A media wall chimney breast build has three honest routes: frame over the breast, hollow it out, or remove the masonry entirely. Which one fits your room comes down to what sits above the breast, how far it projects, whether the flue is still live, and how much floor you genuinely get back.
Work the phases below in order, ticking each checklist before you spend money.
Phase 1 — Survey what you're building around
AVForums is full of people who designed a media wall, then walked upstairs and found the breast continued through the bedroom into a stack on the roof. Three questions decide the rest:
- Is the fireplace live? A working wood firebox, a vented gas insert and a long-dead Victorian opening are three different projects — and a live gas appliance cannot simply be boxed in.
- What's above it? If the breast projects in the room above and a stack sits on the roof, removing the ground-floor section means that masonry must be carried by something engineered.
- Is it shared? On a townhouse the stack may sit in a party wall with a neighbor's flues alongside yours — a legal question, not just a structural one.
Older homes add lime mortar, which matters enormously for support brackets, and possible asbestos in flue parging or hearth backing — testing is cheap next to abatement labor at $75–$350 per hour.
Important: Never seal or enclose a gas appliance or its flue as part of a media wall. If there's any live gas line at the fireplace, have a licensed gas fitter cap and certify it before framing starts.
Phase 1 checklist
- Fireplace status confirmed: live wood, live gas, or decommissioned
- Rooms above and roofline checked for continuing breast and stack
- Party-wall status and asbestos testing addressed
Phase 2 — Measure the breast, the alcoves and the depth you'd gain
The box-it-in versus rip-it-out argument is really an argument about inches. Measure before you take a side.
| Measurement to take | Why it decides the build |
|---|---|
| Breast projection | Depth you'd recover by removing it, or must match by framing across |
| Alcove depth, both sides | Usable cabinet depth you get for free |
| Alcove width, both sides | Rarely equal in old houses; decides whether the wall can be symmetrical |
| Firebox opening size | The largest electric fire that will drop in |
| Firebox internal depth | Usually shallower than assumed — measure, don't guess |
| Outlet and cable entry points | How much electrical work you trigger |
Firebox depth matters more than it sounds. One AVForums member planning this exact conversion found their recess only about 6 inches deep — not enough to lay a cable box in horizontally, and that box ran hot. A Screwfix thread shows the flip side: a lintel above the TV line, masonry cut out beneath, then 18mm battens and board on the face — barely an inch and a half added to the room for a real recess. Our guide to how deep a media wall should be has the numbers.
Pro tip: Subtract alcove depth from breast projection. If the difference is under about 4 inches, framing flush across the whole wall costs almost nothing in floor space — and removal buys almost nothing either.
Phase 2 checklist
- Every measurement sketched, not held in your head
- Alcove widths compared for symmetry
- Firebox depth checked against the gear you want to hide
Phase 3 — Price the three routes honestly
Treat these as planning ranges, not quotes.
| Route | Typical US cost | Timeline | What it buys you |
|---|---|---|---|
| Frame over the breast | Standard build, no demolition | 2–5 days | Flush wall, hidden cables, TV and fire recess |
| Hollow out the breast | Framing plus lintel and making good | 3–7 days | Deep recess without pushing into the room |
| Remove breast, ground floor | $1,500–$2,500 plus ~$2,500 support and patching | 3–5 days | Breast projection back in the room |
| Full removal with stack | $4,000–$10,000, average near $4,500 | 1–2 weeks | Flat wall, no stack to maintain |
Then add what national cost guides list separately: engineer consultation averaging about $525, permits typically $20–$150, dumpster rental $300–$475 a week, roof repair after stack removal $375–$1,800, and demolition labor at $50–$100 per hour per worker. Angi's 2026 data puts load-bearing removal at $4,000–$15,000+.
Estimated cost: UK budgets differ: ground-floor breast removal typically £1,500–£3,000, full removal including the stack £2,500–£5,500, structural engineer £350–£700, building control approval £250–£600, and scaffolding £700–£2,000 on a full removal.
The forum verdict is blunt: on AVForums the repeated advice is that building around the breast is cheaper by far, and the money is better spent on AV gear. One member who did remove theirs called the mess "unreal" — and still said it was right for their layout. It comes down to whether the breast genuinely ruins the room or merely inconveniences your design. See also our complete media wall price breakdown.
Phase 3 checklist
- Route priced with support and making-good, not just demolition
- Permit cost confirmed locally
- Quotes gathered — compare local media wall installers or get matched for free quotes
Phase 4 — Decide what happens to the flue before you close the wall
This is the phase DIY builds skip, and it returns as a damp patch two winters later.
If the chimney stays and the fireplace is decommissioned, the flue becomes a tall, cold, unheated void behind your new wall. Seal it airtight at both ends and moisture condenses inside the masonry with nowhere to go — a failure builders on MyBuilder and MoneySavingExpert describe constantly. The remedy is a vented cap or cowl rather than a sealed slab, plus a low vent in each room that had a fireplace. Get that bottom vent on the drawing: once frame, board and fire are in, retrofitting one means cutting the wall apart.
If the stack comes down instead, borrow the UK building control rule: fill the recess left where the flues ran with brickwork of the same thickness and density as the surrounding wall — bricks on edge, tied back, fully mortared.
Important: Capping a flue airtight at both ends is the most common cause of post-project damp on a chimney breast. Vent it, or expect staining through your new plaster.
Phase 4 checklist
- Decided: flue retained and vented, or removed and the recess made good
- Vented cowl specified rather than a sealed cap, low vent in the layout
- Damper closed and sealed if an electric insert goes into the old firebox
Phase 5 — Plan heat and clearances around whatever fire you keep
Framing around a working masonry fireplace brings model code clearances into play: framing at least 2 inches from the fireplace's front faces and sides and 4 inches from the back, no combustible material within 6 inches of the opening, and within 12 inches of it no projection greater than 1/8 inch per inch of clearance. Read that last rule carefully — a chunky timber surround stepping out near a live firebox will not pass.
Heat is the other half. Flat panels are generally rated to a maximum operating temperature around 95–104°F, while installers measuring above an active wood fire report far higher wall temperatures near the mantel. That's why most chimney-breast media walls end up using an electric fire instead. Electric inserts sidestep the flue entirely — no venting, so a closed, sealed damper is fine — but carry their own clearances, commonly about 1 inch to back and sides and 2 inches from the frame to a mantel board. Follow the manual, and see our guide to electric fire heat and ventilation.
Rule of thumb: If the original firebox stays live, design the media wall to stop short of it and treat the fireplace as a separate zone. Wrapping a continuous panelled wall tight around a working firebox is where code problems start.
Phase 5 checklist
- Decided: live fireplace, electric insert, or no fire
- Code clearances checked against the framing plan if the fireplace stays live
- Electric fire chosen and its manual clearances applied
Phase 6 — Lock down structure, power and sign-off
Two professionals decide whether this goes smoothly: a structural engineer and a licensed electrician. If masonry comes out, something must carry what's above, and UK guidance has shifted sharply. Local Authority Building Control withdrew its technical guidance for gallows brackets after April 2024, and the CROSS safety reporting system explains why: historic non-hydraulic lime mortars run roughly 0.5–2 N/mm² against 4–12 N/mm² for modern mortar, so bracket fixings can't reliably resist pull-out and shear. The Institution of Structural Engineers points to designed steel beams instead. US practice lands in the same place — a load-bearing chimney needs an engineer's assessment and designed support, plus a demolition permit on file.
This build almost always means new outlets behind the TV and at the fire: our guide to what the NEC allows for outlets in a media wall covers the recessed-box rules, and the framing method matters too — see MDF vs stud.
When NOT to DIY: Removing chimney masonry, any new circuit or relocated outlet, and anything touching a live gas fireplace. Engineer, electrician, gas fitter — in that order.
Phase 6 checklist
- Structural engineer engaged if any masonry is cut or removed
- Steel beam design obtained rather than assuming brackets pass
- Permits identified and neighbor notified if the stack is shared
Decision points
Rule of thumb: If the breast projects less than roughly 12 inches and the room is a reasonable size, frame over it — the floor space demolition recovers is smaller than the cost and risk you take on.
Rule of thumb: If previous owners already removed the breast on the floors above, you have a support question rather than a demolition question — get an engineer in first.
Rule of thumb: Don't permanently lose both alcoves — experienced posters warn that filling the recesses flat makes a room read smaller and leaves nowhere sensible for curtains.
Best for: Full removal earns its cost when the breast eats a genuinely small room, when the stack is redundant and deteriorating, or when you're re-roofing anyway.
Your full pre-build checklist
- Fireplace status confirmed — live wood, live gas, or decommissioned
- Rooms above, roofline and party-wall status checked
- Asbestos testing done if the house is older
- All dimensions sketched, including firebox internal depth
- Depth gained by removal weighed against framing over
- Route chosen with support and making-good in the budget
- Flue plan decided — vented cap plus low vent, or recess bricked solid
- Code and electric fire clearances applied to the frame design
- Engineer engaged, steel specified, permits confirmed
- Licensed electrician booked and two or more quotes compared
To test a layout, plan your wall with the configurator and check the TV, fire and panel proportions against your alcove widths. To hand it over, ask for fireplace media wall installation, which covers fire, framing and making-good together. GetMediaWall is an independent directory — we list installers, we don't vet or guarantee them, so verify licensing and insurance yourself.
Sources
- Chimney and Fireplace Removal Cost — HomeAdvisor — US costs for breast-only and full removal, engineer fees, permits, dumpster, roof repair and labor rates
- How Much Does Chimney Removal Cost? — Angi — 2026 US averages and the load-bearing chimney cost band
- How Much Does It Cost to Remove a Fireplace or Chimney? — HomeGuide — partial vs full removal costs and permit requirements
- Chimney Breast Removal 2026: Options, Rules and Costs — BestBuilders — UK costs, building control fees, timelines and the resale/surveyor note
- The suitability of gallows brackets to support chimney breasts — CROSS Safety Report — LABC guidance withdrawal after April 2024, lime vs modern mortar strengths, IStructE steel beam advice
- Chimney stack removal and the building regulations — Richmond Council Building Control — support methods, gallows bracket limits, and filling the flue recess with matching brickwork
- Chimney breast — Wikipedia — uneven loading when the lower breast is removed without support above
- Fireplace clearance code provisions — UpCodes — 2 in / 4 in framing clearances, 6 in mantel rule, 1/8 in per inch projection rule, 12 in firebox lining rule
- Question - Chimney Breast: Remove or Mount? — AVForums — homeowner experience on cost, mess, structural advice and reusing the old firebox for AV gear
- Horizontally extending chimney breast for media wall — AVForums — the ~6 inch recess depth problem and heat from equipment in shallow recesses
- Chimney breast fireplace to media wall conversion lintel advice — Screwfix Community — lintel-and-batten approach adding minimal room depth
- How to ventilate and insulate a capped chimney — MyBuilder — vented cowl plus low-level room vent to prevent condensation in a disused flue
- Venting an unused chimney — MoneySavingExpert Forum — homeowner reports of damp after sealing a flue at both ends
- How To Install An Electric Fireplace Insert In An Existing Fireplace — Fireplace Universe — closed and sealed damper, rain cap, and typical insert clearances
- Mounting a TV Above a Fireplace: Heat, Height, and When to Say No — Mounting NYC — flat-panel maximum operating temperature range and measured wall temperatures above an active fire