20 Best Window Companies in Pittsburgh, PA (2024 Reviews)

If you’re thinking about upgrading to new windows, our guide to the top window installation companies can help.

We analyzed all the top-rated window companies in Pittsburgh and selected the best 20 based on:

  • Customer reviews
  • Window installation expertise
  • Popularity with home-owners like you
EcoWatch Local Advisors

By EcoWatch Local Advisors

Updated June 24, 2024

Why you can trust EcoWatch

Our panel of energy experts work tirelessly to create unbiased reviews and informative content to help homeowners make educated decisions. No other windows site has covered energy efficiency and sustainability as long as EcoWatch, which means we're going to help you find windows replacements that will save on your energy bill and put more money back in your wallet.

A review of the top window installation companies in Pittsburgh may not seem like the most interesting article on EcoWatch, but trust us, windows have more of an impact on your life than you might think. The Department of Energy estimates that heat gained or lost through outdated or drafty windows could account for around 30% of residential energy climate usage. In Pittsburgh, where the electricity bills are an average of $38 per month, that’s almost $$136 per year wasted.

Installing efficient windows on your property can help you save money every month on your power bills — and you can help the environment, too.

As windows are so important for your home, selecting the best company for you is a big decision to make. That’s why the EcoWatch team has put together this list of the best window installation companies, so you can make an informed decision more easily.

Best Energy-Efficient Features

Champion

★★★★★
4.5
  • Many years of experience
  • Low prices relative to competitors
  • Limetime warranty
Save 35% + $100 off per window!
Get Estimate

Power Home

★★★★★
4.5
  • Uses eco-friendly materials
  • Well-trained, certified installers
  • Lifetime or lengthy warranty
Next-Day Appointments Available
Get Estimate

Best for Residential Windows

Window Nation

★★★★★
4.0
  • Custom Designs
  • Wide variety of products and services
  • Manufactures products in-house

Best Window Installation & Replacement Companies in Pittsburgh

The EcoWatch team assessed dozens of providers that service the Pittsburgh area to find the top window installation companies by our standards. We assessed the companies based on energy-efficient offerings, local experience, price, customer service, coverage area and more.

Window World logo
FAST QUOTE
as little as 30 seconds
Best Affordability

Window World

★★★★★
BBB Rating: A+
Locations: Nationwide
Founded: 1995
Pros:
  • Pros icon EnergyStar Partner
  • Pros icon Large serice area
  • Pros icon Low prices relative to competitors
  • Pros icon Great industry reputation
  • Pros icon Lifetime warranty
Cons:
  • Pros icon Quality of service will depend on your area

Window World provides windows expertise in Pittsburgh. It's the largest window replacement company in the country, known for its vinyl windows and affordability. Window World has been in the window industry for about 27 years.

If you’re looking for a company that is certified by the Environmental Protection Agency (EPA) and Energy Star and supports charities like St. Jude Children’s Research Hospital, this may be the perfect provider for you.

Energy Efficiency of Window World Windows

Window World carries some Energy Star windows, but note that not all its windows are energy-efficient, so make sure you mention that you want Energy Star windows when inquiring. Its high-performance Low-E (low-emissivity) coatings and argon gas insulation offer exceptional efficiency and performance for any home.

How much does Window World cost in Pittsburgh?

While pricing information is not available on Window World’s website, it's known for offering some of the most affordable window installations around. If you’d like to know for sure, you can get a quote on the company’s website.

Renewal by Andersen logo
FAST QUOTE
as little as 30 seconds
Best Overall

Renewal by Andersen

★★★★★
BBB Rating: A
Locations: Nationwide
Founded: 1995
Pros:
  • Pros icon Great industry reputation
  • Pros icon Award-winning company
  • Pros icon Member of US Green Building Council
  • Pros icon Manufactures products in-house
Cons:
  • Pros icon No lifetime warranty
  • Pros icon More expensive than competition

Renewal by Andersen provides the best availability in Pittsburgh. It's a subsidiary of the Andersen Corporation, a major manufacturer of windows and doors. Andersen has been in the window industry for about 27 years.

If you’re looking for a company that uses in-home estimates and advanced digital tools to help you plan and visualize your project before getting started, this may be the perfect provider for you.

Energy Efficiency of Renewal by Andersen Windows

Renewal by Andersen carries some Energy Star windows, but note that not all its windows are energy-efficient, so make sure you mention that you want Energy Star windows when inquiring. A handful of windows manufactured by the Andersen corporation were awarded Energy Star’s “Most Efficient” in 2021, and Andersen was named Energy Star’s Partner of the Year in 2019.

How much does Renewal by Andersen cost in Pittsburgh?

While pricing information is not available on Andersen’s website, based on customer feedback, you can expect to pay anywhere between $750 to $1,250 per window for an installation with Andersen. If you’d like to know for sure, you can get a quote on the company’s website.

Aeroseal Windows logo
FAST QUOTE
as little as 30 seconds
Best for Businesses

Aeroseal Windows

★★★★★
BBB Rating: A+
Locations: Regional
Founded: 1999
Pros:
  • Pros icon Many years of experience
  • Pros icon Great industry reputation
  • Pros icon Low number of customer complaints
  • Pros icon Manufactures products in-house
  • Pros icon Custom Designs
Cons:
  • Pros icon No lifetime warranty
  • Pros icon Not ideal for residential installations

Aeroseal Windows provides the best window installation for businesses in Pittsburgh. It's an installer that mainly serves commercial and multifamily properties, and also specializes in railings. If you’re looking for residential window installations, you should probably refer to one of the other companies on this list. Aeroseal has been in the window industry for about 23 years.

If you’re looking for a company that installs windows and doors at businesses across the Eastern U.S, this may be the perfect provider for you.

Energy Efficiency of Aeroseal Windows Windows

Aeroseal Windows carries some Energy Star windows, but note that not all its windows are energy-efficient, so make sure you mention that you want Energy Star windows when inquiring. The company claims it helps businesses save on energy expenses and reduce their carbon footprints with energy-efficient windows, as well as practices like Low-E glass coating, weatherstripping and more.

How much does Aeroseal Windows cost in Pittsburgh?

While pricing information is not available on Aeroseal’s website, it provides high-quality windows at a competitive price point. If you’d like to know for sure, you can get a quote on the company’s website.

Window Nation logo
FAST QUOTE
as little as 30 seconds
Best for Residential Windows

Window Nation

★★★★★
BBB Rating: A
Locations: Regional
Founded: 2006
Pros:
  • Pros icon Award-winning company
  • Pros icon Manufactures products in-house
  • Pros icon Custom designs
  • Pros icon Wide variety of products and services
Cons:
  • Pros icon Installation not covered by warranty
  • Pros icon Limited service area

Window Nation provides the best residential windows in Pittsburgh. It's a company that serves hundreds of thousands of homeowners, mostly in the mid-Atlantic region of the U.S. Window Nation has been in the window industry for about 16 years.

If you’re looking for a company that gives customers the opportunity to view products and to speak to a representative in person in its showrooms, this may be the perfect provider for you.

Energy Efficiency of Window Nation Windows

Window Nation carries some Energy Star windows, but note that not all its windows are energy-efficient, so make sure you mention that you want Energy Star windows when inquiring. Each product has windowpanes coated with a Low-E (low emissivity) glaze that prevents damaging UV rays from heating your home. Plus, the spaces between double- and triple-pane windows are filled with argon gas that’s been proven to improve home insulation.

How much does Window Nation cost in Pittsburgh?

While pricing information is not available on Window Nation’s website, based on customer feedback, you can expect to pay between $300 and $525 per window installed, making it a more affordable option compared to competitors. If you’d like to know for sure, you can get a quote on the company’s website.

We aim to stay unbiased and transparent by including pros and cons for every company we review. Additionally, our rankings are not affected by any partnerships.

More Window Companies in Pittsburgh

Power Home Remodeling

Coraopolis, PA
4.8
★★★★★
  • Pros icon Good Customer Service
  • Pros icon Full-home remodeling
  • Pros icon Energy-efficient
  • Pros icon Lifetime labor warranty

Services Offered

  • Service icon Window Replacement/Installation
  • Service icon Energy-Efficient Options

Website: https://powerhrg.com/
Address: 1325 Cherrington Pkwy Suite 300, Coraopolis, PA 15108
Phone: (484) 483-6216

Window Nation

Monroeville, PA
4.7
★★★★★
  • Pros icon award_winning
  • Pros icon Good Customer Service
  • Pros icon Educational Website
  • Pros icon Free Assessment
  • Pros icon Price Transparency

Services Offered

  • Service icon Glass Doors
  • Service icon Window Replacement/Installation
  • Service icon Double-Hung
  • Service icon Energy-Efficient Options
  • Service icon Vinyl Frames
  • Service icon Custom Window Designs
  • Service icon Bay Windows

Website: https://www.windownation.com/replacement-windows-pittsburgh/
Address: 9001 Rico Dr, Monroeville, PA 15146
Phone: (412) 357-2760

Specialty Window & Door

West Homestead, PA
5.0
★★★★★
  • Pros icon Good Customer Service
  • Pros icon Locally owned & operated
  • Pros icon Price Transparency
  • Pros icon Free Assessment
  • Pros icon Educational Website
  • Pros icon Variety of styles & materials
  • Pros icon Free in-person consultation

Services Offered

  • Service icon Glass Doors
  • Service icon Double-Hung
  • Service icon Bay Windows
  • Service icon Energy-Efficient Options
  • Service icon Custom Window Designs
  • Service icon Window Replacement/Installation

Website: http://specialtywindowanddoor.com/
Address: 1206 Breezewood Dr, West Homestead, PA 15120
Phone: (412) 462-7375

"ALL-NU" Windows

Oakdale, PA
5.0
★★★★★
  • Pros icon Educational Website
  • Pros icon Price Transparency
  • Pros icon Meet or beat pricing policy
  • Pros icon Family-owned & operated
  • Pros icon Financing options available

Services Offered

  • Service icon Window Replacement/Installation

Website: http://allnuwindows.net/
Address: 1012 Franklin St, Oakdale, PA 15071
Phone: (412) 279-1717

Windows Pittsburgh

Pittsburgh, PA
4.9
★★★★★
  • Pros icon Educational Website
  • Pros icon Financing options available
  • Pros icon Good Customer Service
  • Pros icon Custom window designs
  • Pros icon Free Assessment
  • Pros icon Price Transparency
  • Pros icon Full-service window replacement

Services Offered

  • Service icon Window Replacement/Installation
  • Service icon Vinyl Frames
  • Service icon Energy-Efficient Options
  • Service icon Glass Doors
  • Service icon Bay Windows
  • Service icon Double-Hung
  • Service icon Custom Window Designs

Website: http://www.windowspittsburgh.com/
Address: A Corporate office Appointment Required, 220 Shady Knoll Dr Suite 2, Pittsburgh, PA 15220
Phone: (412) 279-1112

Metropolitan Window Company

Pittsburgh, PA
4.9
★★★★★
  • Pros icon award_winning
  • Pros icon High performance
  • Pros icon Variety of styles & materials
  • Pros icon Free Assessment
  • Pros icon Price Transparency
  • Pros icon Educational Website
  • Pros icon Good Customer Service
  • Pros icon Financing options available

Services Offered

  • Service icon Double-Hung
  • Service icon Glass Doors
  • Service icon Bay Windows
  • Service icon Window Replacement/Installation
  • Service icon Energy-Efficient Options
  • Service icon Wood Frames
  • Service icon Fiberglass Frames

Website: https://www.metropolitanwindows.com/
Address: 4672 Clairton Blvd, Pittsburgh, PA 15236
Phone: (412) 655-8411

Allegheny Millwork & Lumber

Pittsburgh, PA
4.8
★★★★★
  • Pros icon Good Customer Service
  • Pros icon Educational Website
  • Pros icon Price Transparency

Services Offered

  • Service icon Glass Doors
  • Service icon Energy-Efficient Options
  • Service icon Skylights
  • Service icon Window Replacement/Installation

Website: http://www.alleghenymillworklumber.com/
Address: 1001 Muriel St, Pittsburgh, PA 15203
Phone: (412) 431-4224

Legacy Remodeling

Pittsburgh, PA
4.8
★★★★★
  • Pros icon Free Assessment
  • Pros icon Educational Website
  • Pros icon Price Transparency
  • Pros icon award_winning
  • Pros icon Good Customer Service

Services Offered

  • Service icon Energy-Efficient Options
  • Service icon Wood Frames
  • Service icon Window Replacement/Installation
  • Service icon Glass Doors
  • Service icon Glass Showers

Website: http://www.legacyremodeling.com/
Address: 3090 W Liberty Ave, Pittsburgh, PA 15216
Phone: (724) 573-8118

Ireland Contracting, LLC

Glenshaw, PA
4.8
★★★★★
  • Pros icon award_winning
  • Pros icon Timely Service
  • Pros icon Educational Website
  • Pros icon Free Assessment
  • Pros icon Good Customer Service
  • Pros icon Price Transparency

Services Offered

  • Service icon Energy-Efficient Options
  • Service icon Skylights
  • Service icon Window Replacement/Installation

Website: https://irelandcontracting.com/
Address: 1310 William Flinn Hwy, Glenshaw, PA 15116
Phone: (800) 639-7663

Mr. Handyman of Northern Pittsburgh, South Hills, Moon

Pittsburgh, PA
4.8
★★★★★
  • Pros icon Free Assessment
  • Pros icon Price Transparency
  • Pros icon Good Customer Service
  • Pros icon Family-owned & operated
  • Pros icon Timely Service
  • Pros icon Educational Website
  • Pros icon Quality workmanship guarantee
  • Pros icon Full-service installation

Services Offered

  • Service icon Window Replacement/Installation

Website: https://www.mrhandyman.com/northern-pittsburgh/
Address: 1511 Parkway View Dr Building 15, Pittsburgh, PA 15205
Phone: (724) 923-4377

American Window Industries Inc.

Pittsburgh, PA
4.8
★★★★★
  • Pros icon Price Transparency
  • Pros icon Educational Website
  • Pros icon Good Customer Service

Services Offered

  • Service icon Window Replacement/Installation

Website: http://www.americanwindowpittsburgh.com/
Address: 106 Rockwood Ave, Pittsburgh, PA 15221
Phone: (412) 823-2320

Dun-Rite Window & Door

Pittsburgh, PA
4.7
★★★★★
  • Pros icon Price Transparency
  • Pros icon Good Customer Service
  • Pros icon Timely Service
  • Pros icon award_winning
  • Pros icon Free Assessment
  • Pros icon Educational Website

Services Offered

  • Service icon Glass Doors
  • Service icon Window Replacement/Installation
  • Service icon Window Repair

Website: http://www.getitdun-rite.com/
Address: 718 Main St, Pittsburgh, PA 15215
Phone: (412) 781-8200

West Shore Home

Pittsburgh, PA
4.7
★★★★★
  • Pros icon Good Customer Service
  • Pros icon Free Assessment
  • Pros icon Price Transparency
  • Pros icon Educational Website

Services Offered

  • Service icon Glass Doors
  • Service icon Custom Window Designs
  • Service icon Window Replacement/Installation
  • Service icon Energy-Efficient Options
  • Service icon Bay Windows
  • Service icon Double-Hung
  • Service icon Glass Showers

Website: https://westshorehome.com/locations/pittsburgh-pa/
Address: 460 Rodi Rd, Pittsburgh, PA 15235
Phone: (412) 530-0729

Universal Windows Direct of Pittsburgh

Pittsburgh, PA
4.6
★★★★★
  • Pros icon Free Assessment
  • Pros icon Financing options available
  • Pros icon Price Transparency
  • Pros icon Educational Website
  • Pros icon Custom window designs
  • Pros icon Good Customer Service
  • Pros icon Exterior remodeling
  • Pros icon award_winning

Services Offered

  • Service icon Energy-Efficient Options
  • Service icon Glass Doors
  • Service icon Vinyl Frames
  • Service icon Window Replacement/Installation

Website: https://www.universalwindowsdirect.com/pittsburgh
Address: 611 Parkway View Dr Unit 6, Pittsburgh, PA 15205
Phone: (412) 222-5200

Monroeville Glass Block LLC

Verona, PA
4.6
★★★★★
  • Pros icon Educational Website
  • Pros icon Good Customer Service
  • Pros icon Price Transparency
  • Pros icon Free Assessment

Services Offered

  • Service icon Window Replacement/Installation
  • Service icon Glass Showers

Website: https://www.monroevilleglassblock.net/
Address: 4356 Verona Rd, Verona, PA 15147
Phone: (412) 731-8559

Window Installation Specialists

Pittsburgh, PA
4.5
★★★★★
  • Pros icon award_winning
  • Pros icon Free Assessment
  • Pros icon Good Customer Service
  • Pros icon Educational Website
  • Pros icon Price Transparency

Services Offered

  • Service icon Bay Windows
  • Service icon Glass Doors
  • Service icon Wood Frames
  • Service icon Vinyl Frames
  • Service icon Custom Window Designs
  • Service icon Fiberglass Frames
  • Service icon Window Replacement/Installation

Website: https://windowinstallationpittsburgh.com/
Address: 3945 Forbes Ave #462, Pittsburgh, PA 15213
Phone: (724) 446-0275

Pittsburgh Window & Door Co

Pittsburgh, PA
4.5
★★★★★
  • Pros icon Free Assessment
  • Pros icon Price Transparency
  • Pros icon Good Customer Service

Services Offered

  • Service icon Wood Frames
  • Service icon Window Replacement/Installation
  • Service icon Glass Repair
  • Service icon Glass Doors
  • Service icon Energy-Efficient Options
  • Service icon Vinyl Frames
  • Service icon Screen Repair

Website: http://www.pghwindowdoor.com/
Address: Stock House, 100 Evergreen Ave, Pittsburgh, PA 15209
Phone: (412) 821-4322

Forest Knoll Construction

Pittsburgh, PA
4.5
★★★★★
  • Pros icon Free Assessment
  • Pros icon Educational Website
  • Pros icon Good Customer Service
  • Pros icon Price Transparency

Services Offered

  • Service icon Window Replacement/Installation

Website: https://www.forestknollconstruction.com/
Address: 4885A McKnight Rd Suite 195, Pittsburgh, PA 15237
Phone: (412) 932-3095

Joyce Windows, Sunrooms & Baths - Pittsburgh

Pittsburgh, PA
4.5
★★★★★
  • Pros icon Price Transparency
  • Pros icon Free Assessment
  • Pros icon Good Customer Service
  • Pros icon award_winning
  • Pros icon Educational Website

Services Offered

  • Service icon Vinyl Frames
  • Service icon Glass Doors
  • Service icon Glass Showers
  • Service icon Double-Hung
  • Service icon Window Replacement/Installation
  • Service icon Energy-Efficient Options
  • Service icon Bay Windows

Website: https://joycefactorydirect.com/
Address: 4583 Campbells Run Rd, Pittsburgh, PA 15205
Phone: (412) 538-5194

Pittsburgh's Best Remodeling Contractors - Honest Renovators

Pittsburgh, PA
4.4
★★★★★
  • Pros icon Free Assessment
  • Pros icon Good Customer Service
  • Pros icon Educational Website
  • Pros icon Price Transparency

Services Offered

  • Service icon Glass Showers
  • Service icon Window Replacement/Installation
  • Service icon Energy-Efficient Options

Website: http://honestrenovators.com/
Address: 5424 Walnut St 2nd Floor, Pittsburgh, PA 15232
Phone: (412) 212-6534
Pittsburgh Window Cost Calculator

Calculate how much you can expect to pay for window installation and replacement in Pittsburgh, PA using our customized window cost calculator.

Estimated Window Cost:
161 homeowners have requested a free estimate in the last 3 days.

Estimates will vary based on window dimensions and other unique factors to your home. Getting in touch with a local window installer is the best way to get an accurate cost estimate for your home.

How Installing Energy-Efficient Windows in Pittsburgh Saves You Money

When you upgrade to energy-efficient windows, you may see some perks, including:

  • Save on electricity bills: According to the Department of Energy, heat gained or lost through windows accounts for around 25-30% of residential energy use. Upgrading to energy-efficient models can help reduce how much energy is used in your home, therefore saving you about 12% more on your bills.
  • Decrease your carbon footprint: By using less energy after you upgrade to energy-efficient windows, you’ll also be cutting your indirect greenhouse gas emissions by about 12%, according to Energy Star.
  • Protect your valuables: Many energy-efficient windows have low-emissivity coatings, which not only provide better insulation for your home, but also filter out damaging UV rays, preventing your furniture, carpet and other valuables from fading.
  • Protect your investment: When you have an older home, your windows could also be outdated or drafty. Upgrading and repairing your windows is an important part of maintaining your property and its value.

Estimated Cost of Window Replacement in Pittsburgh

Each window replacement company provides varying services and has different costs based on several factors.

How Much Do New Windows Cost?

On average, homeowners in Pittsburgh can expect that most window installations will cost between $250 and $1,200, with the most common installations sitting at around $600. These figures vary depending on the specifics of your installation, such as size, material, type, the location of your home, number of windows and more.

Whether or not you want to install energy-efficient windows is another factor that will influence the cost. These will usually cost more than other windows, but on the other hand, you can save about $313 a year on your energy bills in Pittsburgh.

Another factor that influences the overall cost is the material of the frame you select. Aluminum frames are generally the least pricey and are sturdy and light, but they offer poor insulation. On the other hand, wood frames cost the most, as they are aesthetically pleasing and offer decent insulation. Fiberglass and vinyl frames provide good insulation as well and cost somewhere between the other two.

What Services do Window Installers Offer?

In general, there are two types of window replacement services companies provide: full-frame and pocket installations.

A full-frame installation replaces the full window, such as the sill, frame, trim and the window panes. Because this kind of installation is more involved, it will be more expensive than a pocket installation. Pocket installations are simpler and won’t cost as much, as they entail merely replacing the window within its existing frame. But if the frame has any damage or rot, you may need a full-frame installation instead.

Your window installer can help you decide which type of installation you should get.

Best Energy-Efficient Features

Champion

★★★★★
4.5
  • Many years of experience
  • Low prices relative to competitors
  • Limetime warranty
Save 35% + $100 off per window!
Get Estimate

Power Home

★★★★★
4.5
  • Uses eco-friendly materials
  • Well-trained, certified installers
  • Lifetime or lengthy warranty
Next-Day Appointments Available
Get Estimate

Best for Residential Windows

Window Nation

★★★★★
4.0
  • Custom Designs
  • Wide variety of products and services
  • Manufactures products in-house

How We Choose the Best Window Installers in Pittsburgh

In our hunt to find the most reliable, eco-friendly window installers in Pittsburgh, the EcoWatch team examined dozens of companies before deciding on these. We’ve assessed the best window installers in Pittsburgh primarily based on energy efficiency, as the most sustainable option also benefits homeowners in many ways. Energy Star certified windows can lower energy bills by hundreds of dollars. Along with energy efficiency, our rating methodology takes the following factors into consideration:

Service Area

This one is self-explanatory, but we’ve chosen to highlight window installers that serve a wide variety of states and cities so you can find the right window installation company near you.

Work Quality

We’re willing to bet that you’re looking for a company to do a great job installing windows. We’ve vetted each company in our guide to make sure its technicians are well-qualified and that the company has received lots of positive customer feedback to vouch for its service.

Customer Reviews

Customer feedback is another very important review factor. If the majority of customers don’t have positive feedback about their experience with a certain window installation company, it won’t be featured on EcoWatch.

Cost

Cheaper windows certainly don’t mean better windows, but we know many of our readers try to keep costs low when possible. When analyzing the prices of providers, we gave higher scores to companies with reasonable prices and accessible financing rather than “cheaper” services.

Warranty

As discussed, windows are a hefty investment, so you’ll want to be certain that investment is protected. Window installation companies that provide lengthy warranties for products, parts and installation (aka workmanship) rank higher with EcoWatch.

Years of Experience

Last but not least, we like to see companies that have been in the industry for quite some time. Window installers that have more years of experience are going to earn higher rankings by our standards. We like to see at least ten years of experience.

Pittsburgh, PA Window Replacement FAQs

How much does window installation cost?

The national average cost to install a single window is about $600 but can range between $200 and $1,200, based on several factors. The price is generally dependent on the size of the window, the type and material of the window and the location of your property. Also, bear in mind that energy-efficient windows may cost more upfront but can save you a decent amount of money a year in energy bills.

Which type of window is the best?

Generally, double-pane windows will be more efficient than single-pane windows and windows that do not open are more efficient than windows that do. To be sure you’ll get the most energy-efficient windows, look for models that have the blue Energy Star certification attached to them — they’re certified energy-efficient by the U.S. Department of Energy.

What services do window replacement companies do?

Window installers go to your home to remove your old windows and replace them with new ones. Some providers install products distributed by other companies, whereas others install their own windows. The installer will also clean up after the installation.

Should I replace my windows all at the same time?

If your windows are greater than 20 years old, it’s most likely time to replace all of them. By that point, they are typically less efficient, draftier and/or more damaged than new windows. Replacing your windows all at the same time will involve less paperwork and less stress.