efficiency.

Consider the following factors when deciding between DIY vs hiring a contractor:

Number of windows: For more than 5 windows, the economies of scale often make hiring a pro worthwhile
Accessibility: Second story and difficult to access windows are safer left to professionals
Window types: Unique sizes, custom windows, and specialty products like bay or curved windows require expert installers
Time constraints: DIY takes days per window; pros can replace dozens of windows in a single day
Skill level: If you don't have experience with window installation, DIY has a steep learning curve
Permit requirements: Permits are usually required regardless, but licensed pros are used to handling them

DIY window installation makes the most sense for homeowners with carpentry skills doing ground floor, standard sized replacements. Other scenarios are often better left to the professionals.

Cost of Window Installation

Whether DIY or hiring an installer, the total costs for your window installation project include:

Windows: Replacement window units start around $200 for basic models but can cost $800 or much more for high end options
Labor: Professional installation averages $600 per window. DIY saves significantly on labor but increases time investment.
Permits & fees: Expect to pay $25 to $50 per window for local permitting fees.
Tools: DIY requires purchasing/renting tools which can add up. Pros have their own equipment.
Materials: Flashing, sealants, shims, and other materials average $50 to $100 per window.
Disposal: Removing and disposing old windows professionally costs around $50 each.

Find the exact cost of specific window types:

When pricing new windows, get contractor quotes and estimate DIY costs to make the best decision for your budget. Expect a single window DIY replacement to cost $300-$800 including the window itself.

How to Prepare for Installation

Proper planning prevents problems down the road. For either DIY or professional installs, make sure to complete the following preparatory steps:

Measure precisely: Remove sashes and interior trim to measure just the frame size for accurate new window ordering.
Research permits: Almost all jurisdictions require permits for window installations. Not obtaining them risks fines.
Buy all materials: For DIYers this includes tools, window units, flashing, shims, sealant, etc.
Schedule time: Window installation cannot be rushed. Make sure to block off ample time in your calendar.
Recruit help: Having an extra pair of hands makes a big difference for DIY projects. Offer food, drinks, or cash.
Talk to neighbors: Be considerate and give surrounding homes a heads up about the project, especially for outdoor work.

Thorough planning and preparation leads to efficient, problem-free window installation.

Step-By-Step Installation Process

The installation process follows the same general steps whether DIY or done professionally:

Remove interior stops, sashes, and trim from existing window
Detach frame from rough opening by cutting caulk seals and removing installation screws
Lift out old window and properly dispose
Thoroughly clean rough opening framing
Set new window into opening, shim as needed, and level and square frame
Anchor frame securely using installation screws driven into framing
Insulate any gaps around perimeter with minimal expansion foam
Seal interior gaps with caulk and reinstall stops, sashes, and trim
Cut exterior flashing tape to size and apply carefully around perimeter
Caulk exterior gaps and seams using premium sealant
Install exterior trim and finishes like stucco or siding for seamless exterior look
Operate window to test and make any final adjustments

The proper materials and techniques involved at each step are critical for correct installation and sealing.

Tips for DIY Success

Patience and meticulous attention to detail are key for DIY window installation success. To master DIY window installation:

Watch online tutorial videos to understand the entire process before starting
Invest in high-quality, purpose-built tools like pry bars, levels, and heavy duty caulk guns
Be extremely careful when removing old frames to avoid damaging surrounding walls
Have another person assist with lifting, positioning, and securing the window units
Take your time fully sealing the perimeter gaps for a watertight seal
Wear cut-resistant gloves when handling flashing materials
Be prepared to shim the window framing until perfectly level and plumb
Carefully test window operation and sealing before completing exterior finishes

DIY How-To Guides

Hiring the Right Window Installer

If hiring a professional, make sure to:

Get at least 3 quotes from reputable local contractors
Ask for proof of licensing, bonding, insurance and local permits
Verify they follow manufacturer specifications for your window units
Check reviews and references to confirm quality workmanship
Get everything in a written contract including timeline, warranty, and price
Avoid payments upfront if possible. Pay as work is completed.

We always recommend going with a local contractor when planning any home renovation project in an area where you don’t have direct expertise. That said, a single window replacement on a ground floor is a fairly common project for homeowners to undertake.

You’ll save a fair amount of money, but will only be left with the manufacturer warranty on the window and associated parts. You’d be without the protection that many window contractors’ labor warranties provide for faulty installation.