- Windows
- Energy Efficiency
The Real Cost of Old Windows: How Your Energy Bills Reveal Window Problems
Your August electric bill is a diagnostic tool. Here is how to read it, what old windows actually cost you, and the honest math on whether new ones pay.
Your August electric bill is the most honest home inspector you will ever hire. In a Tulsa summer, cooling is the biggest line on that bill, and old windows are one of the biggest reasons the AC cannot keep up. If your bill spikes hard every July and August, certain rooms are unusable by afternoon, and the AC seems to run without ever cycling off, your windows are prime suspects. The fix is not always replacement, and we will be straight with you about when it is not, but the first step is reading the evidence your house is already giving you.
We install windows across Tulsa, Broken Arrow, Owasso, Jenks, and the rest of Northeastern Oklahoma, and August is when the phone rings with some version of the same sentence: “our electric bill just hit an all-time high and the upstairs is still miserable.” Here is how we diagnose it, and the honest math behind the decision.
The August Bill Test: Signs Your Windows Are the Problem
You do not need instruments to run this test. You need your last two electric bills and ten minutes of walking your house on a hot afternoon.
- The AC never cycles off. On a 100 degree day, even a healthy system runs long. But if it runs continuously from 2 pm to 8 pm and the house still will not hold temperature, heat is entering faster than the system can remove it, and glass is usually the biggest entry point.
- Rooms facing west or south are noticeably hotter. Stand in them at 4 pm. If one room runs 5 degrees hotter than the hallway, the sun is winning through that glass.
- The glass itself is hot to the touch from inside. Modern Low-E glass rejects a large share of solar heat. Old clear glass hands it straight into the room. Hot interior glass in the afternoon is old glass doing exactly what it was built to do in 1985.
- Curtains move when the wind blows. Air leaks that chill you in January also let your cooled air escape in August. A leak is a leak in both seasons.
- Fog or haze trapped between the panes. That is a failed seal. The insulating gas is gone, and that window is now performing close to a single-pane unit no matter how good it looks from the curb.
Why Old Windows Run Up a Tulsa Bill
Four things make an old window expensive to live behind, and most older Tulsa-area homes have at least two of them.
Single-pane glass has no insulating layer at all. It is a thermal hole in the wall, roughly the difference between a winter coat and a t-shirt. Homes built before the 1980s around Tulsa often still carry original single-pane units, and they are the single biggest energy upgrade opportunity in the house.
Failed seals on double-pane glass. Insulated glass is only insulated while the seal holds. Seals age out, the argon escapes, and the fog shows up later. A 20 year old double-pane window with dead seals performs far closer to single-pane than homeowners expect, which is why “are 20 year old windows still efficient” almost always answers itself.
Old aluminum frames. Aluminum conducts heat beautifully, which is exactly what you do not want wrapped around your glass. On an August afternoon an unbroken aluminum frame is a radiator pointed into your living room. Many 1970s and 1980s Broken Arrow and Sand Springs homes still have them.
Plain clear glass with no coating. The Solar Heat Gain Coefficient, the rating for how much solar heat passes through, is the number that matters most in our climate. Old clear glass lets most of that heat in. Modern Low-E coatings reject a large share of it before it ever enters the room, which we cover in depth in our guide to energy-efficient windows for Oklahoma summers.
| Window Problem | What You Notice at Home | The Fix | Installed Cost |
|---|---|---|---|
| Single-pane glass | Hot glass, huge summer bills, cold winter rooms | Full replacement with double-pane Low-E | $700 to $1,100 per window |
| Failed seal on double-pane | Fog between panes, performance quietly declining | Glass-only replacement | $500 to $750 per opening |
| Air leaks around sash or frame | Moving curtains, dust lines, drafts both seasons | Sealing and weatherstripping, or replacement if the sash is racked | DIY cheap; replacement if structural |
| Old aluminum frames | Frame hot to the touch, condensation in winter | Full replacement with vinyl or composite frames | $700 to $1,100 per window |
| Clear glass on west or south exposure | One room unusable by 4 pm | Low-E replacement glass prioritized on those walls | Start with the worst 3 to 5 windows |
The Honest Math on Replacement
Here is the part a lot of window companies fudge, so let us not. ENERGY STAR’s data on certified windows shows the biggest savings come from replacing single-pane windows, with more modest savings when replacing old double-pane units. New windows will lower a Tulsa cooling bill, and over years the savings are real money. But if someone sells you windows purely on the promise that the energy savings pay for the project quickly, be skeptical of everything else they say.
What the spreadsheet misses is what you actually feel. The week after a whole-house replacement, the upstairs stops being a sauna, the AC starts cycling again instead of grinding until sunset, and the west-facing bedroom becomes usable at 4 pm in August. Less runtime also means less wear on your HVAC, which in Oklahoma summers is not a small thing.
Our installed pricing for window replacement is $700 to $1,100 per window depending on size and product. For a typical 15 window home that is $10,500 to $16,500 whole-house, backed by our 5-year workmanship warranty, and financing is available for qualifying projects. If you are weighing double-pane against an upgrade to triple-pane, our double-pane vs triple-pane comparison gives you the honest Oklahoma answer, which is that triple rarely pays here.
Before You Replace: What Actually Helps Old Windows
Not every high bill ends in a window order, and we would rather tell you that now. If your windows are structurally sound and double-pane with living seals, cheaper moves come first: lock every sash so the weatherstrip compresses, seal the exterior frame joints, and put cellular shades or decent curtains on the worst sun-facing glass. Those cost little and help both seasons.
If a seal has failed but the window is otherwise good, a glass-only replacement at $500 to $750 per opening restores the insulating layer without buying a whole window. We do these regularly and will recommend one when it is the right call.
What no amount of sealing fixes: single-pane glass, conductive aluminum frames, and sashes racked out of square by decades of Oklahoma’s expanding clay soil. Those are the windows where replacement stops being an upgrade and starts being the repair.
Get a Straight Answer About Your Bill
Bring us your worst August bill and we will walk the house with you: which windows are actually driving it, which need a $10 fix, which need glass, and which need replacing. That is the whole conversation, no franchise script, and the estimate is free. Call Morgan Windows at (918) 400-2326 or request a free in-home estimate. Locally owned, serving Tulsa, Broken Arrow, Owasso, Jenks, Bixby, Sand Springs, Catoosa, and Claremore, with every installation backed by our 5-year workmanship warranty.