Do I Need a Permit to Replace a Furnace in New Mexico?
Quick Answer
Yes — even a like-for-like furnace swap requires a mechanical permit.
Why Even a Swap Needs a Permit
Furnace replacements involve gas connections, venting, and combustion air — all safety-critical systems. Most jurisdictions require a mechanical permit to verify the new furnace is properly vented, has adequate combustion air, and the gas connections are leak-free. This is true even for exact same-model replacements.
High-Efficiency Conversions
Upgrading from a standard-efficiency (80%) to high-efficiency (90%+) furnace changes the venting requirements: standard units use metal B-vent, high-efficiency units use PVC/CPVC. The old metal vent chase may need to be sealed. A condensate drain line is also required for high-efficiency units.
What Inspectors Check
The final inspection covers: gas piping and drip leg, venting type and clearances, combustion air supply (especially in confined spaces), condensate drain (high-efficiency units), thermostat operation, and CO detector presence on every level.
Bundled with AC?
If you're replacing both the furnace and AC unit at the same time, one mechanical permit typically covers both. The inspector will check the AC refrigerant lines, electrical disconnect, and condenser pad in addition to the furnace items.
Bottom Line
Yes, always. The permit is $40-$75 and your HVAC contractor handles it. One final inspection. Don't skip it — CO poisoning from bad venting is real.
Permit fees by city in New Mexico
Verified from each city’s published fee schedule. Where a city has no separate fee listed for this project, open the city page for the current requirements and amount.
| City | Permit fee | Source |
|---|---|---|
| Alamogordo | $37.50Verified | Mechanical / HVAC Permit → |
| Albuquerque | $23.50 minimum for valuation $1–$2,000; then $23.50 for the first $500 plus $3.05 per additional $100 (to $2,000); $69.25 for the first $2,000 plus $14.00 per additional $1,000 (to $25,000); $391.75 for the first $25,000 plus $10.10 per additional $1,000 (to $50,000); $643.75 for the first $50,000 plus $7.00 per additional $1,000 (to $100,000); $993.75 for the first $100,000 plus $5.60 per additional $1,000 thereafter — modifier of 0.50 applied to the resulting valuation for one- and two-family dwellingsVerifiedvia Residential Building Permit (New Construction) | Residential Building Permit (New Construction) → |
| Clovis | Same Type I valuation table used city-wide: e.g. $28.00 + $5.60 per $1,000 for $2,000–$25,000 valuationVerified | Residential Mechanical / HVAC Permit → |
| Farmington | See city page for the current Residential Mechanical / HVAC Permit fee | Residential Mechanical / HVAC Permit → |
| Hobbs | $20.00Verified | Residential Mechanical / HVAC Permit → |
| Las Cruces | $150.00Verified | Residential Mechanical / HVAC Permit → |
| Rio Rancho | $11.00 eachVerified | Residential Mechanical / HVAC Permit → |
| Roswell | $24.00Verifiedvia Residential Building Permit | Residential Building Permit → |
| Santa Fe | $40.00 per permitVerified | Mechanical / HVAC Permit → |
| Unincorporated Bernalillo County | $23.50 eachVerified | Mechanical / HVAC Permit → |