Renovate an old fireplace guide
May 08, 2026
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That old stone fireplace sitting dormant in your living room?
It doesn't have to stay that way. With a custom-built ethanol firebox insert, you can transform a cold, unused wood-burning hearth into a stunning, fully functional bioethanol fireplace - without demolition, without a flue, and without any structural changes to your home.
This is exactly what we did for a client with a classic lava-stone fireplace. The opening was measured precisely, a bespoke black steel firebox was fabricated to fit perfectly within the existing cavity, and the Afirebox smart ethanol burner was recessed directly inside. The result: a completely transformed feature that keeps the character of the original stonework while adding a clean, contemporary flame.
How the Retrofit Process Works
Measure the Inner Clearance
The first step is taking precise internal measurements of your existing fireplace opening - width, height, and depth. These three dimensions define the custom firebox that will be fabricated. Our team can guide you through what to measure, or we can assess remotely from photos.
Custom Firebox Fabrication
Using your measurements, we fabricate a powder-coated steel firebox built to slot perfectly into the cavity. The box lines the interior, provides a clean black surround, and houses the ethanol burner unit. No gaps, no adapters - a precision fit every time.
Install the Ethanol Burner
The Afirebox smart burner is recessed into the firebox. For automatic models, a power cable is discreetly routed through the base or side of the firebox. The burner is then secured, tested, and ready to operate - no gas line, no chimney work required.
Recess & Finish
The firebox slides into the existing opening and sits flush with the original stone or brick surround. The original character of the fireplace is completely preserved - only the cold, dark void is replaced with a warm, living flame.
iNSTALLATION GUIDE
Side profile- firebox sitting and pushing into the stone surround
Side profile - firebox depth alignment with the existing stone surround
3D concept render - firebox unit shown beside and recessed into the cavity
Installation Notes
Key requirements and recommendations before proceeding with a retrofit installation.
Measure Three Times
Provide width, height, and depth of the inner cavity at the narrowest point. Stone and brick openings are rarely perfectly square - measure at both sides and take the smaller dimension to ensure the firebox fits without force.
Power Supply for Smart Burners
Automatic ethanol burners require a 220V / 110V power connection. Plan a discreet cable route through the hearth base or side wall before the firebox is installed. A licensed electrician should complete this step.
Seal the Old Flue
The original chimney flue must be sealed before use. An open flue creates a draught that can destabilise the bioethanol flame and draw combustion gases upward unexpectedly. Use a fireplace balloon or solid cap - your installer can advise.
Stone Surround Compatibility
Natural stone, brick, and lava rock surrounds are all fully compatible - they are inherently non-combustible. No heat shielding is required between the steel firebox and existing stone. Minimum 50 mm clearance on all sides is recommended for airflow.
Ventilation Requirements
Even with the flue sealed, ensure the room has adequate air exchange. The room volume should be at least 37–40 m³ per EN 16647 guidelines. A trickle vent or slightly open window is sufficient for most living rooms.
OEM Custom Sizing Available
Every fireplace opening is different. Afirebox fabricates custom firebox dimensions to order - any width, height, or depth. Lead time is typically 3–5 weeks depending on specification. Contact us with your measurements for a quote.