Do Impact Windows
Save Energy?
Palm Beach County
Yes — but only the right ones, and only if they're installed right. "Impact-rated" and "energy-efficient" are two different certifications measuring two different things, and plenty of Palm Beach County homeowners have bought hurricane glass and watched the electric bill barely move. Here's what actually decides whether new windows lower your bill, written by a licensed general contractor (CGC1528750) who is also a RESNET® Certified HERS Rater — RTIN 4516301 and can measure the difference instead of promising it.
The Short Answer
An impact window earns its rating by surviving a nine-pound two-by-four fired at it and then thousands of pressure cycles. That test says nothing about heat. Two windows can carry the same Florida Product Approval or Miami-Dade Notice of Acceptance and perform completely differently on your power bill, because the energy performance comes from a separate set of features: the low-E coating, whether the unit is insulated (two lites with a sealed airspace) or a single laminated pane, the frame and its thermal break, and the quality of the installation seal around the opening.
So the honest version of the answer is this. Replacing tired single-pane glass with well-specified insulated, low-E impact units almost always reduces cooling load in South Florida — glass is where the sun gets in, and here the sun is the load. How much you save depends on how much of your home's heat gain is coming through the windows in the first place, and that is a measurable number, not a guess. That's the whole point of having the estimate done by a certified energy rater: you find out where your house is actually losing before you spend on glass.
Ready for the measured version? Call (561) 779-3213 — the wind-mitigation and energy walk-through is free with any window or roofing estimate.
Impact Rating vs. Energy Rating — Two Different Labels
Every window we install carries both kinds of paperwork, and it's worth knowing which document tells you what. Confusing the two is the single most common reason a homeowner is disappointed by an expensive window purchase.
The Storm Paperwork
Florida Product Approval or a Miami-Dade Notice of Acceptance (NOA) proves the unit passed missile-impact and cyclic-pressure testing for our wind zone. This is what makes it opening protection for the building code and for your insurer — and it says nothing at all about heat, glare, or your electric bill.
The Energy Paperwork
The NFRC label — the sticker on the glass — carries the thermal performance certified by the National Fenestration Rating Council. This is the document that tells you whether the window will lower your cooling load. Ask for it by name on every quote, and compare it line for line between bids.
How to Read the NFRC Label — Florida Edition
The label lists up to five numbers. In a heating climate the top one matters most; in Palm Beach County the order is almost reversed, because our problem is keeping the sun out, not keeping a furnace's warmth in. Here's how to weigh them where we live.
1 · SHGC — read this first
Solar Heat Gain Coefficient: the share of the sun's heat that gets through, from 0 to 1. Lower is cooler. This is the number that moves a Florida cooling bill, and it's the one the U.S. Department of Energy singles out for hot climates — its guidance is 0.25 or lower. Florida's energy code takes the same view: for our Climate Zone 1 the prescriptive table caps glazed fenestration SHGC at 0.25 while treating U-factor far more loosely.
2 · Air Leakage
How much air passes through the assembly, in cubic feet per minute per square foot. Lower is tighter. In a humid climate, leaked air brings humidity with it, and humidity is half of what your air conditioner is paid to remove. A tight unit is quieter and less dusty too.
3 · U-Factor
The rate of straight heat conduction through the window; lower insulates better. It matters here — an aluminum frame in August conducts real heat inward — but in Climate Zone 1 it is the junior partner to SHGC. Don't let a salesperson sell you on U-factor alone.
4 · Visible Transmittance
How much daylight comes through, 0 to 1. Higher is brighter. This is the trade-off number: modern spectrally selective low-E coatings block infrared heat while letting visible light pass, so you can get a low SHGC without living in a cave. Compare VT alongside SHGC and you'll see which products manage that trick well.
5 · Condensation Resistance
An optional 1–100 rating; higher resists condensation better. Less critical in our climate than up north, but a useful tie-breaker if you keep the house cold and run into sweating glass on muggy mornings.
The ENERGY STAR shortcut
ENERGY STAR sets its window criteria by climate zone, and Florida sits in the Southern zone — the strictest on solar heat gain. If a unit is certified for the Southern zone, someone has already done the label math for our climate. Verify the zone on the label, not just the logo.
The Four Things That Decide Your Savings
Once you know which numbers to read, the specification conversation gets simple. Four choices account for nearly all of the difference between impact windows that lower a bill and impact windows that just sit there looking strong.
- 🪟 The glass package. Clear laminated glass with no coating is the entry point — strong, but a poor solar filter. A spectrally selective low-E coating is the upgrade that does the real work: a microscopically thin metallic layer that reflects infrared heat back outside while passing daylight. On the same window, the coating choice can be the difference between a high SHGC and one comfortably inside Florida's target.
- 🧊 Single laminated pane vs. insulated unit. A monolithic laminated impact window is two lites bonded to one interlayer — one solid piece of glass. An insulated impact unit adds a second lite and a sealed airspace, which is what buys you the lower U-factor and the warmer interior surface. Both can be impact-rated; only one is insulating.
- 🖼️ Frame and thermal break. Bare aluminum conducts heat well — which is exactly what you don't want in a window frame. Thermally broken aluminum and vinyl frames interrupt that path, and the spacer holding an insulated unit together matters for the same reason. Frame choice also drives how the unit looks and how narrow the sightlines can be, so it's worth deciding on purpose.
- 🔧 The installation. This is the one no label covers. The NFRC numbers describe the unit in a laboratory; they say nothing about the gap between your new frame and the wall. Anchored to NOA specification, properly flashed, and sealed at the buck, that gap is closed. Done fast and cheap, it becomes a permanent air leak behind the trim — and your expensive glass underperforms its own sticker. Licensed, permitted, inspected installation is an energy decision, not just a paperwork one.
We install CGI, PGT WinGuard, ES, and Monogram lines — with impact windows starting from $150 — and we'll walk the glass packages with you against your own home's exposures rather than pushing one spec at every wall. See the full service on the Impact Windows & Doors page ↗.
Why We Won't Quote You a Percentage
Search "impact windows energy savings" and you'll be handed confident percentages. We don't give those, and you should be a little suspicious of anyone who does before they've seen your house. The savings from new glass depend on how many square feet of window you have, which direction they face, what shades them, how leaky the rest of the envelope is, how much of your duct run sits in a hot attic, and what you set the thermostat to. A west-facing wall of uncovered single-pane glass and a small, shaded north window are not the same project.
What a certified rater can do is measure. A blower-door test quantifies how leaky the house is. A walk-through documents glazing area, orientation, shading, insulation levels, and duct condition. From that we can tell you where your load is actually coming from and which fix returns the most per dollar — sometimes that's windows, sometimes it's the attic you've never been in. Read what the process involves in our home energy audit guide ↗.
Florida code requires that this kind of testing be performed by a certified rater. The owner is one — RESNET® Florida Class 1 Energy Rater, listed in the State of Florida's certified-rater registry (verify in the state rater registry ↗) — and also the licensed general contractor who does the work. That combination is why the numbers here stay honest.
Where Glass Belongs in the Priority Order
Here's the advice a window-only company can't afford to give you: in a lot of Palm Beach County homes, windows are not the cheapest first move for energy alone. Attic air sealing and insulation usually return more per dollar, and leaky ducts running through a 130°F attic can waste cooling you already paid to produce. If your only goal were a lower bill, that's often where we'd start — and we'd tell you so.
What changes the math for glass is that windows do four jobs at once. They cut solar heat gain, they harden the openings for hurricane season, they can earn homeowners-insurance wind-mitigation credits, and they end the shutter ritual forever. Judge them on all four and impact windows are frequently the best-value project on the house — just don't buy them expecting the attic's savings.
The full priority order for a South Florida home is laid out on the Energy-Efficient Home Improvement hub ↗, and the free-first version — habits before hardware — is in the summer cooling-cost checklist ↗. If solar is on your horizon, cut the load before you size the array: see the solar-readiness checklist ↗. It's the same sequence behind the owner's own 1974 West Palm Beach home, where integrated efficiency measures brought demand down far enough that an 8kW solar array meets the needs of a seven-resident household.
The Benefits That Never Show Up on the Power Bill
🛡️
Insurance Credits
Documented opening protection is credited on the wind-mitigation form your insurer uses. Generally every glazed opening has to be protected to earn the full credit — see the
insurance discount guide ↗.
🔇
Quiet
The same laminated interlayer that holds glass together after an impact also damps sound. Homeowners on busy roads often notice the quiet before they notice the bill.
🌈
Less Fading
Laminated glass blocks the great majority of ultraviolet light, and low-E coatings cut it further — which spares floors, art, and upholstery the bleaching that Florida sun delivers through clear single-pane glass.
💧
Drier Air
A tight window keeps humid outside air outside. Less moisture sneaking in means the air conditioner spends less of its capacity wringing out water and more of it cooling you.
☀️
No More Hot Rooms
The west-facing room nobody can sit in after 3 p.m. is a solar-gain problem. Low-E glass on that wall is usually the fix — the comfort gain people feel most immediately.
🏷️
Resale
Permits, product approvals, and NFRC labels in a folder are a selling point in South Florida. Buyers ask; missing paperwork becomes a negotiation.
🌿Financing available through our partner Renew Financial's RenewPACE program — designed for energy and storm-protection upgrades like impact windows and new roofs. Ask us about eligibility.
🎁Free wind-mitigation & energy walk-through with every roofing or window estimate. We'll read your existing glass, measure where the heat is getting in, and show you both the insurance credits and the comfort gains before you spend a dollar — backed by a written one-year workmanship warranty. The only Palm Beach County contractor who is also a certified energy engineer — the owner inspects every job.
Impact Windows & Energy Savings — FAQ
Do impact windows save energy?
Well-specified ones do. Replacing old single-pane glass with insulated, low-E impact units reduces the solar heat coming into the house and the conditioned air leaking out of it, so the air conditioner runs less. But the saving comes from the energy features — the low-E coating, the insulated glass unit, the frame's thermal break, and a properly sealed installation — not from the impact rating itself. An impact window with clear, uncoated glass is strong and still lets a lot of Florida heat through.
Are all impact windows energy efficient?
No, and this is the most useful thing to know before you shop. Impact approval and energy performance are certified separately: Florida Product Approval or a Miami-Dade NOA covers missile impact and wind pressure, while the NFRC label covers thermal performance. Two windows with identical storm ratings can perform very differently on your bill. Ask for the NFRC numbers on every quote and compare them line for line.
What SHGC should I look for in Palm Beach County?
Solar Heat Gain Coefficient is the number to read first in Florida, and lower is cooler. The U.S. Department of Energy's guidance for hot climates is 0.25 or lower, and Florida's energy code takes the same position for our Climate Zone 1, where the prescriptive table caps glazed fenestration SHGC at 0.25 while treating U-factor much more loosely. Because code editions change, we confirm the current requirement against the edition your permit falls under when we scope the job.
What's the difference between laminated and insulated impact glass?
A monolithic laminated impact window is two lites bonded to a tough interlayer, forming one solid piece of glass — that's what gives it impact resistance. An insulated impact unit adds a second lite and a sealed airspace, which is what actually slows heat conduction and lowers the U-factor. Both can be hurricane-rated; only the insulated version insulates. In a cooling climate the low-E coating still does the heaviest lifting, so the best answer is usually insulated glass with a spectrally selective coating.
How much will new impact windows lower my electric bill?
We won't quote a percentage before we've seen the house, and we'd gently question anyone who does. It depends on how much glass you have, which way it faces, what shades it, how leaky the rest of the envelope is, whether your ducts run through a hot attic, and how you set the thermostat. What we can do is measure: a blower-door test and an energy walk-through show where your cooling load is really coming from, so the estimate reflects your home instead of an average.
Will low-E or tinted glass make my house dark?
Not with modern glass. Spectrally selective low-E coatings are designed to reflect infrared heat while letting visible light through, which is why you should read Visible Transmittance next to SHGC on the label — high VT with low SHGC means bright rooms and less heat. Tint is a separate choice that darkens the view and can help with glare on a harsh exposure. We'll show you the options against your own rooms so you're choosing daylight and heat deliberately, not by accident.
Does the installation affect energy performance?
Enormously, and no label captures it. The NFRC numbers describe the unit in a lab; they say nothing about the gap between your new frame and the wall. Anchored to the manufacturer's Notice of Acceptance specification, properly flashed, and sealed at the buck, that gap is closed and the window performs like its sticker. Rushed, unsealed, or unpermitted, it becomes a permanent air leak hidden behind the trim. We pull the permit under CGC1528750 and carry the job through county inspection.
Should I do windows or attic insulation first?
If your only goal is a lower bill, attic air sealing and insulation often return more per dollar than glass in a South Florida home, and leaky ducts in a hot attic can be costlier still. What tips the scales toward windows is that they do four jobs at once: cut solar heat gain, protect the openings in a storm, earn insurance wind-mitigation credits, and retire the shutters for good. Judged on all four, impact windows are frequently the best-value project on the house — an energy assessment tells you the right order for yours.
Do energy-efficient impact windows also lower my insurance?
The storm rating is what earns insurance credit, not the energy rating — but the same window carries both. Florida requires insurers to credit approved hurricane opening protection, documented through a wind mitigation inspection, and generally every glazed opening must be protected to earn the largest credit. That's the double return on one project: a cooler house and a smaller wind premium. Our Impact Window Insurance Discount Guide walks through exactly what the inspector looks for.
Is financing available for energy-efficient impact windows?
Financing for energy and storm-protection upgrades like impact windows and new roofs is available through our partner Renew Financial's RenewPACE program — ask us about eligibility. Efficiency incentive programs also come and go, so instead of naming one that may be stale we tell you what's active when we scope your project and suggest confirming any tax treatment with your own professional. We never quote rates, payments, or approvals.
Do you serve my area?
Yes. Based in Loxahatchee at 16140 Okeechobee Blvd, we install impact windows and doors and perform energy assessments throughout Palm Beach County — West Palm Beach, Loxahatchee, The Acreage, Wellington, Royal Palm Beach, Jupiter, Palm Beach Gardens, Boynton Beach, and the surrounding communities. As a state-certified energy rater the owner also serves Broward, Miami-Dade, Martin, St. Lucie, Okeechobee, and Indian River counties. Call (561) 779-3213.