Your exterior doors do more than welcome guests—they’re basically the gatekeepers of your home. If they’re old, drafty, or just not pulling their weight, you might as well be throwing money out with every breeze.
Investing in the best energy-efficient exterior doors can keep your home comfy, your energy bills lower, and your carbon footprint lighter. Plus, upgrading your door is one of those home improvements that instantly boosts curb appeal and pays you back every month.
From material comparisons to leading Energy Star-rated brands, consider this your guide to a door that opens to style, savings, and smarter living.
If you’re serious about savings, fiberglass exterior doors are hands-down the best energy-efficient exterior doors on the market. These doors are designed with a solid polyurethane foam core that acts as a powerful insulator, helping your home stay warm in the winter and cool in the summer.
Unlike metal, fiberglass is a poor conductor of heat, meaning it won’t transfer outdoor temperatures inside your home—no more icy drafts or heat seeping through on scorching days.
But fiberglass doesn’t just excel at energy efficiency; it’s built to last. Unlike wood doors, fiberglass won’t warp, crack, or rot, and unlike steel doors, it won’t dent or rust. The material is exceptionally durable, low-maintenance, and built to handle the harshest conditions.
Many fiberglass doors also feature advanced weatherstripping and insulated glass options, including low-e coatings that further reduce energy loss around glass panels. This all translates to lower heating and cooling costs, reduced environmental impact, and year-round comfort.
Steel exterior doors don’t quite outperform fiberglass in energy efficiency, but they come close—and at a lower cost. For homeowners who want a durable, secure, and energy-efficient door without stretching the budget, a steel exterior door is an excellent all-around choice.
While raw steel isn’t naturally a great insulator, modern steel doors are engineered with insulated cores and thermal breaks that dramatically improve their performance. Similar to fiberglass, these doors often feature polyurethane or polystyrene foam insulation to help block heat transfer, reduce drafts, and keep indoor temperatures stable.
Many models also come with magnetic weatherstripping that forms a tight seal, helping to keep conditioned air inside and outdoor temperatures where they belong.
Not sure which door is right for you? Here’s a quick side-by-side look at the best insulated exterior doors so you can compare their energy efficiency at a glance.
|
Category |
Fiberglass Exterior Doors |
Steel Exterior Doors |
| Energy Efficiency | Superior—Excellent insulation, poor conductor of heat, often highest Energy Star ratings. | Very Good—Insulated steel doors with thermal breaks perform well. Slightly less efficient than fiberglass. |
| Insulated Core | Yes—Solid polyurethane foam core for top-tier insulation. | Yes—Polyurethane or polystyrene insulated cores. |
| Thermal Conductivity | Very low—Maintains consistent temperature. Minimal heat transfer. | Moderate—Steel conducts heat, mitigated by thermal breaks. |
| Weather Resistance | Exceptional—Won’t warp, crack, or rot. | Excellent—Resistant to harsh weather but can dent or rust over time. |
| Longevity | High—Extremely long-lasting. Decades of reliable performance. | Moderate to High—Very durable but may dent and needs protection from rust. |
| Environmental Impact | Very energy-efficient in use; manufacturing is more energy-intensive. | Energy-efficient when insulated; steel production has a higher carbon footprint. |
| Cost | Higher upfront cost but energy savings pay off over time. | More affordable than fiberglass. Great value for performance. |
Beyond their timeless beauty and unmatched craftsmanship, exterior wood doors naturally perform well when it comes to insulation. Wood is an organic insulator with a relatively high R-value, meaning it slows the transfer of heat better than many other materials. This makes solid wood doors an energy-efficient choice compared to hollow-core or metal-only doors.
A well-made, solid wood door can help maintain comfortable indoor temperatures year-round. Wood’s dense composition also allows for a tighter seal against your door frame, minimizing drafts and reducing the risk of air leaks that can drive up utility bills.
That said, while solid wood doors do offer impressive performance, they aren’t considered the best energy-efficient exterior doors available. Wood doesn’t quite match the performance of fiberglass or insulated steel doors, which are engineered with specialized cores and thermal breaks to minimize energy transfer. Wood doors rely primarily on the natural insulating properties of wood itself.
A solid door with no glass will always provide the best overall insulation and energy efficiency. Glass, by nature, doesn’t insulate as well as fiberglass, steel, or wood. However, that doesn’t mean you have to give up your dream of a beautiful, light-filled entryway.
As mentioned before, the key is choosing a door with energy-efficient glass, like low-e glass panels. Low-e glass is coated with a thin, invisible metallic oxide layer that reflects infrared and UV rays. This allows natural light to brighten your home while helping to keep heat outside in the summer and inside during the winter.
For even greater performance, many modern doors feature double- or triple-pane glass with argon gas insulation between layers—further reducing heat transfer and improving overall energy efficiency. Combine that with a high-quality, well-insulated door frame and proper installation, and you can enjoy the look of glass panels without sacrificing energy savings.
If you’re looking for a new door, you’ll quickly discover there’s no shortage of options. But which brands can be trusted for the best energy-efficient exterior doors?
At Zeeland Lumber & Supply, we work with the top names in the industry every day, and these are the brands we consistently recommend when homeowners are looking for style, performance, and the best energy efficiency available.
When it comes to exterior doors, Therma-Tru is a name synonymous with innovation and performance. Their industry-leading fiberglass doors are designed with a polyurethane foam core that offers exceptional insulation, making them some of the best energy-efficient exterior doors on the market. Many of their models are ENERGY STAR® certified, and their decorative and privacy glass options often feature triple-pane, factory-coated Low-E glass for superior thermal performance.
Even better? Choosing an ENERGY STAR-certified Therma-Tru door can help you qualify for certain federal tax credits and energy-efficient mortgages, making it a smart investment for both your home’s value and your monthly energy bills. With thousands of design options that combine beautiful aesthetics with high-performance construction, Therma-Tru delivers a door that looks stunning and saves you money.
Glenview Doors combines the elegance of traditional wood design with cutting-edge performance, thanks to its proprietary EuroTech™ construction. This unique “sandwich” design features a thermal insulating core and engineered stiles and rails, delivering superior thermal performance, improved weather resistance, and long-term durability compared to traditional solid wood doors.
At 2 ¾” thick, Glenview door slabs are nearly twice as thick as standard wood doors, enhancing insulation and structural stability while resisting warping, cracking, and splitting over time. The result? A door that looks like handcrafted wood but performs like a modern engineered system—keeping your home comfortable and energy bills lower.
Glenview also offers modern steel and aluminum door designs, providing even more options for homeowners who want sleek, contemporary style paired with exceptional energy efficiency. Whether you choose one of their modern aluminum-glass designs or a classic wood-inspired entry door, Glenview delivers a premium, energy-smart product with a luxury aesthetic.
For more than 115 years, Andersen has been a pioneer in sustainable building solutions, and their exterior doors are no exception. Andersen’s collections, including their highly regarded 100 Series patio and entry doors, are built using their proprietary Fibrex® composite material—a durable, eco-friendly alternative to vinyl that offers outstanding insulation.
Andersen doors are recognized for their exceptional energy efficiency, featuring tight weatherstripping systems, high-performance Low-E glass, and precision engineering that minimizes air infiltration.
Their long-standing commitment to sustainability has earned them multiple ENERGY STAR® Partner of the Year Sustained Excellence Awards, ensuring that when you choose Andersen, you’re not only investing in a high-performance product but also supporting an environmentally responsible company.
Is your current door letting energy (and money) slip right through the cracks? Upgrade to an energy-efficient exterior door and start enjoying a more comfortable home and lower utility bills.
At Zeeland Lumber & Supply, we carry a wide selection of the best energy-efficient exterior doors from top brands—from top-tier fiberglass to secure steel and stunning wood designs.
Visit one of our showrooms or connect with our team today. It’s time to make your exterior doors work for you, not against you.
This website uses cookies.