03/01/2024 Posted By Siarhei Kanushok


Without going into too much detail, all doors fall into two broad, equally essential categories: exterior and interior. They differ in the place of use, which entails a massive list of differences, including the material of manufacture, type of finish, and other technical characteristics. Also, doors have different prices.

Since both types of doors are needed in any residential and commercial building (stores, offices, hotels, hospitals, etc.), selecting them is always multi-step. It requires careful preparation; here, we will compare interior and exterior doors.


Door slab material

Most often, the primary material for manufacturing doors is wood. However, wooden entrance doors will not last as long as steel doors because they are more susceptible to temperature fluctuations and humidity. In addition, steel doors "block" noise and keep the heat inside the apartment, providing the owners a quiet and cozy atmosphere.

Interior doors are also, in most cases, made of wood, but for some needs, the material can be plastic (for example, for balcony doors).

Door frame material

In our product range, the frame of the front doors is made of galvanized steel for durability and reliability, which is not afraid of mechanical damage and corrosion. Quality entrance doors have a thermal break, which gives them high thermal insulation properties and keeps your home warm even at very low temperatures.

When it comes to interior doors, a solid wood frame is the best solution. Thanks to this frame, the door will be long-lasting.

Door filler material

Here's a look at some of the standard door fillers used.

Interior doors

  1. Solid wood: it is the traditional material for exterior and interior doors.

  2. Solid core: one of the highest quality and most popular materials we use is engineered solid core, which is an innovative, eco-friendly wood fiber material with 12.5 lb/ft³ density. It is responsible for soundproofing and keeping heat inside the room.

  3. MDF (Medium Density Fiberboard) panels: this material is often used as a base for solid wood doors, providing a smooth surface that can be painted or veneered. They offer a good balance between weight, insulation, and cost.

  4. Polystyrene: its main advantages are durability, sound, and heat insulation.

  5. Fiberglass: it is highly energy efficient, durable, and resistant to warping, rotting, and rusting, making it suitable for both exterior and interior doors.

  6. Hollow core: these internal doors have a lightweight, hollow center, typically made from a honeycomb core, so manufacturers offer their production at low prices. 

Exterior doors

  1. Solid wood.

  2. Steel: steel doors are characterized by strength, security, and weather resistance.

  3. Fiberglass.

  4. Foam insulation: polyurethane or polystyrene.

  5. Honeycomb core: a lightweight and cost-effective option.

  6. Mineral wool: This material is known for its fire-resistant properties, making it an excellent choice for exterior doors requiring extra security. It also provides good thermal and acoustic insulation.

  7. Composite materials: Some modern doors use fillers made from wood fibers, plastic, and binders.

Finishing material

Interior doors are usually covered with enamel, polypropylene, veneer, or primer. The last of them you can design to your taste: wallpapered, painted in any color (for example, in the shade of the walls), or finished with decorative plaster.

Because front doors must withstand many external factors, we finish with extra durable painting with reliable protection from UV rays.

Material of decorative elements

Door slabs can be decorated with filets, 3D milling, aluminum strips, or glass inserts. Only glass used for interior doors is not suitable for front doors. So, Belldinni exterior doors are equipped with glass, a triple-sealed unit with two chambers: it is tempered on both sides and has silkscreen printing using ceramic inks.


In general, entry door slabs are twice as thick as interior door slabs because they have to protect the house or apartment from harsh weather conditions, draughts, and noise. They are also a barrier against criminals, i.e., they provide security and burglary resistance.

Even though interior doors are much thinner than the entrance, some models can guarantee good heat and sound insulation.


Interior doors zone the space, become its accent element, and protect the room from unnecessary sounds, but the function of entrance doors is much more extensive. Thus, the price of entry doors is higher because they are made of more efficient and expensive materials.

What affects the price of a door?

  • Material.

  • Slab thickness.

  • Slab size.

  • Door filler.

  • Decorative elements.

  • Finish.

  • Configuration (opening system).

  • Hardware.


The front door is "the visiting card" of your house or apartment, so now many models have different modern designs. However, their primary function is to provide security.

Consequently, the range of interior doors is still much more comprehensive. They can be decorated with mirrors, glass, aluminum strips, grooves, etc.


The amount of space required for the door depends on the width of the doorway and the configuration. Entrance doors often open outwards from the house or apartment, so the space available inside is not reduced.

Double swing interior doors require a lot of space because their opening and closing radius is large. However, many people choose sliding doors. They are easy and convenient to use and are compact.


Of course, interior and exterior doors differ in their purpose, affecting the noise insulation level.

Home is a safe island where you want comfort and silence, so sometimes, when buying a door, design, type of finish, and other technical characteristics are in the background, and the main criterion is the ability to protect from extraneous sounds. Interior doors have a lower level of noise insulation, while many Belldinni entrance door models absorb noise up to 37 dB. 


Exterior doors and interior doors are fundamentally different products that do not replace one over the other. They differ in almost all parameters, as they perform essential functions.

Remember that quality doors are a long-term investment in your home, so choose them wisely. If you still have questions, our experts will help you find the best front or internal door model.