Most homeowners spend more time researching a new appliance than they do vetting a window replacement contractor. That is understandable. Windows are not something most people shop for often, and it is hard to know what you do not know.
The questions below are the ones worth asking before you commit. Some are about the product. Others are about the company. All of them will tell you something useful.
Full-frame or insert: which one are you quoting me?
This distinction significantly changes the project’s scope, and not every contractor explains it up front. A full-frame replacement removes the window down to the rough opening in the wall. An insert replacement fits a new window into your existing frame.
Insert installations are faster and less disruptive, but they only make sense when the existing frame is in good condition. If there is rot, water damage, or the frames are out of square, inserting a new window into a compromised frame is not a fix. Ask which approach is being proposed and what the reasoning is.
What is the window made of, and how does that material hold up over time?
Frame material affects how the window performs in cold winters and humid summers, how often it needs maintenance, and how long it actually lasts. Vinyl is common and affordable, but it can expand and contract significantly with temperature changes. Wood looks great but requires upkeep. Aluminum is durable but not a strong insulator.
Renewal by Andersen uses Fibrex, a composite of wood fiber and thermoplastic polymer. It is stronger and more stable than vinyl and requires less maintenance than wood. Whatever material a contractor quotes you, ask how it performs in your specific climate and what its expected lifespan is.
Can you walk me through the U-factor and SHGC on these windows?
If a salesperson cannot explain these two numbers, that is worth knowing. U-factor measures how much heat the window lets escape, with lower numbers indicating better insulation. Solar Heat Gain Coefficient (SHGC) measures how much heat from sunlight passes through the glass.
For Wisconsin homeowners, a low U-factor is a priority because of how hard the heating season is on older windows. ENERGY STAR certification is a baseline to look for, but ask specifically which climate zone the windows are rated for.
Are your installers employees or subcontractors?
Window quality only goes so far if the installation is sloppy. Gaps in the flashing, improper sealing, and frames set out of level are all installation problems that show up later as drafts, condensation, or water damage.
Companies that use their own trained crews tend to have more consistent results than those that hand the job off to whoever is available. At Renewal by Andersen, our installers are part of our team, not a third-party crew brought in for the job. Ask any contractor you are considering how long their installers have been doing this work and whether they are on staff.
What exactly does the warranty cover?
Read the warranty, or at minimum ask someone to explain it to you plainly. Key things to understand:
- Does it cover installation defects or just the window itself?
- How long does coverage last, and does it change after a certain number of years?
- Does the warranty transfer to a new owner if you sell?
- Who do you call to use it, and how does that process actually work?
A product warranty that does not cover the labor to fix a problem is not as useful as it sounds. Make sure you know what you are actually getting.
What will the installation day look like?
Ask for specifics. How early does the crew arrive? How many windows will they complete in one visit? Will your home be open to outside air while windows are being swapped out, and for how long? What do they do to protect your floors and furniture?
For homes with a lot of windows or with older construction, there can be surprises once the original windows come out. Ask how the company handles unexpected findings and whether that affects the final price.
What is and is not included in this quote?
Window quotes are not always as complete as they look. Before you compare bids, find out:
- Is haul-away of the old windows included?
- Does the price cover trim work on the interior and exterior?
- Are permits included if your city or county requires them?
- Is there an additional charge if the crew finds rot or damage behind the existing frame?
Getting this in writing before work begins protects you from a final invoice that looks different from the number you agreed to.
How much maintenance will these windows need going forward?
Some windows need periodic sealing or repainting to stay in good shape. Others need almost no attention beyond cleaning. Ask the contractor what the manufacturer recommends for ongoing maintenance and whether that changes depending on your home’s sun exposure or climate conditions.
If low maintenance was part of why you decided to replace your windows, make sure the product you are buying actually delivers on that.
Do you have references or local project photos?
Online reviews are a starting point, but references from homeowners in your area carry more weight. A company doing good work in your market should have no trouble coming up with names. Photos of completed local projects are also useful, especially if your home has older construction or less common window configurations.
How do I reach you after the job is done?
Before installation day, confirm who you call if you notice something off in the weeks following the project. Is there a dedicated service line? A specific person to contact? A clear process for warranty work?
Companies that handle post-install service well usually have a clear answer to this question. Those that do not tend to be harder to reach once the check clears.
Get Your Questions Answered in Person
The questions to ask before a window replacement are easier to work through with someone who knows your home. A walkthrough gives you a lot more information than a phone estimate.
Renewal by Andersen offers free in-home consultations with no obligation. Schedule one and get straight answers about what your windows actually need.
