What Is the Difference between Interior and Exterior Doors? An In-Depth Look

Published: October 28, 2021

By the Estate Millwork Design Team | Craftsmen since 1997

What Is the Difference between Interior and Exterior Doors?

A door is an important mechanism designed for specific uses in certain situations. That is why choosing the proper door types for your home is an important decision. What makes an interior door different from an exterior door? We'll give you a hint; it's more than where they are located in your home. There are many differences between the two doors that even the most seasoned contractor can sometimes overlook. One door provides a barrier between rooms within your home and the other protects your home from the exterior elements.

Door differences

Interior and exterior doors can be similar in appearance to exterior doors but can also differ in some aspects.

Exterior doors

Functions as the main entrance to your home
Insulates your home from exterior elements and sound
Typically thicker and heavier than interior doors
Have more security features than their interior counterparts

Interior doors

Separates rooms inside your home
Usually thinner and lighter than exterior doors
Provides a sound barrier and has thermal properties to keep heat or cool air within a room

Material differences

While both interior and exterior doors can use the same wood types, some types may be better for different applications.

Interior doors

Can be a combo of wood and glass or just wood
Pretty much all hardwood species are suitable for interior applications
Can be stained or painted

Exterior doors

Thermal insulator between your home and the outside
Can be a combination of glass and wood or all wood.
Some hardwoods are better than others for exterior use where the doors exposed to the exterior elements

Thickness Differences

When it comes to interior and exterior doors; exterior doors are typically thicker than interior doors. Exterior doors are thicker to protect your home from exterior elements such as unwanted visitors and weather, the thicker exterior door provides better thermal and sound insulation over their thinner interior counterparts.

Frequently Asked Questions

What wood species work best for interior doors?

Poplar is the most popular choice for painted interior doors due to its smooth grain and affordability. For stained doors, Red Oak, Maple, Cherry, and Walnut each offer distinctive grain patterns and color tones. The best species depends on whether you plan to paint or stain.

How are custom wood doors different from big-box store doors?

Custom wood doors are built to your exact dimensions using solid hardwood and traditional joinery methods like mortise and tenon. Big-box store doors are typically hollow-core or use engineered materials. Custom doors offer superior sound insulation, durability, and a solid feel that mass-produced doors cannot match.

Can I order a custom door in a non-standard size?

Yes. Estate Millwork builds every door to your specified width and height. Whether you need a narrow pantry door, an oversized entry door, or a door to fit a historic opening with non-standard dimensions, we can accommodate your requirements.

What door styles does Estate Millwork offer?

We offer louvered, raised panel, flat panel, French, barn, arched, and mission style doors. Each style is available in multiple wood species and can be ordered painted or unfinished. Our online designer lets you configure every detail and see an instant price quote.

Design Considerations for Custom Wood Doors

Measure the rough opening, not the existing door, when ordering a replacement. Include the width, height, and wall thickness so the door and jamb fit correctly.
For high-traffic areas like kitchens and hallways, choose a harder wood species like White Oak or Maple that resists dents and wear better than softer species.
Louvered doors are an excellent choice for closets, laundry rooms, and utility spaces because the slats promote air circulation, reducing moisture buildup and musty odors.
When matching new doors to existing trim, bring a sample of your current wood or finish to compare. Estate Millwork offers the same species and can match stain colors for a cohesive look.