How to choose a window installer: 9 questions before you sign

Replacing the windows on a house is one of those big purchases you make only a few times in your life, and almost always with too little information. These are the questions you'd ask an installer if you'd already been through it before.

1. Does the warranty cover the product, the installation, or both?

They're two different warranties and a lot of people find out too late. The manufacturer's warranty covers the glass not fogging and the hardware working. The installation warranty covers the workmanship: that water and air don't come in around the edges.

An installer who only offers you the manufacturer's warranty is telling you, without saying it, that if the problem is their workmanship, they're not responsible.

2. Will you put it in writing?

If the answer is any version of "yes, of course, we always take care of our customers" but nothing arrives on paper, treat it as a no. A warranty that isn't written down doesn't exist.

3. Do you carry liability insurance?

If a worker is injured on your property or something gets broken, you want their insurance covering it, not your homeowner's policy. Ask to see the certificate. An established installer has it on hand and won't be offended that you asked.

4. What happens if you find rotted wood?

This is the expensive surprise in this business. When an old window comes out, rotted wood sometimes appears in the structural frame from years of leaks. It has to be repaired before the new window goes in.

The right question isn't "is it included?" — it almost never is, and that's reasonable, because it can't be seen before opening things up. The question is "how is it priced if it shows up?" You want an agreed price per linear foot up front, not a number improvised with the wall already open.

5. Are the windows made to measure or stock sizes?

Almost no house has perfectly standard openings, especially one that's decades old. A catalog window forced into an opening that doesn't fit gets packed with foam and trim, and that's exactly where air and water get in later.

6. How much deposit do you require?

A deposit is normal, because the windows are made to order and have to be paid for. What is not normal is being asked for most of the total before the material arrives. If someone asks for 100% up front, the conversation ends there.

7. Who does the installation?

Is it company staff or subcontractors? Neither is wrong by itself, but it changes who you go to if something goes wrong. If they subcontract, ask who honors the installation warranty: the company that sold it to you, or the crew.

8. Whose financing is it?

Almost no installer lends its own money — they arrange it with a third-party lender. That's fine. What you need is to see the rate, the term and the monthly payment in writing and from the lender, not a monthly figure recited from memory in your living room.

Watch out for a very low monthly payment: sometimes it hides a very long term. Multiply the monthly payment by the number of months and compare it against the cash price. That math tells you the real cost of the financing.

9. Can I see work you've done nearby?

An installer with years in the area has finished homes a few miles away. This isn't about knocking on anyone's door: photos of real jobs — not catalog shots — and a couple of references are enough.

Red flags

Things worth recognizing in this market:

• "This price is only good today." A window doesn't change price between today and Thursday.

Urgency is a sales technique, not a commercial condition.

• Ads about a "government program" or "windows at no cost." There's no program in Texas today

giving windows to the general public. It's almost always a middleman capturing data to resell.

• "Everyone qualifies" for financing. No lender approves everyone.
• A quote without measuring. A firm price over the phone, without having seen the openings, is

either padded to cover them or going to go up later.

• Pressure to sign on the first visit. A serious estimate can survive you thinking about it

for a week.

The minimum your quote should include

Before signing, check that the paper says:

• window brand and model, and whether the glass has a low-E coating
• frame material
• quantity and measurements per opening
• whether removal and disposal of the old window is included
• total price, and if financed, the rate and the term
• estimated installation date
• product and installation warranty, listed separately
• how rotted-wood repair is charged if it shows up

If anything on this list is missing, ask for it before you sign. A serious installer has no problem putting it in — in fact we prefer it, because then nobody argues later about what was agreed.