Diamond Certified Companies are Rated Highest in Quality and Helpful Expertise.

  • Why this rating is the most accurate.
  • Our editors gather deep company info.
  • Performance is Guaranteed.

Diamond certified companies are top rated and guaranteed

Why Trust Diamond Certified Window Companies Rated Highest in Quality?

Decorative multi-pane windows and a custom window pergola installed by a Diamond Certified window contractor dress up the exterior of this home. You will have confidence choosing a quality window installers listed above because each has been rated Highest in Quality and has earned Diamond Certified. For more information on the best practices for choosing and working with good window companies in Alameda County, read the following articles. Photo: Larsen Construction (2012) Topic: Finding High Quality Window Contractors in Alameda County

OAKLAND — You are the customer. If your goal is to choose a window company that will deliver high customer satisfaction and quality, you’ll feel confident in choosing a Diamond Certified window contractor. Each has been rated Highest in Quality in the most accurate ratings process anywhere. And you’re always backed by the Diamond Certified Performance Guarantee. Here’s why the Diamond Certified ratings and certification process will help you find a top-rated window company and is unparalleled in its accuracy, rigor and usefulness:

1) Accuracy: All research is performed by live telephone interviews that verify only real customers are surveyed, so you’ll never be fooled by fake reviews.

2) Statistical Reliability: A large random sample of past customers is surveyed on an ongoing basis so the research results you see truly reflect a Diamond Certified company’s top-rated status.

3) Full Disclosure: By clicking the name of a company above you’ll see the exact rating results in charts and read verbatim survey responses as well as researched articles on each qualified company.

4) Guaranteed: Your purchase is backed up with mediation and the Diamond Certified Performance Guarantee, so you can choose with confidence.

Click on the name of a Diamond Certified company above to read ratings results, researched articles and verbatim customer survey responses to help you make an informed decision.

More than 200,000 customers of local companies have been interviewed in live telephone calls, and only companies that score Highest in Quality in customer satisfaction–a 90+ on a 100 scale–as well as pass all of the credential-based ratings earn Diamond Certified. By requiring such a high score to qualify, the Diamond Certified program eliminates mediocre and poorly performing companies. Read detailed information about the ratings and certification process.

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Kevin Gundry is a 28-year veteran of the home improvement industry and CFO of Custom Exteriors, Inc., a Diamond Certified company. He can be reached at (877) 312-3507 or by email.

Kevin Gundry

diamond certified contributor profile and expert article

Kevin Gundry: Customizing Success

By James Florence, Senior Writer

PLEASANTON — After nearly a decade in the home improvement industry, Kevin Gundry took a seminal step to customize his professional destiny. “I got into selling home improvements back in 1989,” he recounts. “After working for a couple of different companies, I partnered with my friend, Jeff Kendall, to found Custom Exteriors in 1997. At first, we were basically going door to door, throwing flyers onto driveways and cold-calling past contacts. We grew substantially during the following decade, nearly doubling our business each year. When the 2008 crash hit, we had to weather some hard times, but we hung in there and have since been on the rise.”

Today, as CFO of Custom Exteriors, Inc., Kevin says his favorite part of his job is transforming people’s homes with exterior upgrades. “It’s amazing how something as simple as replacing windows can make a home look so much better. It’s really neat to see the impact of our work and get positive feedback from customers who have seen an improvement in their homes’ look and performance.”
A resident of Danville (where he lives with wife, Bianca, and their children), Kevin expresses his appreciation for life in the Bay Area. “I think the Bay Area is one of the best places in the world. With five kids, my wife and I don’t get to travel much, so it’s nice that we at least get to live in such a beautiful and diverse place.”

When he’s not working, Kevin likes to spend as much time as possible outdoors. “I’m a big backpacker—I probably backpack 100 miles every summer,” he details. “My goal is to backpack along the entire Pacific Crest Trail from Mexico to Oregon, and every year I do another chunk of it.” Besides backpacking, Kevin enjoys fishing, camping and spending time with his family.

In regard to his career, Kevin espouses the importance of quality over quantity. “While we’re happy to see our company growing again, we don’t want to grow just for growth’s sake,” he explains. “After all, you can be a huge company, but if you aren’t making your customers happy, what good is it? That’s why we pay close attention to efficient management and customer satisfaction, with the goal of continually improving the way we run our business. By staying focused on what matters most, we hope to continue growing in both size and excellence.”

When asked the first thing he’d do if he were to retire tomorrow, Kevin says he’d do some long-deferred traveling. “I’d visit some countries I’ve never been to, which at this point is most of them,” he laughs. “The truth is, I’ve only been to Canada and Mexico, so there’s a whole lot more world for me to see. Of course, I would also spend more quality time with my family.”

Ask Me Anything!

Q: Are you an early bird or a night owl?
A: An early bird.

Q: What’s your favorite sports team?
A: The Oakland Raiders.

Q: What’s your favorite TV show?
A: “The Walking Dead.”

Q: Music or talk radio?
A: Talk radio—mostly sports.

Q: What’s your favorite thing to eat for dessert?
A: Chocolate ice cream.

Read more

Upgrading Your Window Glass


PLEASANTON — These days, double-pane glass is standard for new windows. That’s why, when a homeowner replaces their old, single-pane windows with new, double-pane ones, they assume they’re getting the best technology available. However, these homeowners don’t realize that all window glass… Read more

Double-Pane Window Innovations


PLEASANTON — Double-pane windows have come a long way over the last decade, with today’s products incorporating several performance-enhancing innovations. One such innovation is the development of Low-E 366 glass, which contains layers of silver oxide that reflect radiant heat… Read more

Expert Video Tip

Video: Best Window Glass for Sound Suppression

Complete Video Transcription:

PLEASANTON — Host, Sarah Rutan: When replacing your home’s windows, consider upgrading to a glass product that offers maximum sound suppression. Today we’re in Pleasanton with Diamond Certified… Read more




American Craftsman
Andersen Windows
Anlin Window Systems
CertainTeed Windows
Champion Windows
Empire Pacific
Jeld-Wen Windows
Kolbe Windows
Kolbe Millwork
Loewen Windows
Marvin Windows
Milgard Windows
Norco Windows
Pella Windows
PGT Windows
Silver Line Windows
Simonton Windows
Weather Shield Windows

replacement windows
new windows
vinyl window installation
casement window installation
aluminum windows
window sash repair
window replacing
wood window installation
double-hung windows
wooden window repairs
home window replacements
storm window installation
vinyl replacement windows
picture window replacement
install exterior windows
window screen repair
awning windows
home window repair
insulated windows
single window pane replacement
jalousie window installation
window sash replacement
broken window repair
crank windows
bay replacement windows
retrofit windows
replace sliding windows
window weather-stripping
basement window repair

Castro Valley
Komandorski Village
Mount Eden
Russell City
San Leandro
San Lorenzo
Sunol and Union City


American Window and Door Institute (AWDI) (www.awdi.com)
California Association of Window Manufacturers
Energy Star (www.energystar.gov)
Efficient Windows Collaborative (EWC) (www.efficientwindows.org)
National Fenestration Rating Council (NFRC) (www.nfrc.org)
Stained Glass Association of America (http://stainedglass.org)
Window & Door Manufacturers Association (WDMA) (www.wdma.com)

Know What You Want
Determine Your Objectives for Your New Windows

Before you make your initial phone calls or meet in person with local window contractors in Alameda County, you’ll want to have a clear idea of the scope of your project, the type of windows you want and what you’re looking for in a contractor.

Writing down ideas and keeping a file of questions and samples will also help you present a clear and coordinated list to the contractors. This way, you’ll get comparable answers based on the exact criteria from each company. The following are some questions to ask yourself as you prepare to interview local window contractors.

  1. Do I want a Diamond Certified company that is rated best in quality and backed by the Diamond Certified Guarantee?
  2. What is my overall purpose in having my home windows replaced?
  3. Are new windows or replacement windows a better fit for my needs?
  4. What is my budget for window replacement?
  5. What type of material do I want the windows to be made from?
  6. Do I need energy efficient windows or other special types of new windows?
  7. Is there a specific design aesthetic or look I want?
  8. Do I plan to live in my home long-term, or is it a rental property or house I plan to sell soon?
  9. What characteristics do I want in an Alameda County window company? (This could include communication skills, ability to start the job right away, sticking to the schedule throughout the job, long warranties and guarantees, and follow-up services.)
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What To Ask In Person
Questions to Ask When You Meet Alameda County Window Contractors in Person
  • How much time will the work take, from ordering the new windows to installation?
  • Will I be able to stay in my home while the work is ongoing?
  • Will my new windows reduce my electric bills?
  • How do you finish windows after installation? If I want the window frames painted or stained, will I have to hire a second contractor?
  • How should I handle any service issues after my window installation? Are you responsible for warranty work if there’s ever a problem with my new windows?
  • Do you have customer references I can call?
  • Do you have any recent projects in my area of Alameda County where I can see how the windows look from the street?
  • What can I do to make this process faster and easier?
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  • What To Ask References
    Benefit From Previous Customers' Experiences with Local Window Contractors in Alameda County

    It’s best to choose Diamond Certified window contractors because all certified companies have passed an in-depth ratings process that most other companies can’t pass.

    If you want quality from a window company in Alameda County, you’ll have confidence choosing a Diamond Certified company. Diamond Certified reports are available online at www.DiamondCertified.org for all certified companies. And you’ll never have to worry about being fooled by fake reviews because all research is performed in live telephone interviews.

    If you can’t find a Diamond Certified window contractor within reach, you’ll have to do some research yourself. It’s wise to call references provided by your window company.

    Keep in mind, though, that references provided to you by the contactors are not equal in value to the large random sample of customers surveyed during the Diamond Certified ratings process. References given to customers by the companies themselves are often cherry-picked instead of randomly selected from all their customers.

    If you do ask for references, request a list of 10 of the company’s most recent customers. This will help avoid them giving you only the names of customers they know were satisfied. References can give you an insider’s view on how the Alameda County window contractors performed on previous jobs. So call several past customers and ask specific questions.

    Here are some sample questions to ask references:

    1. Were you satisfied with the window installation and the service from _(window company name)_?
    2. What was the type and scope of job they did for you (window replacement, window repair, whole house window installation, etc.)?
    3. Did the Alameda County window contractor you hired complete the work on time?
    4. Did the contractor keep you up-to-date on the status of the project?
    5. Were there unexpected costs? If so, what were they?
    6. If you live in a smaller town such as Albany, Castro Valley, Emeryville, San Lorenzo, in the Tri-Valley, or in the unincorporated areas of Cherryland, Komandorski Village, Mount Eden or Russell City, did they charge extra to travel to your home?
    7. Did the window installers show up on time?
    8. Did they clean up after the window installation?
    9. If you need new windows in the future, would you use this window contractor again?
    10. Would you recommend them to others?
    11. Can I visit your home to see the completed window installation?
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  • Review Your Options
    Be Sure You're Hiring Good Window Companies in Alameda County

    The Diamond Certified symbol has been awarded to companies that scored Highest in Quality in an accurate ratings process.

    Your choice of window contractors impacts every part of your job, from the ease of installation to how long your new windows last. So before deciding on the best window contractor in Alameda County for you, it’s important to consider the following questions.

    1. Can an Alameda County window contractor meet your needs in terms of scheduling, products and installation requests?
    2. Are they knowledgeable on the brands and products they sell and install? Can they tell you which windows best suit your needs and why (i.e. aluminum windows, energy efficient windows / insulated windows, vinyl windows, wood windows)?
    3. Is the window installation company sensitive to your budget?
    4. Can they offer various products that fit your resources? Many contractors will give you Good, Better and Best options with your choice of products, design, prices, manufacturers and additional services.
    5. Do the window contractors in Alameda County you’re considering offer warranties for product failure or installation errors?
    6. Will they put their guarantees in writing?

    It’s also smart to note your own expectations. Some may not be congruous with the project and can contribute to dissatisfaction with a job that’s actually well-done.

    For example, it may not be realistic to expect a consistent schedule or a quiet worksite when having new windows installed. You’re most likely to be satisfied when you talk with your contractor before the job and discuss realities and expectations from both your view and theirs.

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  • How To Work With
    Attract Bids from the Best Local Window Installers in Alameda County

    In this buyer’s market, you might be surprised to find you’re not the only one who is interviewing and selecting potential candidates. Alameda County window companies, including those in the larger cities of Hayward, San Leandro, Newark, Fremont, Oakland and Berkeley and even some in the smaller towns, can also be selective about which jobs they accept. Bids take time and expense to prepare, and many contractors have lost money and faced difficult dealings with unreasonable homeowners. That can make them choosy about with whom they do business. So it’s reasonable that some local window contractors show a lack of interest or don’t respond to all job requests.

    There are some ways you can encourage good window contractors to bid on your job.

    • Shop among local window contractors in Alameda County. Most prefer to stay in the local area, as it enables them to provide better, more timely service. It also shows that you’re serious about quality products and good installations. That’s important because some questionable contractors travel long distances to install cheap products that local contractors can’t compete with price-wise.
    • Be honest about the fact that you’re accepting other bids and interviewing other window contractors. But assure them you’re gathering just a few bids, not dozens.
    • Look for good value, not just lowest price. The first question that contractors often hear is about price, so it’s important to show them you understand the importance of quality and overall value.

    Get the Most Out of Your Deal with Alameda County Window Contractors
    You’ve finally found the perfect Alameda County window contractor that meets all your requirements. Now is the time to ask for a window installation contract that includes price, product and timing guidelines. They should also be willing to provide you with a written timeline that covers the job start date, major milestones and intended completion date along with areas of specific concern.

    The contract you sign with an Alameda County window company should protect you, your property and your contractor. For this reason, never sign a blank or incomplete estimate. Read the entire contract and understand the terms before you sign it. And don’t be afraid to write in your own requests or put in writing the verbal agreements you’ve made with your representative.

    For instance, start and end dates are important, but there are factors you and your installer can’t control, such as the weather. That’s why it’s a smart idea to add a no-later-than clause to your contract. This stipulates the date by which all work must be completed. Even if inclement weather or problems with the products delay installation, this clause will give you assurance that your job will be finished on time. If a quick turnaround is important to you, you may want to consider adding a bonus for early completion to your contract as well.

    Confirm warrantees at this time, as some window installers in Alameda County only guarantee certain brands or installation techniques. Also verify that manufacturer warrantees apply to the windows you’re having installed.

    Don’t forget about related issues that may not be covered by a standard contract. For example, regardless of how careful your window installer promises to be, crushed flowers, damaged shrubs and rutted lawns are often unexpected hazards that come with hiring a window contractor in Alameda County. But you can protect yourself and your property by being proactive. Before work begins, ask the job supervisor to accompany you on a pre-work inspection to determine the original condition of the property. List or photograph your landscaping and property before the work begins, and talk with your contractor about reasonable expectations for protecting your home and yard during the window installation process. When you’ve reached an agreement about the condition of the property, both you and the contractor should sign and date the document. After the work is done, do a final inspection together to confirm your expectations were met.

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  • Be a Good Customer
    How Can YOU Be a Good Window Company

    It’s the window company’s responsibility put in quality windows using the best possible installation techniques. But you play a big part in the success of your new window installation, too. Here are a few simple steps you can take to be a good customer when hiring an Alameda County window contractor.

    • Be clear and upfront with the window contractor or window company representative. Let them know what you want from your windows, the long-term outcome you’re expecting and specific ways they can satisfy your expectations.
    • Remember, a friendly smile goes a long way!
    • Before you hire a window contractor in Alameda County, restate your expectations and goals, and reiterate to the window company representative your understanding of the agreement. Most problems with local window contractors occur because of a breakdown in communication. By clearly outlining your expectations and theirs, you can avoid most conflicts.
    • Ask your window installer if you should call to check on the progress or if he will call you with updates.
    • Be sure your service representative has a phone number where they can reach you at all times while they’re installing your new windows. The work will move along more smoothly if your window company can reach you for any necessary updates, questions or work authorizations.
    • When your contractor contacts you, return calls promptly to keep the window installation on schedule.
    • Pay for the new windows and installation work promptly.

    Why would you want to be a good customer? Window installation contractors in Alameda County appreciate customers who are straightforward, honest and easy to work with. Your good customer behavior sets the tone from your end and creates an environment conducive to a good relationship. Things may very well go smoother and any problems more easily resolved.

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Check The Work
Check the Window Installation Against the Written Invoice

When the work is completed, most good window contractors in Alameda County will give you a written invoice that details all the work done.

Complete invoices usually include the following:

  • The name of the window contractor and their physical office address.
  • A list of all window installation work performed.
  • An itemized list of all new windows or window replacement parts.
  • The total window installation cost, including the amount due for labor.
  • Any applicable warrantees or guarantees provided by the window manufacturers or the window installers.

It’s smart to compare written invoices to the work that was actually done. Ask your window company representative to walk through the job with you and show you the window repairs and installation. Check this work against the invoice. Your window company should be willing to talk you through the process and give you any special instructions for operating your new windows and maintaining them over the life of the product.

If you have questions about what work was done or how the installation was completed, this is the time to ask. It may be harder to get answers from window contractors after they’ve moved on to new window replacement jobs.

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Written Warranties
Ask the Alameda County Window Installers for Written Guarantees

Before the Alameda County window contractors leave the jobsite, confirm your warranties. Not all window companies in Alameda County guarantee their work. But if the window contractor you’ve chosen does guarantee the new windows and window installations they provide, they should give you a written warranty, including:

  • The window contractor’s name, license number and physical address.
  • Terms of and limitations on the new window warranty -including whether the contractor will give you a refund or replace/repair your windows if you have a warranty claim. Any exclusions should be in writing.
  • Your responsibility if you need warranty work or replacement windows (i.e., if you have to pay for labor when filing a claim for window warranty work or pay a prorated amount).
  • If the new window warranty coverage is transferrable to the new owner if you sell your home.
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Top 10 Requests
Homeowners' Top Requests for Alameda County Window Contractors

The top requests for new windows and replacement windows are available in cities throughout Alameda County. Read the paragraphs below for the definition of each type of window service and product.

New Windows
New windows are a complete new window unit that’s usually installed in new homes and remodels. New windows differ from replacement windows because they have a nailing fin along the outer frame and are affixed from the outside of the home before siding or exterior trim is installed. New windows may be more expensive than replacement windows, but their installation is much more involved.

Replacement Windows
When existing windows deteriorate, replacement windows are often the solution to upgrade efficiency, security and appearance. Alameda County window contractors usually install replacement windows in existing window spaces, using the existing trim and cladding. Drop-in replacement windows are designed for minimal disruption of the existing structure and are often the least expensive option.

Window Repair Services
Window installers in Alameda County are often asked to repair old windows and windows that have been broken. Some contractors specialize in repairing and restoring old windows to maintain historic homes. Others repair window frames and provide routine maintenance for modern windows.

Vinyl Windows and Vinyl Window Replacements
Vinyl windows are a favorite of Alameda County homeowners in Oakland, Pleasanton, Hayward, Dublin and other cities because they are inexpensive, durable, energy efficient and nearly maintenance-free. Vinyl windows have vinyl frames that may be painted or can be ordered in colors to match your home’s exterior or interior.

Aluminum Windows
Known as strong, durable and easy-to-configure, aluminum windows are often used to showcase beautiful views. They are also a less-expensive option in homes and light commercial buildings. Aluminum windows are not traditionally the most efficient, but more recent aluminum windows are more energy efficient than previous designs.

Storm Windows
Storm windows are added to existing windows to increase efficiency. They can be permanent or temporary windows mounted externally or internally to existing windows. Storm windows help protect your glass window panes from damage and weather, and may help your home retain heat and air conditioning in cold or hot weather.

Bay Windows
Bay windows are popular requests in Alameda County because they project outward from the main walls of a home. This creates a larger living space or the illusion of a larger room depending on the type of bay window. Bay windows also add architectural interest and increase the amount of natural light that flows into a room.

Energy Efficient Windows
Energy efficient windows are often designated with an Energy Star label. These windows are known to drastically reduce energy bills. Most energy efficient windows are insulated and protect against heat loss and gain, maintaining indoor air temperature.

Casement Windows
Casement windows are attached to the window frame by side hinges. (Windows that are hinged at the top are called awning windows, while windows attached at the bottom are hopper windows.) Casement windows may contain leaded glass and often open inward. They are often used as venting windows where air circulation is wanted but light and views aren’t as important.

Double-hung Windows
Perhaps the most popular type of window, double-hung windows consist of upper and lower window sashes that slide vertically in side window jambs. They have a maximum opening of one-half the total window area.

Top Requested Brands for New Windows In Alameda County
Many homeowners and window installers in Alameda County have favorite window brands. The most-requested window brands are listed below.

Pella Windows
For more than 85 years, Pella Windows has been making and installing windows. Home window styles available from Pella include casement, awning, double-hung, single-hung, sliding, bay/bow windows and specially-shaped windows that add architectural detail to your home.

Andersen Windows
Andersen Windows is one of the most trusted brands of new windows. Andersen dealers in Alameda County offer replacement windows in a full range of materials and styles.

Marvin Windows
From energy efficient to fully customized designs, Marvin Windows is one of the most recognized window manufacturers. Marvin Authorized Installing Retailers in Alameda County sell and install all types of Marvin Windows.

Champion Windows
Champion Windows is popular for home replacement windows that are custom-made and professionally-installed. They also have Energy Star windows and other energy efficient replacement windows.

Milgard Windows
Vinyl windows, aluminum windows, fiberglass windows and sound control windows for homes and light commercial buildings (such as hospitals and schools) are all available in Alameda County and throughout the greater Bay Area from Milgard Windows.

Simonton Windows
Some window contractors in Alameda County install new construction and replacement windows by Simonton Windows. These include awning windows, double-hung windows, garden windows, casement windows, radius windows, single hung windows and single slider windows.

CertainTeed Windows
All standard and custom home windows are available in Alameda County from CertainTeed Windows. CertainTeed was one of the first window manufacturers to offer vinyl windows. They also offer energy efficient, Low-E glazed windows.

Kolbe Windows
Kolbe Windows and Doors builds and installs new construction windows, replacement windows, historic home windows, custom windows and commercial windows for homes in Alameda County.

PGT Windows
Specially-manufactured PGT Windows are custom impact-resistant windows meant to increase the style, safety and security of your home. Available windows include new construction and replacement windows with aluminum and vinyl frames. PPG also manufactures hurricane windows.

Loewen Windows
Loewen Windows exclusively manufactures wooden windows, including awning windows, casement and double-hung windows, picture windows, access windows, transoms and custom windows. Loewen wooden windows are made from Douglas Fir and Mahogany woods.

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Glossary Of Terms
Glossary of Terms for New Home Windows and Window Contractor Services

Below are terms and descriptions that will help you navigate your way through your replacement window installation from beginning to end.

aluminum windows
Glazed window with aluminum sash and mullions. Aluminum windows are known for strength, value and flexibility in installation configurations to maximize views.

Also known as: aluminum storm windows, aluminum window frames, aluminum replacement windows, aluminum clad windows, aluminum window replacement, aluminum window repair, residential aluminum windows, aluminum frame windows

awning windows
Awning windows have a hinged upper sash that swings outward for ventilation.

Also known as: ventilation windows, awning window replacement, awning replacement windows

bay windows
Bay windows are a unit of three windows, usually made up of a large center fixed window unit and two flanking windows positioned at 30-, 45- or 90-degree angles that project out from the wall. Bay windows may increase the size of a room or may give the appearance of a larger room depending on the construction. Some bay windows have built-in seating and are used as window seats.

Also known as: bow windows, angle bay windows, window seat windows, bay bow windows, bow bay windows, replacement bay windows

casement windows
Windows that are side-hinged or pivoted are known as casement windows. Casement windows have a single sash that cranks outward, to the right or left.

Also known as: crank out windows, casement replacement windows, vinyl casement windows, casement window repair, wood casement windows, steel casement windows, aluminum casement windows, double-hung casement windows, French casement windows, metal casement windows

dormer windows
Dormer windows protrude from the roof of a house. Dormer windows usually include one or more window panes.

Also known as: gable fronted dormer windows, hipped roof dormer windows, flat roof dormer windows, shed dormer windows, wall dormer window, link dormer window, window dormers

double-hung windows
Windows that have two operable sashes which slide vertically in the frame to open and close are known as double-hung windows.

Also known as: sash windows

double glazing windows
Any window made with two thicknesses of glass that are separated by airspace. Double-glazed windows increase energy efficiency and insulate against heat transfer and sound transmission.

Also known as: dual glazing windows, double glazed windows, insulated glazing, insulated glazing windows, double glazing sash windows, double glazed sash windows, energy efficient windows, conservatory windows, Energy Star windows, insulated glass, double-pane windows

dual-action windows
Windows with sashes that open for ventilation and swing open from the top or the side to allow cleaning of the outside glass.

Also known as: sliding windows, swinging windows

Energy Star windows
Energy Star is a government program that established a set of guidelines for energy efficiency. Windows that are Energy Star Qualified meet efficiency requirements and can save seven to 15 percent on home energy bills compared to non-Energy Star windows. Most Energy Star windows are insulated windows or double-paned or triple-paned windows that keep temperature-controlled air in the home and heat or cold out.

Also known as: energy efficient windows, insulated windows, energy efficient vinyl windows, energy efficient window replacements, energy efficient glass windows, energy efficient home windows, energy efficient wood windows

fixed windows
Non-venting or non-operable windows made of fixed glass are referred to as fixed windows. Fixed windows are also known as picture windows and can be reglazed and replaced on-site.

Also known as: picture windows, fixed casement windows, fixed picture windows, fixed vinyl windows

hopper windows
Windows with a top sash that swings inward. Hopper widows are often used in basements and other areas where ventilation is wanted but large windows are not required.

Also known as: casement windows, ventilation windows, basement hopper windows, hopper style windows, vinyl hopper windows

insulating glass
Insulated glass is usually a combination of two or more panes of glass with a sealed air space between the panes that is filled with a harmless gas. This space may be filled with an inert gas, which increases the insulation properties. Most major window companies offer insulated windows as part of their standard catalog.

Also known as: insulated windows, energy efficient windows, Energy Star windows,  insulated glazing, insulated glass, IG, double insulated glass, insulating glass, insulated replacement glass, insulated window glass, insulated glass windows, low-e insulated glass, insulated glass units, window glass insulation

jalousie windows
Windows with a series of overlapping, horizontal louvers that move together are called jalousie windows. Window louver panels open to maximize airflow through the openings.

Also known as: venetian blind windows, shutter windows, blind windows, aluminum jalousie windows, jalousie windows replacement

Window mullions are a vertical structural element that divides window panes and separates side-by-side windows.

Also known as: window divider, window column, aluminum mullions, aluminum window mullions, mullion replacement, replacement mullions, removable mullions, wooden mullions, wood window mullions

picture windows
Non-venting and non-operable windows are generally referred to as picture windows. Also know as fixed windows, picture windows only consist of window frames and glass. Most picture windows are double-paned or insulated to be more energy efficient since they have such a large surface area.

Also known as: fixed windows, non-opening windows, plate glass windows, picture replacement windows, vinyl picture windows

Thermal resistance to the transfer of heat through windows. Windows with higher
R-value have greater insulating properties.

replacement windows
Replacement windows are custom ordered to fit inside the jambs and sill of your existing windows. Replacement windows are usually less expensive to install than installing new windows that require new frames, jambs and window sills.

Also known as: window replacements, vinyl replacement windows, wood replacement windows, aluminum replacement windows, window pane replacements

single glazing
A single pane of glass installed in a window sash. Single-glazed windows are not as energy-efficient as double-glazed windows.

Also known as: conservatory windows, sun room windows,

single-hung windows
Single-hung windows look similar to double-hung windows, except the top sash is fixed and stationary, so only the bottom section opens.

storm windows
Mounted outside or inside the main glass, storm windows are often found in cold climates or as a retrofit of existing windows. Storm windows increase the efficiency of glass windows and can be mounted temporarily or permanently.

Also known as: replacement storm windows, aluminum storm windows, interior storm windows, home storm windows, vinyl storm windows, triple track storm windows, custom storm windows, combination storm windows, exterior storm windows

vinyl windows
Windows made with vinyl, a plastic material, cladding and window units. Vinyl windows are popular because they are relatively inexpensive and maintenance-free.

Also known as: replacement windows, vinyl home windows, vinyl casement windows, maintenance-free windows, vinyl bay windows,

window casing
Also known as window trim, window casing is exposed molding of various widths, thickness and shapes that covers the framework of window and door units.

Also known as: window trim, interior window casing, flexible window casing, decorative window casing, exterior window casing, window interior casing, window molding

window cladding
Cladding is material applied to the outside faces of windows to provide a durable, low-maintenance exterior surface. Cladding often provides protection from the elements and adds an aesthetic touch. It may also be referred to as window capping, which is a specialized field offered by few window contractors.

Also known as: cladded windows, clad windows, vinyl-clad windows

window sash
Window sashes are single frame assemblies of stiles and rails (explain stiles and rails) that hold the glass.

Also known as: window frames, window sashes, window sash repair, double-hung window sash, wood sash windows, antique window sash, window sash replacement

wood windows
Wood windows are those with wooden frames. They are a natural option, so they require more maintenance than vinyl windows, and they must be protected from moisture to avoid warping and rot.

Also known as: wooden windows, wood replacement windows, wood clad windows, custom wood windows, wood casement windows, wood double-hung windows, wood storm windows, aluminum-clad wood windows, exterior wood windows, wood window replacements, historic windows, historic wood windows

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Frequently Asked Questions
Frequently Asked Questions for Local Window Contractors

Q: Why choose a Diamond Certified Window Company?
A: Diamond Certified ends the guessing game by helping you choose a window contractor with confidence by offering a list of top-rated local companies who have passed the country’s most in-depth rating process. Only window companies rated Highest in Quality earn the prestigious Diamond Certified award. Most local window companies can’t pass the ratings. American Ratings Corporation also monitors every Diamond Certified company with in-depth and ongoing research and ratings. And your window installation purchase is backed by the Diamond Certified Performance Guarantee. So you’ll feel confident choosing a Diamond Certified window company for your new windows.

Q: How will replacing my windows improve the comfort of my home?
A: New windows will make your home quieter and more secure. Depending on the windows you choose, you may also notice a marked difference in the temperature of your home as well. Double-paned windows are insulated to keep out the heat of the summer, and maintain heat during the winter.

Q: Will replacing my old windows save me money?
A: Old windows and windows that are improperly installed are the biggest cause of energy loss in the home, costing you money every day. New windows will save you money over the life of the window by cutting heating and cooling costs. Some homeowners report savings of up to 30 percent on their utility bills after installing new windows. New windows can also increase the life of your furnishings and carpeting by keeping out harmful rays of the sun, so you’ll save money by not having to replace expensive furnishings.

Q: If I decide to sell my home, will new windows and doors increase the value?
A: Yes. New windows are one of the best home improvements you can make in terms of the return on your investment. Realtors report that Bay Area homes with new energy-efficient, maintenance-free windows can see return of up to 114% in resale value.

Q: What window materials do I have to choose from?
A: Your choices for new windows are wood, vinyl, steel, aluminum, fiberglass and composite. You’ll see the sash and the frame (the visible outer parts of the window installation units) from the inside and outside of your home, so it’s important to choose the material that gives you the look you want. It’s also important to select the material that has the attributes you’re looking for. For example, metal window frames can conduct heat and cold, so they may not be as energy efficient as wood or vinyl windows. Additionally, some window frame materials can be painted to match your home’s exterior or interior, so that may be an important consideration.

Wood windows can be painted and stained. The downside to wood windows is that they must be regularly maintained. However, most wood windows are made from rot-resistant woods. When maintained correctly, they can last as long as metal windows.

Vinyl windows are inexpensive, energy efficient and durable. And while they cannot be painted, they come in a variety of colors and are virtually maintenance-free.

Steel windows are rarely used in residential buildings, as they aren’t as energy efficient as other types of windows and the window must be painted so they don’t rust.

Aluminum windows are strong and durable. They also allow for greater flexibility in window design. However, they aren’t as energy efficient as other types of windows.

Fiberglass windows are durable, efficient and strong. The frames can be painted to match any home. Because of their quality and durability, fiberglass windows are some of the more expensive widows on the market.

Composite windows have sashes and frames made from more than one type of material. This allows the manufacturer to customize the windows to fit the exact needs of the consumer. Some composite windows have a wood interior that can be painted with more efficient material such as vinyl or aluminum that better resists weather. New composite windows can be made from recycled wood and plastic that can be painted but resist rot.

Q: How do I know which kind of windows are the best choice for me?
A: Your local window contractor will help you decide which manufacturer, style and material of windows is the best fit for your budget, home and aesthetic preferences. It’s wise to make a list of what you’re looking for in new windows so that your window installer can help you decide which windows best fit your needs.

Q: How much do new windows cost?
A: The cost of new windows greatly varies based on the type of windows you select, the manufacturer and the number of windows you have installed. It also depends on whether you’re having replacement windows installed (windows that are custom ordered to fit in place of your existing windows) or whether you’re having new window frames and jambs installed as well. Your window contractor can provide an estimate based on your specific requirements.

Q: How long will it take to install new windows?
A: That depends on the size and scope of your job. A simple window installation may take an hour, while installing new windows throughout an entire home may take several days or a week. Your window contractor should be able to give you an estimated time frame on your specific project.

Q: Can I put in new windows myself?
A: Like with many home improvement projects, you can replace your windows yourself. However, for most window replacement jobs, it’s better to hire a skilled professional. Professional window installers know the best materials and installation techniques for the job. And because they have so much experience removing old windows and installing new ones, they can do the job faster and much more effectively than can most homeowners.

Q: What about getting my new windows from a home improvement store?
A: Most home improvement stores sell new windows, and many advertise low prices. But you may sacrifice selection and quality by getting your new windows from a home improvement store. Most have a smaller selection, so you may not get the windows that best suit your home and your needs. And if they sell discount windows or off-brand products that are less expensive, you run a greater risk that the manufacturer will go out of business, leaving any warranties null and void. Another factor to consider is that most home improvement warehouses don’t provide installation or they rely on subcontractors. That means you can be caught between the retailer, the manufacturer and the installer if there are any problems with your windows.

Q: I’ve heard it’s important to hire a local window contractor that is an authorized installer. What does that mean and why should I look for a certified window installer?
A: Most major window manufacturers certify window contractors whom they have trained to install their specific products. These authorized installers also sell new windows and replacement windows. You’re likely to get a better installation, and some manufacturers even offer extended warranties on products their installers put in. And if something goes wrong later, you can avoid added hassle by hiring the same contractor for the purchase and installation of new windows one company will be responsible for the work.

Q: What happens if someone gets hurt while working on a job on my property?
A: When you hire a legitimate window contractor with the correct license, liability insurance and workers’ compensation insurance, you won’t have to worry. Under workers’ compensation insurance, every employee of the company is covered in the case of accident or injury. You will not be held responsible for damages. Make sure you ask your contractor to show you a copy of their active workers’ compensation policy.

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