Energy-Efficient Windows in Raleigh NC

Why Your Windows Matter More Than You Think

Does one room in your house always feel hotter than the rest? Do you feel a draft by the window in January?

Your windows are often the weakest spot in your home’s shell. Energy Star estimates that air leaks can waste 25 to 40 percent of the energy used to heat and cool a home.

Raleigh summers make this worse. Hot sun pours through old glass for months at a time. Your AC runs longer, and your power bill climbs.

We have installed high-performance windows across the Triangle since 1986. Today, we offer two upgrades that go well beyond a basic double-pane window: the Ascent series with Advanced Thin Triple Pane Glass and Heat Mirror windows.

What Is the Ascent Thin Triple Pane Window?

The Ascent is a vinyl replacement window made by Kensington High Performance Products. Its big feature is a new kind of triple-pane glass.

Regular triple-pane windows insulate well, but they come with trade-offs:

• They are heavy. That makes them harder to open and wears out the parts faster.
• They are darker. The extra layer of glass blocks more daylight.

The Ascent fixes both problems. It uses an ultra-thin center pane, so you get triple-pane insulation in a lighter, brighter window.

Source: Kensington HPP Ascent brochure. Seal life is based on chamber testing that simulates 80 years.

How Airtight Is It?

Great glass does not help much if air leaks around the frame. This is where the Ascent really stands out.

In a test with a steady 25 mph wind, the Ascent let in just 0.03 cubic feet of air per square foot each minute. Here is how that compares:

• It takes 5 Ascent windows to let in as much air as 1 typical vinyl window.
• It takes 8 Ascent windows to let in as much air as 1 wood clad window.

Less air leaking in means fewer drafts, less dust and pollen, and steadier temperatures from room to room.

What Else Is Built Into the Ascent?

• Foam-filled frame and sashes: Insulating foam fills the hollow parts of the frame. This cuts heat loss and reduces condensation.
• Warm-edge TPS spacer: The spacer between the panes bonds to the glass. It holds in the argon gas and resists seal failure.
• UV-resistant vinyl: The vinyl is made to stand up to strong sun, and it is phthalate free.
• Welded corners: Each corner is heat-fused for a permanent seal.
• Slim frame: About 20% more glass area than other vinyl windows, so you see more of the view.
• Anti-microbial weatherstripping: Helps block dust and allergens and resists mold and mildew.

How the Ascent Handles a Raleigh Summer

In the Triangle, we spend far more money cooling our homes than heating them. So the number that matters most here is how well a window blocks the sun’s heat.

That number is called the Solar Heat Gain Coefficient, or SHGC. Lower is better in a hot climate. New to these terms? Our guide to Low-E glass explains them in plain English.

NFRC ratings for a double-hung window with no grids and double-strength glass. Ratings vary by size and style.

An SHGC of 0.19 means the glass blocks most of the sun’s heat. That is a big help on west-facing windows that bake every afternoon from May through September.

What Are Heat Mirror Windows?

Heat Mirror is another high-performance glass option we install through Kensington. It is a brand of insulating glass from Eastman.

A standard double-pane window has two sheets of glass with a gap in between. Heat Mirror adds a thin, clear film stretched inside that gap. The film reflects heat and blocks UV rays without adding the weight of another glass pane.

Which is right for you? Both beat a basic double-pane window by a wide margin. During your estimate, we will compare them for your home, your budget, and how you use each room.

Comparing Your Glass Options

Want to see how the glass choice affects your total price? Read our guide to window replacement cost in Raleigh.

Signs Your Windows Are Costing You Money

Not sure if it is time to upgrade? Look for these signs:

• Drafts you can feel near the window on a cold or windy day
• Fog or moisture trapped between the panes
• Rooms that stay hot all summer, even with the AC running
• Furniture or floors fading near sunny windows
• Windows that stick, rattle, or will not stay open
• Power bills that keep rising without a change in your habits

Two or more of these? New energy-efficient windows will likely make a real difference in your comfort. Seeing water on the glass? Learn what condensation on the inside of windows means.

Backed by a Lifetime Warranty

The Ascent comes with a warranty built for the long haul:

• Lifetime, non-prorated coverage
• Lifetime, no-fault glass breakage coverage
• Transferable to the next owner if you sell your home

A transferable warranty can also be a selling point when you list your home.

What Homeowners Say About Their New Windows

“Beautiful, energy-efficient windows. Noticeably quieter indoors. Harland worked with us on product choices, very flexible. Best contractor I’ve worked with.”

Sam J., Fuquay-Varina, NC

“Excellent communicator, timely responses, high-quality windows, improved home comfort.”

Homeowner, Wake Forest, NC

Custom Made and Installed by Our Own Team

Every window we install is custom made to fit your openings. We do not force standard sizes into your walls.

Here is how it works:

1. Send us a few photos of your current windows.
2. We visit to measure each opening.
3. You get a clear, written proposal.
4. We order your windows. Most jobs start 3 to 4 weeks after you book.
5. Our crew installs and cleans up every day.

We install energy-efficient windows in every style, including double-hung, sliding, casement, picture, and bay and bow windows. See our main Raleigh window replacement and installation page for the full service.

Frequently Asked Questions

Are triple-pane windows worth it in Raleigh?

For most Raleigh homes, yes. Triple-pane windows with low solar heat gain block summer heat, cut drafts, and quiet outside noise. The Ascent’s thin center pane also avoids the weight and dark tint of older triple-pane windows.

What is the difference between Heat Mirror and triple-pane windows?

Heat Mirror uses a thin film suspended between two panes of glass. Triple pane uses a third sheet of glass. Both insulate far better than standard double pane. We will help you choose based on your home and budget.

Will energy-efficient windows lower my power bill?

They can, especially if your current windows are old, single pane, or leaky. Savings depend on your home, your HVAC, and how many windows you replace. Most homeowners also notice the comfort difference right away.

Do triple-pane windows make rooms darker?

Older triple-pane windows can. The Ascent lets in 35% more visible light than standard triple pane because of its thin center pane.

How long does installation take?

Most homes take one to two days once the windows arrive. Larger whole-house jobs may take a little longer. Your proposal will include a timeline.

Do you offer financing?

Yes. We offer financing options to help fit new windows into your budget. We can go over the details during your free estimate.

Get a Free Energy-Efficient Window Estimate

Ready for a cooler, quieter, more comfortable home? We serve Raleigh, Garner, Cary, Durham, Wake Forest, and the rest of the Triangle.

Call (919) 851-0060 or request your free estimate online.

About the Owner
Harland Johnson is the owner of Harland Windows & Siding. He has run the company for over 40 years and has personally overseen window, siding, and sunroom projects throughout Wake County and the Triangle. Harland Windows & Siding is an A+ rated, BBB accredited business.