A window installer is the crew that removes your old windows and sets the new ones, and their work decides whether a good window performs well. Hire one by checking four things: what they say about your opening, their paperwork, a written scope and how they handle problems after the job.
The short answer
- A careful installer measures each opening and checks for soft wood before talking about a total.
- Ask for proof of insurance, written warranty terms and a written scope with sizes for each opening.
- A badge or membership is a reason to ask more questions, not the end of them.
- Pressure to sign the same day and a vague scope are the two warning signs that matter most.
- Make sure one named company answers for the whole job, whoever does the work on the day.
- On a house built before 1978, ask whether the firm is EPA Lead-Safe Certified.
The estimate visit is a job interview, and you are the one asking the questions. In 2026 a homeowner has more ways than ever to compare windows online. The installer is the part you cannot compare on a screen. This post shows you what to watch for, in the order it usually happens.
What should a window installer do at the estimate visit?
A careful installer looks at your walls before talking about windows. They measure each opening, check the sills and trim for soft spots, ask what bothers you about the old windows, and note which way each wall faces. If someone gives you a total after one measurement and five minutes, they are guessing.
- They measure more than one window, and they measure each opening in more than one place.
- They press on the sill and the trim to check for soft wood.
- They ask about drafts, noise, glare and the rooms that run hot.
- They explain how water will be kept out at the sill and the head of the window.
- They tell you what they cannot see yet, such as rot behind the trim.
Local ground matters here. A Fort Worth house sits on thin soil over limestone, and many Dallas and Plano houses sit on clay that swells and shrinks. The two can move differently over the years. Ask the installer what they check for in an opening on your kind of ground, and listen for a real answer, not a slogan.
Which paperwork should you ask a window installer for?
Ask for proof of insurance, the written warranty terms, any manufacturer certification, and a written scope of work. Reading these takes a few minutes. They tell you who is responsible if something goes wrong, which is something a friendly visit cannot tell you.
| Ask for | Why it matters | What a good answer looks like |
|---|---|---|
| Certificate of insurance | It shows who pays if something is damaged or someone is hurt on your property | A readable certificate with the insurer’s name and dates |
| Written warranty terms | The product and the labor are often covered by different parties | Separate sections for each, with the exclusions listed |
| Manufacturer certification | Some brands tie their warranty to approved installers | A named program you can confirm with the manufacturer |
| Lead-safe certification | Houses built before 1978 may have lead paint on old frames | EPA Lead-Safe Certified Firm status |
| Written scope | It fixes the series, glass, count and extras that the total covers | A line for each opening, with sizes |
To check a warranty claim, go to the source. The Andersen website is where you can read what its product warranty expects from the installer. American Eagle Builders installs Andersen windows, and we are an EPA Lead-Safe Certified Firm, so those are two questions we expect to be asked.
Who actually does the work, and who answers for it?
Ask who will be on your roof and in your rooms, and who you call if a window needs adjusting later. Companies set up crews in different ways, and more than one setup can work well. What matters is that one company stands behind the whole job and you know its name.
Ask one more thing: will the same person who did your estimate be there on install day, or at least have written down what they saw? Details get lost between a sales visit and a crew arriving. A written scope with sizes and notes on each opening closes that gap.
What do credentials tell you, and what do they not?
They tell you a company has met a specific standard or joined a trade group. They do not guarantee any single job. Treat a badge as a reason to ask more, not as the end of the questions. Texas does not run one general state license for remodelers, so check what your city asks of contractors.
Two credentials worth knowing are the EPA’s Lead-Safe program, which covers work on older paint, and membership in a trade group such as NARI, the remodelers' association. American Eagle Builders is listed with both. Ask any firm you are considering which groups it belongs to and what those groups require.
What are the warning signs when hiring a window installer?
Pressure and vagueness are the two big ones. If someone insists you sign the same day, or will not write the scope down, take that as your answer. A company that is sure of its work can wait a few days while you compare.
- A price that is good “only if you sign today.”
- A scope that says “replace windows” without a list of openings and sizes.
- No written warranty, or one that will not say what it excludes.
- A request for the whole payment before any work starts.
- No office address, or no one who will give you a company name to look up.
If a business treats you badly, the Texas Attorney General’s consumer protection office takes complaints. It is better to avoid the problem. Our posts on questions to ask a renovation contractor before signing and how to avoid contractor scams give you more to check.
What is a sensible next step?
Get two or three written estimates for the same windows and compare them line by line. Then read how each company describes the install. Our post on window installation quality in DFW describes the work you should expect on install day. You can see the windows we install on our windows page, learn more about our family company, or ask for a free in-home estimate.
Questions we get asked about this
Watch how they handle the estimate visit. A careful installer measures each opening, checks the sills for soft spots and explains how water will be kept out. Then ask for proof of insurance, written warranty terms and a written scope. Compare two or three companies on those points, not just the total.
It helps, because some manufacturers tie their warranty to approved installers. Ask which program the company belongs to, then confirm it with the manufacturer. A certification is a reason to ask more questions. It does not replace a written scope and clear warranty terms.
Not always. Some companies sell windows and install them with their own crews, and some sell and then hand the work to others. Either can work well. Make sure one company is named on the contract and answers for the whole job.
A written scope with each opening and size, the series and glass for each window, warranty terms for product and labor, and proof of insurance. If your house was built before 1978, ask whether the firm is lead-safe certified. Keep copies in one folder.
Yes, and we would like you to ask them. American Eagle Builders is a family company in Arlington, and we are an EPA Lead-Safe Certified Firm and install Andersen windows. Our estimates are free, in your home, and we write down what we find.
