Energy Efficient Doors Buyers Guide

While most of us probably equate cold and drafty homes with old windows or inadequate insulation, we may not realize that doors may be to blame. The doors in our homes play an essential part in maintaining (or neglecting) the energy efficiency of our homes. According to the California Energy Commission, doors are responsible for up to 11 percent of all air leaks in a home, despite representing a relatively small amount of the total wall space. Even if a door is exceptionally well-sealed, heat transfer is bound to be a problem due to the relatively low insulation in doors and door frames.

Investing in the best energy-efficient doors is a cost-effective way to increase the energy efficiency of your home. It also improves the aesthetics of your home facade. And if you aspire to meet the standards of Passive House, energy-efficient doors are a must.

These weatherproofing strategies can certainly help reduce your doors' energy loss; however, a new door is worth considering.

What to Look for in Energy Efficient Doors

Energy-efficient doors come in various styles and designs, though all will share specific characteristics and performance qualities. When searching, consider some of the following features:

Solid wood doors also have a higher R-Value than uninsulated metal and fiberglass doors, offering better insulation capabilities. However, these types of doors and door frames are prone to warping or drying out over time. It can lead to cracks and gaps that let drafts into your home and thus compromise your house's thermal performance.

Fiberglass and steel doors, on the other hand, tend to have a higher embodied energy footprint than wood but can be manufactured to limit the possibility of drafts occurring. Fiberglass is durable and lightweight, thus minimizing the door's likelihood of pulling away from the frame and causing drafts to occur. Similarly, because of steel's strength, doors manufactured from this material can be made hollow to be filled with some insulation material subsequently. In terms of insulation values, a solid wood door that is 1 3/4" thick is expected to have an R-value of 2.17. A 1.5" to 2" metal door insulated with polystyrene insulation is calculated to have an R-value of anywhere between 6 and 7.

If you want a door that allows for natural lighting, opt for double-pane (or triple-pane) inserts that are argon-filled. Argon-filled inserts can at least double the insulation properties. Prioritizing Low-E glass can also improve the performance of the door. This type of glass improves the insulating properties of windows in the home through a coating that can reflect infrared and ultraviolet (UV) radiation. This will keep the hot sunlight from entering your home during the summer while keeping the heated air inside your home during the winter.

Exterior Door Insulation and Framing Options

Solid wood doors have no extra insulation on the inside, as they are made from solid pieces of wood. While thicker doors offer a unique aesthetic coupled with decent insulation capabilities, this door option is often beyond most homeowners' budgets. Hollow-core doors made from fiberglass, steel, or composite wood veneer, are usually much less expensive. However, due to their lightweight and thin nature, these types of doors would offer virtually no insulation value if they were left hollow. One of the best materials to fill the sizeable hollow space within the door is insulating foam, which increases the door's R-value without adding significant weight.

Solid core doors are made with wood veneers glued over a solid core of composite or engineered wood. These doors are usually less expensive than solid wood options, though they offer similar insulation properties. Because they are made from manufactured wood, they are less prone to shrinkage and warping from exposure to the elements. Be sure to look for solid core doors that don't rely on formaldehyde as a bonding adhesive.

Some of the most modern doors on the market come with improved door frames incorporating magnetic strips around the door frame. Pieces of metal in the door adhere to that strip, creating a tighter seal and further reducing the possibility of drafts and leaks.

Our Picks for the Most Energy Efficient Door Manufacturers on the Market

While there are hundreds of companies producing top quality doors that prioritize energy efficiency considerations, some of the top manufacturers recognized by the ENERGY STAR certified include:

Therma Tru Doors

Therma Tru Doors manufactures a wide range of energy-efficient door styles that contain a polyurethane foam core, energy-efficient glass, and weather stripping components. The weatherstripping components help to create a tighter seal and reduce air leakage around the edges.

ProVia Fiberglass Doors

ProVia Fiberglass Doors specializes in fiberglass doors that are 2.5 "thick to allow for extra insulation. Their doors also include a dual perimeter seal, which seals on the door and frame to make the door more energy efficient.

Global Windows and Doors

Global Windows and Doors offers a wide range of doors made from wood, fiberglass, steel, and other materials. Their line of steel doors are made from finger-jointed knot-free pine stiles and rails for strength and durability with 24 gauge steel and HCFC free polyurethane foam insulation.

Groke Aluminum Doors

Groke Aluminum Doors is a German manufacturer of aluminum doors, makes custom entry doors that qualify as Passive House doors. Their doors are super insulated and tightly sealed, with U-Factor ranging 0.13 to 0.257. Their U.S.-based office is located in Charlotte, North Carolina.

Hammer & Hand Doors

Hammer & Hand Doors are made in Portland, Oregon. Hammer & Hand custom manufactures wood doors that are built to the Passive House standard.

It doesn't matter your choice of manufacturers. It's important to remember that the doors in your home can significantly impact your home's comfort and energy efficiency - so don't forget about them!

Article by:

Tobias Roberts

Tobias runs an agroecology farm and a natural building collective in the mountains of El Salvador. He specializes in earthen construction methods and uses permaculture design methods to integrate structures into the sustainability of the landscape.