How To Compare Fireplace vs. Firebox vs. Insert

Outfitting or renovating your home with a new hearth or fireplace is a big project, and the process often becomes more complicated when you actually have to decide what type of fireplace you want.

Chances are you’ve heard the terms “fireplace,” “firebox,” and “insert” before. These three terms are often used interchangeably, but they actually mean different things. Your unique situation, layout, and budget will determine which of the three you should actually shop for, whether it’s a complete fireplace unit, a replacement firebox, or an insert that goes into an existing opening. The guide below will help you make the best choice for your home and explain what each term means. Blazzing Fire’s team walks buyers through this exact decision daily, as a one-stop hearth retailer carrying gas, electric, and wood burning fireplaces, fireboxes, and inserts alike.

What Is a Fireplace?

A fireplace is arguably the most recognizable of the three terms we are thinking about. The term “fireplace” is often used to describe fireboxes and inserts as well, but in strictly technical terms, a true fireplace refers to a complete heating and flame unit. Fireplaces are architectural pieces that include an outer mantel, a hearth, a firebox, and a chimney or flue.

Fireplaces can be gas, electric, or wood burning, and they include a comprehensive surrounding structure. Fireplaces can be open masonry or factory-built, and while they are the most impressive to look at, they often have lower heating efficiency, as most of their warmth escapes up the chimney.

What Is a Firebox?

In contrast to a complete fireplace, a firebox is the specific interior chamber where combustion or a flame effect actually happens. You can think of it this way: every fireplace contains a firebox, but fireboxes themselves are not a full fireplace.

Fireboxes are typically made of firebrick, refractory mortar, or heavy metal, and are designed to withstand extreme temperatures. They are generally what gets replaced or rebuilt in a full remodel. Notably, fireboxes cannot function on their own without some sort of venting or framing infrastructure. This doesn’t have to be a full fireplace, but a firebox needs at least some venting.

What Is an Insert?

Finally, an insert is a self-contained unit that is built to drop into an existing fireplace opening, often slid directly into an existing, old firebox. Inserts are often made of high-efficiency steel or cast-iron, and are most often used to convert an old wood burning setup to gas or electric.

Inserts can be powered by gas, wood, pellets, or electricity, and many electric inserts can easily replace old wood-burning fireboxes. This makes them a great choice for a quick, modern remodel or replacement.

Side-by-Side: How Fireplaces, Fireboxes, and Inserts Stack Up

How To Choose Between a Fireplace, Firebox, or Insert

Depending on the current layout and setup of your home, as well as your remodel or construction plans, follow this easy checklist to determine whether a fireplace, firebox, or insert is best for you:

New Construction: totally ground-up architecture

• Best Option: Complete Fireplace

• Why: Fully-integrated into new construction with new venting, framing, and insulation, including media wall builds designed around the fireplace from the start

Bare Wall: no existing opening or masonry structure

• Best Option: Complete Fireplace

• Why: Designed to be built into existing studs and match bare wall architecture

Structural Opening Only: newly framed wall cutout or an empty brick structure

• Best Option: Firebox

• Why: The sole necessity is the inner combustion chamber shell; custom mantels and finishes can be added on

Existing Masonry or Prefab Fireplace: open, drafty, low-efficiency wood fireplace with a working chimney

• Best Option: Insert

• Why: Slides directly into the existing opening to seal out drafts and improve heating efficiency

Why Making the Right Choice Matters

Choosing the right heating unit for your home or remodel is very important. You not only have to handle budget concerns, but also understand the architecture, layout, and design of your space to maximize the utility and functionality of your unit.

No matter your needs, Blazzing Fire is the best one-stop hearth retailer you can turn to for any fireplace, firebox, or insert project. Founded in 2016 by fireplace and chimney professionals, Blazzing Fire brings trade-level hearth expertise to online buyers and offers a wide range of products, including gas logs, gas, electric and wood burning fireplaces, mantels, venting and outdoor fire units.

Blazzing Fire is an authorized dealer for every brand it sells, with full manufacturer warranties and technical support on every order.

Visit our online store to learn more about Blazzing Fire’s high-quality fireplaces and inserts.

Frequently Asked Questions

What is the difference between a firebox and a fireplace insert?

The difference between a firebox and a fireplace insert exists in their size, function, and purpose. A firebox is the specific interior chamber where combustion or a flame effect actually happens in a fireplace, which can be purchased on its own, but requires ventilation and framing. An insert is a self-contained unit that is built to drop into an existing fireplace opening to replace or update an old firebox, such as by adding electricity in place of wood-burning.

Can I put an insert into any existing fireplace?

You cannot always put an insert into any existing fireplace. Insert compatibility depends on a variety of factors, including existing fireplace measurements, utilities, and building codes. Traditional brick or stone masonry fireplaces can usually accommodate most inserts, while prefabricated (zero-clearance) fireplaces may require specific, manufacturer-approved inserts to avoid a fire hazard. 

Do I need a new firebox or just an insert for my remodel?

Whether you need a new firebox or just an insert for your remodel depends on the setup of your current fireplace. In general, inserts are preferable if you have a structurally-sound masonry or factory-built firebox you want to replace or refit. You will typically be better off with a new firebox or a complete fireplace if you are constructing from scratch, tearing down old framing, or doing a structural overhaul in your remodel.