Gas Fireplace Installation Cost: $2,300–$8,000 (Average $3,700) in 2026

How much does it cost to install a gas fireplace?

Installing a gas fireplace insert into an existing fireplace and chimney costs $2,300 to $8,000, averaging around $3,700 (HomeAdvisor). Bob Vila, citing Angi, reports a nearly identical picture: $700 to $6,500, averaging $3,600. Those two sources agree closely because they’re both pricing the same, most-common scenario — swapping an old wood-burning or gas setup for a new insert using the chimney you already have. HomeGuide’s numbers run higher, averaging $6,200 across a range of $2,300 to $10,000, because its data also folds in larger installs and pricier finishes. Fixr’s average is highest of all, $9,084 (range $3,558-$14,609), because its scope explicitly includes full custom-built fireplaces constructed where none existed before — a fundamentally bigger job than fitting an insert into a firebox that’s already there.

Insert, built-in, or log set — and direct-vent vs. ventless — which costs more?

Scope is the single biggest cost driver here. A gas fireplace insert, which slides into an existing firebox and reuses the chimney, runs $2,000 to $5,000 installed (HomeGuide). A freestanding gas log set or unit, which needs only a gas hookup and no existing fireplace, costs $579 to $10,000 depending on style (Fixr). Building a true built-in fireplace where none existed — framing the firebox, running new gas and possibly electrical lines, and adding a flue — costs $8,450 to $26,816 (Fixr), several times the price of a simple insert swap. Venting matters just as much: direct-vent units, which exhaust combustion byproducts outside through a sealed system, cost $4,300 to $11,200 (HomeAdvisor, Bob Vila), while ventless (unvented) units skip that system entirely and cost less, $1,500 to $4,600 (HomeAdvisor, Bob Vila) — though ventless models are restricted or banned outright in some states, so confirm local rules before you buy one.

What do the gas line, surround, and permit add to the total?

Gas line work is often the line item homeowners forget to budget for. If no gas line currently reaches the fireplace location, running a new one costs $15 to $50 or more per linear foot, or $350 to $2,000 for the full run (HomeGuide); Bob Vila cites a similar rate of about $25 per linear foot. If a line is already nearby, extending it is cheaper — $250 to $500 (HomeGuide). Surround material is the next biggest swing factor: metal and concrete surrounds start around $9 to $50 per square foot, while stone and marble can run $150 to $300 per square foot (Bob Vila, HomeGuide). A separate mantel adds $500 to $5,000 depending on the material (HomeGuide, Fixr), and a glass fireplace door adds $600 to $2,000 (HomeGuide). Most jurisdictions also require a permit, typically $100 to $500, though many installers bundle this into their labor quote rather than itemizing it (HomeGuide, HomeAdvisor).

How can you keep gas fireplace installation costs down?

• Choose an insert over a built-in if you already have a working fireplace and chimney. Reusing the existing firebox and flue keeps costs in the $2,300 to $8,000 range instead of $8,450-plus for new construction (HomeAdvisor, Fixr).
• Confirm whether a gas line already reaches the install location before you fall in love with a fireplace placement — extending an existing line ($250-$500) is far cheaper than running a brand-new one ($350-$2,000 or more) (HomeGuide).
• Weigh ventless against direct-vent carefully. Ventless saves $2,000-plus up front (HomeAdvisor, Bob Vila), but check your state and local codes first, since some areas restrict or ban unvented units.
• Keep the surround simple. Metal, tile, or concrete surrounds run a fraction of what stone or marble cost per square foot (Bob Vila, HomeGuide), and you can always upgrade the facing later without touching the fireplace itself.
• Get several local quotes and ask what’s included — permits, the gas line run, and the surround are sometimes itemized separately and sometimes bundled, which makes bids hard to compare at a glance.

Prices vary by region, existing infrastructure, and how much of the job is new construction versus reusing what’s already there, so treat the figures above as a planning budget. If you’re deciding between a gas insert and other heating appliances, it’s worth comparing pellet stove installation and gas line installation costs separately, since either could change your total. Get two or three local quotes, and confirm whether the gas line, surround, and permit fees are included, before committing to a final number.