Standard Fireplace Sizes & Dimensions Guide 2026

Standard Fireplace Types Compared

Open Fireplace Key Dimensions

Inbuilt Gas Fireplace Dimensions

Electric Fireplace Sizes Compared

Wall-Mounted Electric Fireplace

Inbuilt / Recessed Electric Firebox

Recessed electric fireboxes like the Dimplex Evo range sit flush with the wall for a clean, built-in look. Available in widths from 75 cm to 90 cm and portrait orientations for tall media wall designs.

Freestanding Wood Heater Sizes & Dimensions

Freestanding wood heaters offer the warmth and ambience of a real wood fire without the construction involved in a built-in masonry fireplace. Slow-combustion models are the most efficient, burning wood longer and cleaner with adjustable air vents and secondary combustion systems. Suspended designs, like the Tarvos from Schots, are architecturally stunning and can rotate 360 degrees to direct heat anywhere in the room. Because they sit in the middle of or against a wall, clearance requirements are very important for safety and compliance with AS/NZS 2918.

Standard Freestanding Wood Heater

Suspended Wood Heater

Additional Fireplace Sizing Considerations

1. Hearth material and size: Under the NCC, open fireplaces must have a non-combustible hearth (concrete, stone, tile, or slate) that extends at least 30 cm in front of the opening and at least 15 cm beyond each side. For freestanding heaters, this increases to 40 cm from the appliance. Always confirm with your installer before tiling or laying flooring around the fireplace.
2. Flue height and clearance (wood and gas): For wood-burning appliances, AS/NZS 2918 requires the flue to be at least 4.6 m in height from the floor to the flue cap. The cap must also extend at least 600 mm above the highest point of the roof within a 3 m radius. Additionally, the flue cap must have at least 3 m of clearance from any nearby roof structure, trees, or second-storey walls, and at least 6 m horizontally from any neighbouring structures or buildings. Always confirm exact flue termination requirements with your licensed installer and local council.
3. Room size and heat output matching: A fireplace that's too small won't heat efficiently; one that's too large will overheat the space and waste fuel. Use the table above as a starting guide and always check the manufacturer's specific guidelines.
4. Mantel proportions and clearance: The mantel shelf should sit at least 30 cm above the top of the fireplace opening. A well-proportioned mantel extends around 15-20 cm beyond each side of the firebox opening, so a 90 cm firebox would typically suit a mantel around 120-130 cm wide. Always check the heat clearance requirements for the specific fireplace model, as some require greater distances from combustible timber mantels.
5. Wall clearance from combustibles for gas and electric: Gas fireplaces require clearance from combustible wall materials - always refer to the manufacturer's specifications and local council requirements. Electric fireplaces have much smaller clearance requirements, though items should still be kept at least 1 m from the front of the unit during operation.

Common Fireplace Materials

The material of your fireplace surround, mantel, and firebox affects not just aesthetics but also weight, installation complexity, heat performance, and long-term maintenance. In Australia, timber remains the most popular choice for fireplace mantels due to its versatility and warmth, but stone, cast iron, and steel all have a strong presence in the market.

Timber

Timber mantels are the most common choice in Australian homes. Craft wood (MDF-based) options are affordable and pre-primed for painting, while solid timber choices like oak or pine add genuine authenticity.

Marble and Stone

Marble and natural stone mantels are a hallmark of period homes and high-end renovations. Schots carries one of the largest marble mantel ranges in Australia, including Italian Carrara white, Belgium black limestone, and Bianca white statuary marble. Stone mantels tend to be heavy, anywhere from 80 kg to well over 200 kg, so wall fixings and floor supports need to be assessed before installation.

Cast Iron

Cast iron is the traditional material for fireplace inserts and fascias, particularly in period-style homes. It retains heat long after the fire has died down and provides excellent radiant warmth. Most inserts weigh between 40 kg and 100 kg.

Steel

Steel is the dominant material in modern gas fireplaces and suspended wood heaters. It heats up quickly, allows for sleek contemporary designs, and is far lighter than cast iron or stone. Steel fireplaces tend to have a smaller footprint for the same heat output compared to masonry counterparts.

For heritage renovations, cast iron or marble is hard to beat. For new contemporary builds, steel and electric options offer the cleanest aesthetic. Timber mantels suit almost any style and budget.

Top 7 Tips for How to Choose the Right Fireplace Size and Style

• Measure the room before you measure the fireplace. Work out the total floor area (length x width in metres). This will help you match the heat output to the room size. A fireplace rated for 80 m2 will be inefficient and potentially dangerous in a 20 m2 bedroom.
• Check your wall space, including the wall cavity. For inbuilt gas and electric units, confirm how deep your wall cavity is. Gas fireplaces typically require 35-50 cm of depth; electric fireboxes need around 15-25 cm. Brick or double-brick walls may need additional framing.
• Know your fuel type before you choose your size. Wood-burning fireplaces need a larger firebox and a compliant flue, a structural consideration that affects the overall footprint significantly. Gas fireplaces offer more flexibility. Electric fireplaces require no flue at all.
• Account for hearth dimensions in your floor plan. The hearth must extend a minimum of 30 cm in front of open fireplaces and 40 cm from freestanding heaters. Plan this into your floor space before you commit - it eats into the room more than most people expect.
• Match the mantel width to the firebox, not just the wall. A good rule: choose a mantel that extends 15-20 cm beyond each side of the firebox opening. For a 90 cm opening, look for a mantel 120-130 cm wide.
• Check Australian compliance requirements for your specific unit. Wood-burning appliances are governed by AS/NZS 4012 and 4013 for emissions and efficiency, and installation must comply with AS/NZS 2918 and the NCC (current edition: NCC 2022). Gas units must carry AGA certification.
• Think about the room's visual proportions, not just the heat output. In rooms with high ceilings (2.7 m+), a taller mantel or wider firebox tends to look more at home. In compact spaces, a slimline gas or electric unit with a simple surround keeps the room from feeling overwhelmed.

Frequently Asked Questions About Fireplace Sizes