Gas Fireplace Installation Cost Calculator
A gas fireplace adds two lines a wood one never has — a gas supply run and its direct-vent piping. Both are licensed, permitted work, and both are where the number moves.
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A gas fireplace adds a gas line and direct-vent or B-vent piping to the unit and labor — about $4,400 here. Gas work is a licensed pro’s job; enter each line from your quote.
A gas fireplace is the low-fuss option — flip a switch, get flame — but the install carries two trades a wood appliance skips. First, a gas line has to reach the unit: black iron or CSST run from the nearest supply point, and the farther and more finished the wall, the more that run costs. Second, most modern units are direct-vent, which means a sealed co-axial pipe out a sidewall or up the roof, drawing combustion air in and pushing exhaust out through the same fitting.
Both of those are permitted, inspected work in almost every jurisdiction, and gas is not a DIY line item — a licensed installer sizes the pipe, checks for leaks and terminates the vent to the listed clearances. This tool keeps the gas line and the venting on their own rows so a 40-foot gas run in a finished basement does not hide inside a vague "labor" figure.
Formula
total = (unit + gas_line + venting + add_ons + labor) × (1 + contingency)
The two lines that separate a gas job from a wood one are called out on purpose. gas_line scales with distance and difficulty — a short stub off an existing manifold is cheap, a long run fished through finished walls is not. venting is the co-axial pipe and its termination cap. Everything else — the unit, the media and remote, the finish, the fan — is add-ons and labor.
Worked example
Direct-vent gas fireplace on an exterior living-room wall. Unit at $2,380, a 35-ft gas run fished from the utility room at $620, co-axial vent through the sidewall at $540, no extras, and labor to set, plumb and commission at $1,050. With a 10% buffer:
(2,380 + 620 + 540 + 0 + 1,050) × 1.10 = 4,590 × 1.10 = $5,049
Shorten that gas run to a 10-ft stub off a nearby line and you shave a few hundred dollars — the run length is the swing factor.
Gas-specific things that move the price
- Gas run distance. The single biggest variable. A stub off a nearby manifold is minor; a long fished run through finished walls, or an upsized meter/regulator, is real money.
- Vent type. Direct-vent (sealed, sidewall or roof) is the common modern choice. B-vent needs a vertical flue. Vent-free skips the pipe but is banned or restricted in many areas — check local code first.
- Fuel. Natural gas vs propane changes the orifice and sometimes the regulator; a propane job with a new tank/line is a bigger scope.
- Permit and inspection. Gas work is permitted and leak-tested. Budget the permit and do not let anyone talk you out of the inspection.
Standards for gas hearth appliances and venting sit with NFPA and the HPBA; the actual clearances come from the unit’s listing.
Reference table
Labeled planning band — sanity check only, NOT a quote. Gas work must be permitted; confirm with a licensed installer.
| Job | Typical band |
|---|---|
| Fireplace installation | $1,500 – $8,000 |
Frequently asked questions
Why is the gas line a separate cost?
Because it varies more than anything else on the job. A short stub off an existing gas manifold is a small charge; a long black-iron or CSST run fished through finished walls — or a meter/regulator upgrade to carry the load — can rival the appliance. Breaking it out keeps that swing visible.
Do I need a chimney for a gas fireplace?
Not a masonry chimney. Most modern gas units are direct-vent: a sealed co-axial pipe out a sidewall or up through the roof handles both intake and exhaust. B-vent models need a vertical flue; vent-free models use no pipe but are restricted or prohibited in many jurisdictions — confirm local code.
Can I install a gas fireplace myself?
The gas connection, no. Sizing and leak-testing a gas line and terminating the vent to listed clearances is licensed, permitted, inspected work. You might handle framing or facing, but the gas and vent commissioning belong to a qualified installer.
Is a gas fireplace cheaper to install than wood?
Often the appliance and labor are comparable, but gas adds the gas line and its venting while wood adds a full flue liner or class-A pipe. Which wins depends on how far the gas has to travel and how tall the wood venting is — run both estimators and compare.