What to Do with a Fireplace You Can't Use: Modernising a Decommissioned Chimney Breast

There are a lot of them in UK homes — chimney breasts that were blocked up decades ago, gas fires that were disconnected when central heating arrived, old back boilers that have long since been removed.

The opening is still there, or at least the recess is. The chimney breast still dominates one wall of the room. And the question, eventually, is what to do with it.

Leave it as a dead feature, or turn it into something that actually works.

For homeowners renovating or redecorating, a decommissioned fireplace is one of the most interesting problems a room can have — and one of the most satisfying to solve.

Understanding What You're Working With

Before deciding on an approach, it helps to understand what type of decommissioned fireplace you have. The situation varies more than most people expect.

Some chimney breasts have been fully blocked and plastered over, leaving only the external projection of the breast visible in the room. Others have a fireback intact with a blocked flue above it. Some have been fitted with a decorative surround over an empty recess, or have an old gas fire still in place that was simply switched off and forgotten.

In some cases, particularly in Victorian and Edwardian terraces, the chimney above roof level has been removed entirely — which means even if the flue were reopened, it couldn't be used for a working fire.

The condition of the flue matters if you're considering a solid fuel or gas installation, but for the majority of modern fireplace options — electric fires, bioethanol burners, and built-in inserts — it's largely irrelevant.

These installations don't require an active flue, which is exactly what makes them well suited to decommissioned chimney breasts.

The Case for Keeping the Chimney Breast

Removing a chimney breast is a structural job that requires building regulations approval, temporary support while the work is carried out, and often a significant amount of replastering and redecorating afterwards.

It's not always the straightforward solution it appears to be on a floor plan.

More practically, the chimney breast gives the room something most open-plan modern interiors actually lack: a natural focal wall.

The projection creates depth, a sense of hierarchy between the walls, and a logical place for the room to organise itself around.

Working with it, rather than against it, tends to produce better results than removing it and starting from scratch.

The recess itself is also genuinely useful. At a typical depth of 200–300mm, it's enough to accommodate a built-in electric fire flush with the surrounding wall — which creates a much cleaner, more architectural result than a surface-mounted unit sitting proud of the plasterwork.

Fitting a Modern Fire into an Existing Recess

For most homeowners, fitting a new fire into a decommissioned opening is the most satisfying route — it gives the room back its focal point without requiring any structural work.

The choice of fire type comes down to the specific space and what you actually want from it.

Electric Fires

Built-in electric fires are the most straightforward option for a decommissioned chimney breast.

They require only a standard electrical connection, no ventilation, and no modification to the flue.

Many are designed specifically for inset installation, sitting flush within a recess and framed by the surrounding plaster or a purpose-built surround.

Modern electric fires have moved a long way from the bar fires of the 1980s.

Contemporary models use LED technology to produce flame effects with genuine depth and movement — some with log beds, some with purely abstract ember effects, and others with a clean, linear flame that suits a more minimal interior.

Many also include optional heat output, which means the fire can function as a supplementary heat source as well as a decorative feature.

If you're exploring built-in electric fires for a decommissioned opening, browse our collection here:
👉 https://luxergyheating.co.uk/collections/built-in-electric-fires

Bioethanol Burners

A bioethanol burner installed within an existing fireplace recess produces a real flame — clean-burning, with no smoke and no requirement for a working flue.

Bioethanol burns without producing soot or particulates, which makes it suitable for a blocked chimney breast provided there is adequate ventilation in the room, as with any open flame.

The result, visually, is very close to a traditional wood fire — but without the maintenance, the fuel storage, or the chimney sweep.

A built-in bioethanol burner recessed into an original fireplace opening, framed by an existing surround or a simple plastered reveal, can look as though the room was always designed around it.

Treating the Chimney Breast as a Design Feature

Not every decommissioned chimney breast calls for a new fire.

In some rooms — particularly those with a strong existing heating system — the priority is visual rather than functional.

Here, the chimney breast can be treated as an architectural feature in its own right.

One approach is to use the recess for built-in storage or shelving, flanked by alcove units on either side.

This is one of the most common treatments in UK living rooms and works well because it gives the chimney breast a clear purpose.

The fireplace opening becomes a cupboard, a display space, or a spot for a television — integrated rather than awkward.

A more considered approach is to use the chimney breast as a material feature — cladding it in stone, polished plaster, or timber panelling to create a wall that has genuine presence.

Even without a fire, a chimney breast treated this way becomes the room's focal point.

It works particularly well in rooms that are otherwise neutral in finish, where the material contrast provides the visual interest the space needs.

What to Avoid

The least successful treatment for a decommissioned chimney breast is usually the most common one: filling the opening with a flat board, painting everything the same colour as the walls, and hoping it disappears.

It rarely does.

The projection is still there, the room still organises itself around it, but there's nothing for the eye to land on.

The result is a room that feels slightly unresolved.

Similarly, adding a purely decorative surround around a flat-boarded opening — with no fire, no light source, and no depth behind it — can feel unconvincing.

A surround works when it frames something.

Without a fire or at least a considered interior treatment, it tends to draw attention to what's missing rather than adding to the room.

Getting the Proportions Right

Whatever approach you take, proportion matters.

The opening size of a Victorian or Edwardian fireplace — typically around 400–500mm high and 450–600mm wide — is smaller than most modern electric fires are designed for.

A built-in installation often requires the original opening to be widened or the recess to be extended to accommodate a contemporary fire, which is straightforward building work but worth factoring into the project.

Conversely, a fire that is too small for the chimney breast will look as though it was an afterthought.

The fire should relate meaningfully to the width of the breast above it.

As a rough guide, a fire that spans at least half the visible width of the chimney breast tends to look intentional rather than incidental.

A Problem Worth Solving Well

A decommissioned chimney breast is one of those features that rewards a considered response.

Left unaddressed, it tends to make a room feel slightly incomplete.

Approached thoughtfully — with the right fire, the right finish, or both — it becomes one of the most characterful elements the room has.

For UK homes in particular, the chimney breast is part of the building's history.

Bringing it back to life with a modern fire that suits the space is often the simplest way to make a room feel both current and grounded at the same time.

Explore the Collection

If you're working through options for a decommissioned fireplace, explore our range of electric fireplaces — from compact inset models to wider linear fires designed to suit a variety of chimney breast widths and interior styles.

👉 Browse the collection at:
https://luxergyheating.co.uk/collections/electric-fireplaces

Each design is selected to combine contemporary styling, realistic flame effects, and straightforward installation — making it easier to bring an unused fireplace back to life.