Union County, NM: Tiny Homes Allowed | Building Permits & Zoning

Unincorporated Union County, New Mexico requires state permits for covered residential construction, with the New Mexico Construction Industries Division serving as the permitting authority^1,2. Septic permits and inspections come from the New Mexico Environment Department^3,4. We could not confirm a current countywide zoning ordinance, so ask Union County about parcel-specific land-use limits before buying or designing a project⁵.

At a glance

Building permit: Required before covered work begins; separate permits apply to building and regulated trades^1,2
Zoning: Countywide zoning status could not be confirmed; ask Union County about the parcel before relying on a proposed use⁵
Septic permit: Required before installing or modifying an onsite system; apply through the New Mexico Environment Department^3,4
RV living: Long-term occupancy on private land could not be confirmed; ask Union County before placing or occupying an RV⁵
Tiny home: A code-compliant tiny house on a permanent foundation is allowed under state rules; local placement rules remain unconfirmed⁶
Manufactured home: A state installation permit and final inspection are required; local placement rules may also apply⁷
Owner-builder: A conditional homeowner permit is available for an owner’s primary residence, with limits on who performs and supervises the work^2,8

Who to call

Building permits

New Mexico Construction Industries Division

State building permits and construction-code administration for unincorporated Union County

(505) 476-4700

2550 Cerrillos Road – 3rd Floor, Santa Fe, New Mexico 87505

Septic permits

New Mexico Environment Department Onsite Wastewater Program

Onsite liquid-waste permit applications submitted to the local NMED field office

505-827-2855

One more officePlanning & zoning

Planning & zoning

Union County

Parcel-specific questions about county land use, subdivision status and local requirements

575.374.8896 ext 4

200 Court Street, PO Box 430, Clayton, NM 88415

Contact details are copied from each office’s official page and were checked against it on October 5, 2026.

Do you need a building permit in Union County, New Mexico?

Yes.

Yes. Covered building, structural, electrical, plumbing, mechanical and LP-gas work in unincorporated Union County requires the applicable permit before work begins, unless a statute or rule provides an exception². Limited residential exceptions include certain one-story detached storage buildings no larger than 120 square feet and fences no higher than 6 feet, but regulated trade work may still need its own permit⁸. Covered residential construction follows New Mexico's amended 2021 International Residential Code⁹. Permitted work must pass foundation, slab or under-floor, frame, weather-barrier and final inspections as applicable, and all electrical wiring requires a permit and inspection^8,10. Union County does not issue these state construction permits; CID serves the county's unincorporated areas¹.

Who issues building permits in Union County, and how do you reach them?

The New Mexico Construction Industries Division issues residential building permits for Union County's unincorporated areas.

The New Mexico Construction Industries Division issues residential building permits for Union County's unincorporated areas¹. CID's Santa Fe office is at 2550 Cerrillos Road and can be reached at (505) 476-4700¹¹. Applicants submit the form approved for each permit type, with separate permits for general building, electrical, mechanical or plumbing, and LP-gas work². A homeowner building application requires county planning and zoning approval, two complete plan sets, the Multi-Purpose State Building Application and the CID-provided fee¹⁰. CID calculates that fee after receiving the total project cost and does not process the request until payment¹⁰. CID says it will issue an approved complete package within five working days¹⁰.

Does Union County, New Mexico have zoning?

We could not confirm whether Union County currently applies countywide zoning in unincorporated areas.

We could not confirm whether Union County currently applies countywide zoning in unincorporated areas⁵. New Mexico law permits counties to zone territory outside municipal zoning jurisdiction, but that authority does not prove Union County has adopted an operative zoning ordinance¹². Union County regulates land division under Ordinance 21-1997, although the applicable subdivision category, plat procedure, terrain, floodplain, road, access provisions and later amendments require parcel-specific confirmation¹³. Before treating a parcel as suitable for a house, RV, business, agricultural building or second dwelling, ask Union County at 575.374.8896 ext 4 for its land-use status, subdivision history and applicable setbacks¹⁴. Land inside a municipality may be subject to municipal rules rather than county rules¹².

How do septic permits work in Union County?

The New Mexico Environment Department handles onsite liquid-waste permits in Union County because Bernalillo County is the state's only county with its own onsite-wastewater ordinance.

The New Mexico Environment Department handles onsite liquid-waste permits in Union County because Bernalillo County is the state's only county with its own onsite-wastewater ordinance⁴. Applications go to the local NMED field office for review³. Apply before installing or modifying a system; the package includes ownership proof, a site diagram, a floorplan and a plat or survey when applicable, with payment due after approval or conditional approval³. Request inspection 48 hours, or two business days, in advance and do not cover the system³. Only 30.8% of Union County soils are rated without severe limitations for a conventional drain field, so make site evaluation an early contingency¹⁵. Call 505-827-2855 to identify the correct field office³.

Can you live in an RV or tiny home on land in Union County?

We could not confirm a Union County rule allowing long-term RV occupancy or temporary camping on private land, so ask Union County about the exact parcel before moving an RV onto it.

We could not confirm a Union County rule allowing long-term RV occupancy or temporary camping on private land, so ask Union County about the exact parcel before moving an RV onto it^5,14. New Mexico treats a tiny house on a chassis with its permanent axle as an RV subject to RV codes and licensing, while a tiny house placed on a permanent foundation may qualify as a dwelling under the state residential code⁶. A qualifying permanent-foundation tiny house may contain no more than 400 square feet of floor area excluding lofts and must provide complete independent living facilities⁶. State building compliance does not answer unresolved county placement, setback or minimum-lot questions⁵.

Building a home in Union County: the steps, in order

Ask Union County to confirm the parcel's land-use status, subdivision history and any local setbacks before design.

Ask Union County to confirm the parcel's land-use status, subdivision history and any local setbacks before design^5,13.

Submit the CID application, two complete plan sets, county planning and zoning approval and the CID-provided fee; arrange separate permits for regulated trades¹⁰.

If acting as owner-builder, sign and notarize the responsibilities form; the permit is limited to the owner's primary residence, and licensed subcontractors obtain their own permits^2,8.

Apply to the local NMED field office with the septic site documents, then pay after approval or conditional approval³.

Notify CID when permitted work is ready, provide access and complete the required building and trade inspections^8,16.

Obtain inspector approval before connecting or reconnecting regulated plumbing to a water source or sewer system¹⁶.

Do not occupy the building until the inspector issues a certificate of occupancy or approved final inspection, as applicable¹⁶.

What should you check before buying land in Union County?

Start with water and septic feasibility.

Start with water and septic feasibility. Union County averages 16.2 inches of precipitation annually, and severe drought has occurred in 46.8% of years¹⁵. Because only 30.8% of soils avoid severe conventional drain-field limitations, make the septic site evaluation part of due diligence rather than a post-closing task¹⁵. The terrain is generally gentle, with 91.1% of land at a slope of 15% or less, but parcel-level drainage and flood exposure still matter¹⁵. Union County regulates subdivision, but the current detailed lot, plat, road and access requirements could not be confirmed from the published ordinance listing¹³. Before closing, ask Union County about recorded subdivision status and legal access, and ask NMED which field office will review the septic site^3,14. We could not confirm Union County's current private-well or floodplain-development process.

Watch-outs

Union County's current zoning status, setbacks, minimum home size and long-term RV rules could not be confirmed; ask the county about the specific parcel before purchase or placement⁵.
A homeowner permit is limited to the owner's primary residence, requires meaningful owner work or paid W-2 employees, and requires licensed contractors to permit and pass inspection on subcontracted work².
Do not cover an onsite liquid-waste system before NMED inspection³.

Sources

16 official pages, each quoted and re-checked · written October 5, 2026

Written October 5, 2026 from the rules quoted below, each taken from an official source and re-checked by an independent reviewer. This is research, not legal advice: rules change, so confirm with the office before you buy or build.

Off-grid gear

Going off-grid in Union County means bringing your own water and power. The kit we’d start with:

These are affiliate links — we may earn a commission, at no cost to you. As an Amazon Associate, Bolthole Index earns from qualifying purchases.

Compared with neighboring counties

Like all 6 of its neighbors, Union County requires a building permit for a home.

Rule	Union County	Harding County	Colfax County	Mora County	Quay County	San Miguel County	Curry County
Building permit	Required	Required	Required	Required	Required	Required	Required
County zoning	Not published	Not published	Yes	Yes	No	Yes	No
Septic permits	NM Env. Dept.	NM Env. Dept.	NM Env. Dept.	NM Env. Dept.	NM Env. Dept.	NM Env. Dept.	NM Env. Dept.

Cities and towns in Union County

Inside a city or town, that city usually issues building permits and sets zoning; the county’s rules above cover unincorporated land. Septic, wells and floodplain rules usually stay with the county or state everywhere.

Town of Clayton · Village of Des Moines · Village of Folsom · Village of Grenville

Answers from the rulebook for Union County

What the ordinances and state agencies actually say — one answer per question, each quoted from the official source and independently re-checked.

Union County rules

Subdividing landRegulated (with conditions)
Subdivision of land in Union County under the county subdivision ordinance.
- The official county ordinances page lists Ordinance 21-1997 as the Subdivision Ordinance.
- The New Mexico State Records Center and Archives identifies Union County Subdivision Regulations adopted by Ordinance No. 21-1997 and filed July 2, 1997.
- The operative ordinance text and any later amendments were not fully extracted.
“Ordinance 21-1997 - Subdivision Ordinance (PDF)”
Ordinances ↗Re-checked Sep 26, 2026
2 more reviewed findings on this topic
- Regulated (with conditions) — Subdivision of land subject to Union County Ordinance 21-1997.
  “Ordinance 21-1997 - Subdivision Ordinance (PDF)”
  Ordinances | Union County, NM ↗Re-checked Oct 3, 2026
- Regulated (with conditions) — Subdivision activity in Union County.
  “Ordinance 21-1997 - Subdivision Ordinance (PDF)”
  Ordinances | Union County, NM ↗Re-checked Oct 4, 2026

New Mexico rules that apply here

Building permitRequired
Buildings and structures regulated by the New Mexico Residential Code, including residential construction, alterations, repairs, additions, moves, improvements, removals, conversions, and demolitions, and state-administered commercial construction.
- A permit must be obtained before covered work begins.
- Residential exceptions include one-story detached accessory buildings used as tool or storage sheds, playhouses, and similar uses not exceeding 120 square feet; fences not over 6 feet high; specified retaining walls; certain water tanks, sidewalks, driveways, finish work, shallow prefabricated pools, playground equipment, window awnings, and detached decks.
- Unless otherwise exempted, separate plumbing, electrical, and mechanical permits may still be required for otherwise exempted residential work.
- Commercial applicants must be validly licensed with the appropriate license classification, submit the state building permit application, obtain any required city or county zoning approval, and pay the valuation-based fee before permit issuance.
residential accessory-building exemption floor area: <= 120 square feet (One-story detached accessory buildings used as tool and storage sheds, playhouses, and similar uses.) · fence exemption height: <= 6 feet · water-tank exemption capacity: <= 5000 gallons (Height-to-diameter or width ratio must not exceed 2:1.) · detached-deck exemption area: <= 200 square feet (Deck must not be more than 30 inches above grade, must not be attached to a dwelling, and must not serve the required exit door.)
“Except as specified in Section 105.2 IRC, no building or structure regulated by this code shall be erected, constructed, enlarged, altered, repaired, moved, improved, removed, converted, or demolished unless a permit has first been obtained from the building official.”
Building Permit Guide for Residential Construction ↗Re-checked Sep 12, 2026
2 more reviewed findings on this topic
- Required — Building, structural, electrical, plumbing, mechanical, and LP-gas work subject to CID jurisdiction in Union County.
  “Subject to the Construction Industries Licensing Act “CILA”, Sections 60-13-3 and Section 60-13-45 NMSA 1978, and its rules, no building or structure shall be erected, constructed, enlarged, altered, repaired, moved, improved, removed, converted or demolished, no electrical wiring, plumbing or mechanical work or LP gas work as defined and described in the applicable New Mexico construction codes for those trades, may be installed, repaired, altered or maintained in or on such building or structure, unless the applicable permit has first been obtained from the appropriate AHJ, unless otherwise provided by statutes or rule.”
  14.5.2 NMAC — Permits ↗Re-checked Oct 2, 2026
- Required — Buildings and structures regulated by the New Mexico Residential Code in Union County.
  “Except as specified in Section 105.2 IRC, no building or structure regulated by this code shall be erected, constructed, enlarged, altered, repaired, moved, improved, removed, converted, or demolished unless a permit has first been obtained from the building official.”
  Building Permit Guide for Residential Construction ↗Re-checked Oct 4, 2026
Owner-builder exemptionConditional
A New Mexico property owner constructing or altering the owner’s single-family primary residence, including permitted appurtenant structures, under a homeowner’s permit.
- The exemption is limited to construction or alteration of the owner’s primary residence; other use cancels the current permit and can result in denial of later homeowner permits.
- The homeowner must comply with CILA, NMAC rules, applicable standards and codes, and may act as the general contractor only when the major portion of the work, based on dollar amount, is completed by the homeowner.
- A permit is required for all construction-related work for which a permit is required by statute or rule; the rule does not exempt the owner-builder from state permitting or inspections.
- Homeowner permits are limited to single-family dwellings and appurtenant structures such as private garages, carports and sheds, require proof of ownership, and are subject to AHJ approval.
- The application requires an AHJ-approved application, signed and notarized responsibility sheet, acknowledgement of the homeowner-permit instructions, local zoning approval, floodplain determination, proof of identity and ownership, and payment of required fees.
- Separate homeowner permits may be issued for general building construction, mechanical/plumbing and electrical work; each is limited to the primary residence and does not apply to rental property, other owned property, or commercial work or property.
- The homeowner is responsible for requesting inspections, correcting code violations, and requesting re-inspections for a certificate of occupancy or final inspection. Subcontractors remain responsible for permits, inspections and corrections for plumbing, mechanical and electrical work they perform.
- The homeowner may perform authorized work personally or with W-2 employees, or subcontract part of the work while self-performing a significant portion. Subcontracted work must be performed by licensed contractors who obtain their own permits and pass required inspections.
- A homeowner permit is invalid for a project managed, supervised or acted on as general contractor by a GB-2 or GB-98 contractor; that contractor must obtain the appropriate permits and assumes responsibility for the site work.
- Single-scope projects such as roofing or window installation are ineligible when subcontracted and not performed by the homeowner or valid W-2 employees.
- Plumbing requires sufficient knowledge as determined by the TBC or CBO; a written examination with a minimum passing score of 75% may be required, failed examinations may not be repeated sooner than 30 days, and permitted plumbing work must be performed by the permittee.
- Electrical work requires approved plans or drawings and a CID homeowner electrical exam with a minimum passing score of 75%; failed examinations may not be repeated sooner than 30 days, and permitted electrical work must be performed by the permittee.
- A homeowner permit may not be issued for HVAC, natural gas or LP gas installations. HVAC and natural-gas work requires a properly licensed contractor and AHJ permitting and inspection; LP-gas work requires a properly licensed contractor and permitting and inspection through the LP gas trade bureau.
- A homeowner-permit project may not be placed on the market for sale while under construction; doing so automatically voids the permit and may lead to unlicensed-contracting charges.
- No more than one homeowner permit for a single-family dwelling may be issued to the same property owner within any 12-month period.
- The cited rule section states an adoption/replacement date of March 10, 2022.
homeowner electrical exam minimum passing score: >= 75 percent (Required after plan approval for issuance of a homeowner electrical permit.) · homeowner plumbing exam minimum passing score: >= 75 percent (The TBC or CBO may require the written examination.) · failed homeowner exam retest interval: >= 30 days (Failed plumbing and electrical examinations may not be repeated sooner.) · homeowner permits per single-family dwelling and property owner: <= 1 per 12 months
“A homeowner permit allows homeowners to obtain permits for constructing or altering their primary residence without becoming a licensed contractor is strictly limited to construction and alteration of their primary residence. Any other use of a homeowner’s permit shall result in cancellation of the current homeowner permit and denial of any subsequent request for a homeowner permit. The homeowner licensing exemption requires conformity with CILA, its rules, standards and codes. This includes a homeowner acting as a general contractor for the project. The homeowner’s permit authorizes the homeowner to physically perform the work, alone or with legal employees, or act as a general contractor and subcontract portions of the work to licensed contractors. In order to qualify for the homeowner permit the major portion of the work to be performed, based on dollar amount, must be completed by the homeowner. A homeowner’s permit may only be issued to a property owner and only for the property owner’s primary residence occupied or intended to be occupied by the homeowner.”
14.5.2 NMAC — Permits ↗Re-checked Oct 4, 2026
3 more reviewed findings on this topic
- Conditional — Homeowner construction permits for residential work in Union County.
  “A homeowner's permit may not be used to permit a project where a GB-2 or GB-98 contractor is acting as a general contractor on the project. Any contractor acting as a general contractor on a project where there is a Homeowner’s permit must obtain a building permit for his work, and shall be held responsible for any work, performed at this site. Further, licensed subcontractors will be held responsible for their work, which also must be permitted separately. A homeowner may not perform electrical, plumbing, or mechanical work unless the homeowner applies for and passes the required CID exam for such work.”
  Building Permit Guide for Residential Construction ↗Re-checked Sep 26, 2026
- Conditional — Homeowner permits for a primary residence in Union County under CID jurisdiction.
  “A homeowner may apply for a homeowner’s building, plumbing or electrical permit to construct a residence or to remodel or construct an addition to an existing residence. A homeowner’s permit may only be issued to a property owner and only for the property owner’s primary residence occupied or intended to be occupied by the homeowner.”
  14.5.2 NMAC — Permits ↗Re-checked Oct 2, 2026
- Available (with conditions) — A homeowner seeking a New Mexico homeowner construction permit for a residence in Union County.
  “The qualifying party for the licensed contractor requesting the permit or the homeowner requesting a homeowner construction permit must sign the application.”
  Building Permit Guide for Residential Construction ↗Re-checked Oct 4, 2026
Building code adoptedAdopted (with conditions)
Commercial construction, alteration, relocation, enlargement, replacement, repair, equipment, use and occupancy, location, removal, and demolition of buildings or structures in New Mexico subject to the jurisdiction of the Construction Industries Division.
- The 2021 New Mexico Commercial Building Code applies on or after July 14, 2023.
- The rule does not apply when performed pursuant to a permit for which an application was received by CID before July 14, 2023.
- Detached one- and two-family dwellings and multiple single-family dwellings (townhouses) not more than three stories high with separate means of egress, and their accessory structures, must comply with the 2021 New Mexico Residential Building Code instead.
- Existing buildings not subject to the residential code undergoing a change of occupancy, repair, alteration, or addition must comply with either the commercial building code or the existing building code, as applicable.
- The rule adopts the 2021 International Building Code by reference, as amended by the rule.
effective date: 2023-07-14 (unless a later date is cited at the end of a section) · adopted reference code: 2021 International Building Code (as amended by 14.7.2 NMAC)
“14.7.2.5 EFFECTIVE DATE: July, 14, 2023, unless a later date is cited at the end of a section. [...] 14.7.2.8 ADOPTION OF THE 2021 INTERNATIONAL BUILDING CODE: A. This rule adopts by reference the 2021 International Building Code, as amended by this rule.”
Rules, Laws, and Building Codes ↗Re-checked Sep 11, 2026
5 more reviewed findings on this topic
- Adopted (with conditions) — Construction subject to the New Mexico Construction Industries Division, including residential construction in Union County where CID is the authority having jurisdiction.
  “This rule adopts by reference the 2021 International Residential Code, as amended by this rule.”
  14.7.3 NMAC — 2021 New Mexico Residential Building Code ↗Re-checked Oct 2, 2026
- Adopted (with conditions) — Construction subject to the New Mexico Building Code, including construction in Union County where state CID is the authority having jurisdiction.
  “This rule adopts by reference the 2021 International Residential Code, as amended by this rule.”
  Construction Industry | Frequently Asked Questions | NM RLD ↗Re-checked Oct 3, 2026
- Adopted — Residential construction in New Mexico, including Union County where state CID jurisdiction applies.
  “The Construction Industries Division currently enforces the following codes: • 2021 New Mexico Commercial & Residential Building Code • 2021 International Building Code • 2021 International Residential Code”
  Building Permit Guide for Residential Construction ↗Re-checked Oct 4, 2026
- Adopted (with conditions) — Detached one- and two-family dwellings, multiple single-family dwellings (townhouses) not more than three stories high with separate means of egress, and their accessory structures in New Mexico subject to the jurisdiction of the Construction Industries Division.
  “14.7.3.5 EFFECTIVE DATE: July 14, 2023, unless a later date is cited at the end of a section. From the date of publication of this rule in the New Mexico register, until December 14, 2023, permits may be issued under either the previously adopted rule, or this rule. After December 14, 2023, permits may be issued only under this rule. [...] A. This rule adopts by reference the 2021 International Residential Code, as amended by this rule.”
  Rules, Laws, and Building Codes ↗Re-checked Sep 11, 2026
- Adopted — Residential construction in New Mexico subject to the jurisdiction of the Construction Industries Division, including detached one- and two-family dwellings, qualifying townhouses, and their accessory structures.
  “This rule adopts by reference the 2021 International Residential Code, as amended by this rule.”
  14.7.3 NMAC — 2021 New Mexico Residential Building Code ↗Re-checked Oct 5, 2026
InspectionsRequired
Residential construction subject to CID inspection in Union County.
- Required inspections include foundation, concrete slab or under-floor, frame, weather-resistive barrier, and final inspection.
- Final electrical, plumbing, and mechanical inspections must occur before final general construction inspection.
- The construction inspector may require other inspections.
- Inspection requests are made by email or telephone to CID.
“REQUIRED INSPECTIONS To request an inspection e-mail us at CID.lnspection@state.nm.us or call 505-222-9813 or 877-243-0979 1. FOUNDATION INSPECTION. To be made after excavations for footings are complete and any required reinforcing steel is in place.”
Building Permit Guide for Residential Construction ↗Re-checked Sep 26, 2026
4 more reviewed findings on this topic
- Required — Work subject to CID jurisdiction for which a permit is issued in Union County.
  “All work for which a permit is issued must be inspected.”
  14.5.3 NMAC — Inspections ↗Re-checked Oct 2, 2026
- Required — Electrical wiring work in New Mexico, including Union County.
  “Yes, all wiring requires a permit and inspection.”
  Construction Industry | Frequently Asked Questions | NM RLD ↗Re-checked Oct 3, 2026
- Required — State-regulated residential construction in Union County.
  “REQUIRED INSPECTIONS To request an inspection e-mail us at CID.lnspection@state.nm.us or call 505-222-9813 or 877-243-0979”
  Building Permit Guide for Residential Construction ↗Re-checked Oct 4, 2026
- Required — State-administered residential and commercial construction requiring building permits.
  “REQUIRED INSPECTIONS To request an inspection e-mail us at CID.lnspection@state.nm.us or call 505-222-9813 or 877-243-0979”
  Building Permit Guide for Residential Construction ↗Re-checked Sep 12, 2026
Certificate of occupancyLimited
Contracting work performed in New Mexico that is subject to Construction Industries Division jurisdiction; for occupancy of a building or portion of a building on which construction has been undertaken.
- The rule applies to CID-jurisdiction contracting work performed after March 10, 2022, unless performed under a permit whose CID application was received before that date.
- Occupancy requires either a certificate of occupancy or an approved final inspection, as applicable.
- A C/O cannot be issued until all required inspections have been performed and the appropriate inspectors have approved the work.
- For a residence constructed under a homeowner's permit, a C/O for new construction or an approved final inspection for a remodel must expressly state that the residence was constructed or remodeled pursuant to a homeowner permit.
- A temporary C/O may be issued for 30 days or more only with TBC or CBO approval, when the AHJ's analysis finds it appropriate and life, safety, or health will not be adversely affected; a written request, good cause, and an existing valid temporary C/O are required for an extension, which may not exceed 12 months.
- A C/O or approved final inspection is invalid until code violations discovered afterward are corrected and the C/O is re-issued or final inspection approved; it does not certify compliance with requirements of other regulatory agencies.
- The general construction TBC or issuing AHJ CBO may suspend or revoke a C/O or reverse an approved final inspection if it was issued in error or based on incorrect information, or if the work violates applicable New Mexico construction code, CILA, or its rules.
- Reinstatement requires appropriate CBO approval and payment of any fee assessed under 14.5.5 NMAC or local ordinance.
temporary C/O initial period: >= 30 days (Only if approved by the TBC or CBO and the AHJ finds it appropriate without adverse life, safety, or health effects.) · temporary C/O extension maximum: <= 12 months (Requires written extension request and good cause for a current, valid temporary C/O.)
“No building, or portion thereof, on which construction has been undertaken shall be occupied until the appropriate inspector has issued a C/O or an approved final inspection, as applicable.”
14.5.3 NMAC — Inspections ↗Re-checked Nov 4, 2026
3 more reviewed findings on this topic
- Required — Buildings or portions of buildings on which construction subject to CID jurisdiction has been undertaken in Union County.
  “No building, or portion thereof, on which construction has been undertaken shall be occupied until the appropriate inspector has issued a C/O or an approved final inspection, as applicable.”
  14.5.3 NMAC — Certificates of occupancy or final inspection ↗Re-checked Oct 2, 2026
- Required — Buildings and structures subject to the New Mexico Residential Code in Union County.
  “No building or structure shall be used or occupied, and no change in the existing occupancy classification of a building or structure or portion thereof shall be made until the building official has issued a certification of occupancy as provided.”
  Building Permit Guide for Residential Construction ↗Re-checked Oct 4, 2026
- Required — Buildings constructed under work subject to the jurisdiction of the Construction Industries Division (CID); occupancy requires a certificate of occupancy (C/O) or approved final inspection.
  “no building, or portion thereof, on which construction has been undertaken shall be occupied until the appropriate inspector has issued a c/o or an approved final inspection, as applicable.”
  14.5.3 NMAC Inspections (State Records Center, effective 3/10/2022) ↗Re-checked Nov 6, 2026
Minimum dwelling sizeSpecified
Lofts used as sleeping or living space in a tiny house constructed in New Mexico or transported into New Mexico and subject to CID jurisdiction.
- The tiny-house rule defines a tiny house as a dwelling of 400 square feet or less excluding lofts and excluding recreational vehicles.
- The loft must be used as sleeping or living space.
- Portions of a sloping-ceiling loft measuring less than 3 feet from finished floor to finished ceiling do not count toward the minimum area; under a gable roof with a minimum 6:12 slope, portions measuring less than 16 inches do not count.
- A tiny house on a chassis with a permanent axle is a recreational vehicle while the axle remains in place; if axles are removed and the unit is placed on a foundation, it must comply with tiny-house code requirements for a permanent foundation.
minimum loft floor area: >= 35 square feet (For a loft used as sleeping or living space.) · minimum loft horizontal dimension: >= 5 feet (For a loft used as sleeping or living space.)
“Lofts shall have a floor area of not less than 35 square feet (3.25 m2).”
14.7.3 NMAC — 2021 New Mexico Residential Building Code ↗Re-checked Nov 4, 2026
Building heightSpecified
Detached one- and two-family dwellings, multiple single-family dwellings (townhouses) with separate means of egress, and their accessory structures subject to the New Mexico Construction Industries Division residential code.
- The cited residential code applies to construction performed in New Mexico on or after December 14, 2023.
- The construction must be subject to the jurisdiction of the Construction Industries Division.
- The code scope is limited to dwellings and townhouses not more than three stories high; construction outside the NMRBC scope may be subject to the New Mexico Commercial Building Code.
- The rule states an effective date of July 14, 2023, with permits issuable under either rule until December 14, 2023, and only under the new rule after December 14, 2023.
maximum stories within NMRBC scope: <= 3 stories (The provision describes the scope of the residential code and is not a general zoning-height limit for every land use.)
“dwellings and multiple single-family dwellings (townhouses) not more than three stories high with separate means of egress”
14.7.3 NMAC — 2021 New Mexico Residential Building Code ↗Re-checked Oct 5, 2026
Tiny homesAllowed (with conditions)
Tiny houses used as single dwelling units with complete independent living facilities and placed on a permanent foundation statewide in New Mexico.
- The unit must provide permanent provisions for living, sleeping, eating, cooking, and sanitation.
- The tiny house must comply with the New Mexico Residential Code and Appendix AQ.
- Tiny houses constructed in New Mexico or transported into New Mexico must be inspected for compliance with New Mexico Residential Code requirements.
- A tiny house on a chassis with a permanent axle is treated as a recreational vehicle and must meet recreational-vehicle codes and licensing requirements while the axle remains in place.
- If axles are removed and the unit is placed on supports or a foundation, it must comply with the code requirements for tiny houses on a permanent foundation.
- The rule applies to construction, use, and occupancy subject to the jurisdiction of the Construction Industries Division; construction not addressed in the residential code must comply with the New Mexico Commercial Building Code.
maximum floor area excluding lofts: <= 400 square feet (The definition excludes loft area and excludes recreational vehicles.) · minimum habitable-space and hallway ceiling height: >= 6 feet 8 inches (Loft ceiling heights may be lower.) · minimum bathroom, toilet-room, and kitchen ceiling height: >= 6 feet 4 inches (None stated in the cited passage.)
“This appendix shall be applicable to tiny houses used as single dwelling units providing complete independent living facilities for one or more persons”
14.7.3 NMAC — 2021 New Mexico Residential Building Code ↗Re-checked Sep 12, 2026
Manufactured homesAllowed (with conditions)
Installation and resulting residential use and occupancy of new or pre-owned manufactured homes statewide in New Mexico, subject to the Manufactured Housing Division's permitting and inspection rules.
- An installation permit or combined installation and permanent-foundation inspection permit must be obtained before installation.
- The permit must identify the licensees performing installation work and the consumer's name and address; a map is required when the address is a post-office box or rural route.
- An unlicensed homeowner working on the homeowner's own principal residential property must perform the work personally or use division-approved licensees, execute the required acknowledgment, and assume responsibility for applicable federal, state, local, code, and inspection requirements.
- Final inspection must certify that the manufactured home meets the minimum standards for use and occupancy under the act and regulations.
- Permits are valid for 180 days, subject to possible time extension for weather or re-manufacturing or permanent-foundation inspections.
- Each new or pre-owned manufactured home installed in New Mexico requires an installation permit.
- Failure to obtain a permit subjects the homeowner, dealer, or installer to a fine of double the permit fee.
- Local requirements, codes, and inspections still apply; the cited state rule does not establish local land-use placement or zoning permission.
installation permit validity: 180 days (A time extension may be granted for weather-related delay or inspections involving a home being re-manufactured or installed on a permanent foundation.) · permit for certain alteration, modification, or repair: 15 USD (Available upon written request and excludes warranty work performed under a previous permit and installation.) · fine for installation without permit: double the permit fee (Applies to the homeowner, dealer, or installer.)
“inspectors shall certify on the permit, or upon any inspection report, that the manufactured home meets the minimum standards for use and occupancy”
14.12.9 NMAC — Inspections ↗Re-checked Sep 12, 2026
Who permits septicState (with conditions)
On-site liquid-waste and septic systems in Union County.
- Applications are submitted to the local New Mexico Environment Department field office.
- NMED reviews applications, may grant, condition, or deny permits, and conducts inspections.
- The source identifies the Office of the State Engineer for well-drilling permits, which is separate from septic permitting.
“Submit to Local NMED Field Office for review”
Apply for a Permit — New Mexico Environment Department ↗Re-checked Oct 2, 2026
3 more reviewed findings on this topic
- State (with conditions) — Onsite liquid-waste systems in Union County.
  “Bernalillo County is the only county in New Mexico that has its own onsite wastewater ordinance.”
  Liquid Waste Regulations ↗Re-checked Oct 3, 2026
- State (with conditions) — Onsite liquid-waste and septic systems in Union County.
  “Submit to Local NMED Field Office for review”
  Apply for a Permit ↗Re-checked Oct 4, 2026
- State — On-site liquid waste systems and effluent receiving 5,000 gallons or less per day and not requiring a discharge plan or NPDES permit.
  “20.7.3.1 ISSUING AGENCY: New Mexico Environmental Improvement Board.”
  20.7.3 NMAC — Liquid Waste Disposal and Treatment ↗Re-checked Sep 12, 2026
Septic permitRequired
Installation or modification of a new or existing on-site liquid waste system, including residential or commercial units on lots for which such a system is required.
- A permit issued by the New Mexico Environment Department, including payment of the permit fee, is required before construction or modification.
- A permit is not required for graywater discharges or systems meeting 20.7.3.810 NMAC.
- A dwelling may not be constructed, modified, or transported onto a lot requiring an on-site liquid waste system unless the department has issued the permit beforehand.
- Other state, city, county, or federal approvals may also be required.
- The department generally acts within 10 working days after a completed conventional-system application, subject to the rule's extension for potentially more stringent requirements.
maximum regulated flow: <= 5000 gallons per day (20.7.3.2 NMAC scope limitation) · permit application completeness determination: 5 working days (Conventional systems) · conventional permit decision: 10 working days (After receipt of a completed application; review may extend to 20 working days when more stringent requirements may be necessary)
“No person shall install or have installed a new on-site liquid waste system or modify or have modified an existing on-site liquid waste system, unless that person obtains a permit issued by the department, including payment of the permit fee, prior to construction of such installation or modification.”
20.7.3.401 NMAC — Permitting; General Requirements ↗Re-checked Sep 12, 2026
4 more reviewed findings on this topic
- Required — Installation, registration, construction, or modification of liquid-waste systems in Union County.
  “Application – Print and fill out an Application for Liquid Waste Permit, Section 20.7.3.401 NMAC [...] Submit to Local NMED Field Office for review [...] Actions may included granting the permit, granting with conditions, or denial [...] Pay for Permit only after you are contacted by NMED to inform you that your permit was approved or approved with conditions. DO NOT SUBMIT PAYMENT BEFORE NOTICE OF APPROVAL.”
  Apply for a Permit ↗Re-checked Sep 26, 2026
- Required — Installation or modification of onsite liquid-waste systems in Union County.
  “Application – Print and fill out an Application for Liquid Waste Permit, Section 20.7.3.401 NMAC”
  Apply for a Permit ↗Re-checked Oct 3, 2026
- Required — Installation, modification, registration, or operation of onsite liquid-waste systems in Union County.
  “Application – Print and fill out an Application for Liquid Waste Permit, Section 20.7.3.401 NMAC”
  Apply for a Permit ↗Re-checked Oct 4, 2026
- Required — Installation or modification of on-site liquid waste (septic) systems receiving 5,000 gallons or less per day, statewide
  “no person shall install or have installed a new on-site liquid waste system or modify or have modified an existing on-site liquid waste system, unless that person obtains a permit issued by the department, including payment of the permit fee, prior to construction of such installation or modification.”
  20.7.3 NMAC Liquid Waste Disposal and Treatment (NM State Records Center and Archives) ↗Re-checked Nov 6, 2026
Septic inspectionLimited
Property transfers involving property with an established on-site liquid waste system, subject to the applicable local exception for unincorporated Bernalillo County.
- Before transfer, the transferor must have the established on-site liquid waste system evaluated.
- The evaluation must be performed by an evaluator qualified under 20.7.3.904(B) using a department-approved form.
- Unpermitted systems must be registered under 20.7.3.401(J) or permitted under 20.7.3.401(K).
- Evaluators must submit copies of evaluation reports, whether completed or not, to the department within 15 days.
- A permit or variance application must be submitted within 15 days of the evaluation to correct deficiencies or permit violations identified by the evaluation.
- Advanced treatment systems and holding tanks have additional ownership-transfer, maintenance-contract, sampling, and permit-amendment requirements.
- An inspection or evaluation performed within the prior 180 days may support an extension request if the permitted system has not been used since that inspection or evaluation.
evaluation-report submission deadline: 15 days (Evaluators must submit copies of all reports, whether completed or not) · permit or variance application deadline after evaluation: 15 days (Applies when correcting deficiencies or permit violations identified by the evaluation) · possible evaluation extension lookback: 180 days (The system must not have been in use since the inspection or evaluation)
“Prior to the transfer of a property with an established on-site liquid waste system, the transferor of the property shall have the system evaluated. Liquid waste systems shall be evaluated by an evaluator qualified in accordance with Subsection B of 20.7.3.904 NMAC utilizing a department approved form.”
Property Transfer Evaluations ↗Re-checked Oct 5, 2026
4 more reviewed findings on this topic
- Required — Liquid-waste systems requiring NMED approval in Union County.
  “Request Inspection by NMED 48 hours (2 business days) in advance (DO NOT COVER BEFORE INSPECTION) [...] After Approved Inspection you will receive a copy of the Permit to Operate”
  Apply for a Permit ↗Re-checked Sep 26, 2026
- Required — On-site liquid-waste systems in Union County.
  “Request Inspection by NMED 48 hours (2 business days) in advance (DO NOT COVER BEFORE INSPECTION)”
  Apply for a Permit — New Mexico Environment Department ↗Re-checked Oct 2, 2026
- Required — Permitted onsite liquid-waste system installation in Union County.
  “Request Inspection by NMED 48 hours (2 business days) in advance (DO NOT COVER BEFORE INSPECTION)”
  Apply for a Permit ↗Re-checked Oct 3, 2026
- Required — Permitted onsite liquid-waste systems in Union County.
  “Request Inspection by NMED 48 hours (2 business days) in advance (DO NOT COVER BEFORE INSPECTION)”
  Apply for a Permit ↗Re-checked Oct 4, 2026
Off-grid sanitationLimited
Privies, permitted on-site liquid waste systems, and qualifying private residential graywater discharges statewide.
- A privy may dispose of human excreta and toilet paper but not other liquid wastes.
- Untreated liquid waste must go to a permitted and approved enclosed system, permitted and approved treatment unit, or public sewer, except qualifying graywater.
- Graywater under 250 gallons per day may be used for household gardening, composting, or landscaping irrigation only if all listed conditions are met, including no runoff, no spraying, no watercourse discharge, floodway exclusion, five-foot groundwater separation, local ordinance compliance, 24-hour storage limit, and specified well setbacks.
- Graywater use for purposes other than irrigation or composting requires a department permit.
private residential graywater discharge: < 250 gallons per day (Qualifying graywater discharge under 20.7.3.810 NMAC) · graywater setback from private domestic well: >= 100 feet · graywater setback from public water supply well: >= 200 feet · graywater storage before discharge: <= 24 hours
“A privy may be used for the disposal of human excreta and toilet paper, but not for the disposal of other liquid wastes.”
20.7.3 NMAC — Liquid Waste Disposal and Treatment ↗Re-checked Sep 12, 2026
Well permitRequired
Drilling a water well in New Mexico, including domestic, livestock, and other uses addressed by the Office of the State Engineer.
- A permit to drill must be obtained from the Office of the State Engineer before drilling.
- If the groundwater source is unclear, an exploratory permit may first be obtained; if that well produces water, a permit to use the water may then be obtained.
- Domestic wells are allowed by state law unless prohibited by a local ordinance. Domestic use includes household purposes, noncommercial watering of domesticated animals, and irrigation of noncommercial lawn, garden, trees, or landscaping up to one acre.
- Well-drilling permits may also be obtained for drinking and sanitary water at governmental or commercial facilities and for livestock purposes.
- An applicant drilling on land not owned by the applicant must submit written authorization with the well-permit application.
- The permits described by the Office of the State Engineer automatically expire unless the well is completed within one year of issuance; after expiration, a new application and additional filing fee are required before drilling.
- For domestic well permits under 19.27.5 NMAC, drilling and the amount and uses of permitted water remain subject to additional or more restrictive limitations imposed by a court or lawful municipal or county ordinance.
domestic noncommercial irrigation limit: <= 1 acre (Applies to noncommercial lawn, garden, trees, or landscaping included in domestic use.) · permit completion deadline: <= 1 year from permit issuance (The permit automatically expires if the well is not completed within this period.)
“Before you have a well drilled, you must first obtain a permit to drill from the Office of the State Engineer.”
Drilling Your Water Well ↗Re-checked Nov 4, 2026
One more reviewed finding on this topic
- Required — Use of water (including from wells) in New Mexico; permits obtained through the local Office of the State Engineer water rights district office
  “anyone wanting to use water in new mexico must have a permit from the state engineer that can be obtained by contacting your local district office.”
  New Mexico Office of the State Engineer home page ↗Re-checked Nov 6, 2026
Mandatory utility hookupWater and sewer (with conditions)
Connection or reconnection of a plumbing system to a water source or sewer system in buildings or systems regulated by New Mexico construction codes, including Union County.
- Approval by the appropriate authority having jurisdiction or inspector is required before connection or reconnection.
- A public or private utility may connect a supply of water or gas if the appropriate AHJ has failed to approve or disapprove the work within seven working days after receiving notification that the work is ready for inspection.
- The seven-working-day exception expressly applies to a supply of water or gas; the cited rule does not extend that exception to sewer connections.
- The rule governs plumbing systems and does not establish that every utility service in every circumstance is administered by Union County.
AHJ response period for water-connection exception: 7 working days (The AHJ must have failed to approve or disapprove after receiving notification that the work is ready to inspect)
“Plumbing. No person shall connect, or reconnect, any plumbing system to an energy or water source or to a sewer system until the AHJ or appropriate inspector has given approval to do so.”
14.5.3 NMAC Inspections ↗Re-checked Oct 4, 2026
One more reviewed finding on this topic
- Conditional — Residential and commercial units using an on-site liquid waste system when a public sewer is available and connection is required by the local authority with jurisdiction.
  “All residential and commercial units utilizing an on-site liquid waste system shall connect to a public sewer upon availability and if required in accordance with the local authority that has jurisdiction.”
  20.7.3 NMAC — Liquid Waste Disposal and Treatment ↗Re-checked Sep 12, 2026
Agricultural exemptionConditional
Statewide agricultural exemption from the New Mexico Subdivision Act for the sale, lease, or other conveyance of a parcel of at least 35 acres.
- The parcel must be thirty-five acres or larger.
- The conveyance must occur within a twelve-month period covered by the statutory exception.
- The land must have been used primarily and continuously for agricultural purposes, in accordance with Section 7-36-20 NMSA 1978, for the preceding three years.
minimum parcel size: >= 35 acres · agricultural use duration: >= 3 years (land must have been used primarily and continuously for agricultural purposes in accordance with Section 7-36-20 NMSA 1978) · conveyance period: 12 months (within any twelve-month period)
“the sale, lease or other conveyance of any parcel that is thirty-five acres or larger in size within any twelve-month period; provided that the land has been used primarily and continuously for agricultural purposes, in accordance with Section 7-36-20 NMSA 1978, for the preceding three years;”
Senate Bill 176 — New Mexico Subdivision Act ↗Re-checked Sep 12, 2026
2 more reviewed findings on this topic
- Conditional — New Mexico contractor licensing requirements for earthmoving, excavating, and ditching activities used in preparation or production of agriculture or maintenance of livestock on a farm or ranch.
  “earthmoving, excavating and ditching activities applicable to the preparation and production of agriculture or maintenance of livestock on a farm or ranch are exempt from licensing requirements.”
  srca.nm.gov ↗Re-checked Oct 1, 2026
- Conditional — Agricultural land divisions and conveyances that would otherwise fall within the New Mexico Subdivision Act definition.
  “provided that the land has been used primarily and continuously for agricultural purposes, in accordance with Section 7-36-20 NMSA 1978”
  Senate Bill 176 — New Mexico Subdivision Act amendments ↗Re-checked Oct 5, 2026
Shed and accessory-building permit exemptionAvailable
One-story detached accessory structures for residential construction subject to Construction Industries Division jurisdiction.
- The exemption is limited to a one-story detached accessory structure with floor area not exceeding 120 square feet.
- The exemption concerns the building permit requirement; unless otherwise exempted, separate plumbing, electrical, and mechanical permits may still be required.
- The applicable 14.5.2 NMAC amendment to the permit-exception provision is effective July 14, 2023.
maximum floor area: <= 120 square feet (One-story detached accessory structures under the residential exception.)
“One-story detached accessory structures provided that the floor area does not exceed 120 square feet (18.58 m2).”
New Mexico Register, Volume XXXIV, Issue 11 — 14.5.2 NMAC permit exceptions ↗Re-checked Nov 4, 2026
Driveway accessRequired
Permanent or temporary direct vehicular access from property in close proximity to or adjoining a New Mexico state highway.
- An access permit must be issued by the New Mexico Department of Transportation before constructing or modifying covered access.
- Access permits are issued only when the application complies with 18.31.6 NMAC.
- The department or an approved issuing authority may impose terms and conditions.
- The rule concerns state highways under the jurisdiction of the state transportation commission; it does not establish a universal permit requirement for every non-state roadway.
- For additional traffic from expansion or redevelopment, the property owner must contact the department to determine whether a new application or access modification is required; no new application is required if the department determines modifications are unnecessary.
“no person shall construct or modify any permanent or temporary access [...] without an access permit issued by the New Mexico department of transportation.”
18.31.6 NMAC ↗Re-checked Sep 12, 2026
Building in a floodplainRequired
Construction or development within a FEMA Special Flood Hazard Area in a New Mexico community, and proposed construction or other development in communities where FEMA has not defined a Special Flood Hazard Area.
- Approval by the local community Floodplain Administrator is required before construction or development within any Special Flood Hazard Area.
- Where FEMA has not defined the Special Flood Hazard Area, the community must require permits for all proposed construction or other development, including manufactured homes, to determine whether the activity is in a flood-prone area.
- Approval is intended to ensure compliance with the National Flood Insurance Program and the community’s floodplain management ordinance.
- The source identifies 104 New Mexico communities participating in the National Flood Insurance Program; the administering official is the applicable local community Floodplain Administrator, not the state agency.
“Approval by the local community Floodplain Administrator is required before construction or development begins within any Special Flood Hazard Area.”
Flooding ↗Re-checked Sep 12, 2026
Permit feesPublished (with conditions)
New Mexico liquid-waste permits applicable in Union County.
- The fee table states an effective date of 07/01/2020.
- Examples include $225 for a conventional system up to 1,000 gallons per day, $325 for 1,001–2,000 gallons per day, and $500 for 2,001–5,000 gallons per day.
- The page also lists inspection, variance, homeowner qualification, and advanced-treatment fees.
conventional liquid-waste system up to 1000 gpd: 225 USD (fee table effective 07/01/2020)
“Conventional system, register, construct, or modify design flow up to 1,000 gpd | 7/1/20 | $225.00”
Apply for a Permit — Permit Fees ↗Re-checked Oct 4, 2026
3 more reviewed findings on this topic
- Published (with conditions) — New Mexico CID building-permit fees applicable to construction in Union County.
  “Permitting Fees are based upon type of construction, square footage, type of materials and construction costs.”
  Construction Industries Forms and Applications Fees ↗Re-checked Sep 26, 2026
- Variable (with conditions) — CID homeowner building-permit applications in New Mexico, including Union County.
  “Submit the building permit fee, which CID will provide as soon as you let us know what the total cost of the project is going to be.”
  Construction Industry | Frequently Asked Questions | NM RLD ↗Re-checked Oct 3, 2026
- Variable (with conditions) — New Mexico Construction Industries Division permitting fees for covered construction work statewide.
  “Permitting Fees are based upon type of construction, square footage, type of materials and construction costs.”
  Construction Industries Forms and Applications Fees ↗Re-checked Sep 12, 2026
Permit processPublished (with conditions)
CID residential building-permit process applicable to construction in Union County.
- Homeowner applications require planning and zoning approval when applicable, two complete sets of plans, the Multi-Purpose State Building Application, and payment of the building permit fee.
- CID states that complete packages are reviewed and a building permit issued within five working days; residential permits are generally processed in three to four working days.
- Zoning approval, incomplete information, or missing professional stamps may delay processing.
complete-package issuance target: 5 working days · residential processing time: 3 to 4 working days
“issue a building permit within five (5) working days”
Construction Industries Division Frequently Asked Questions ↗Re-checked Sep 26, 2026
4 more reviewed findings on this topic
- Published (with conditions) — CID-regulated construction permit process in Union County.
  “In order to obtain a permit, the applicant must complete and submit an application on an AHJ approved form for the type of permit sought.”
  14.5.2 NMAC — Permits ↗Re-checked Oct 2, 2026
- Published (with conditions) — CID homeowner building-permit applications in New Mexico, including Union County.
  “issue a building permit within five (5) working days.”
  Construction Industry | Frequently Asked Questions | NM RLD ↗Re-checked Oct 3, 2026
- Published (with conditions) — State building and liquid-waste permit processes applicable in Union County.
  “Residential permits are being processed in 3 to 4 working days. Commercial permits are processed in 5 to 10 working days.”
  Building Permit Guide for Residential Construction ↗Re-checked Oct 4, 2026
- Published (with conditions) — Construction Industries Division permit applications in New Mexico.
  “Permits can also be completed using our online permitting portal.”
  Forms and Applications ↗Re-checked Sep 12, 2026
Campground & park staysLimited
A tiny house constructed on a chassis with a permanent axle in New Mexico.
- The unit is considered a recreational vehicle and must meet recreational-vehicle codes and be licensed as a recreational vehicle while the axle remains in place.
- This is a statewide construction and classification rule for chassis-mounted tiny houses; it does not establish a general statewide authorization for long-term RV occupancy on private land.
- Local planning and zoning approval may independently apply to a project.
permanent axle condition: The recreational-vehicle classification applies so long as the axle remains in place.
“Tiny houses constructed on a chassis with permanent axle shall be considered recreational vehicles and shall meet codes for and be licensed as recreational vehicles so long as the axle remains in place.”
14.7.3 NMAC — 2021 New Mexico Residential Building Code ↗Re-checked Nov 4, 2026
county zoning authorityGeneral
New Mexico counties adopting zoning for all or part of unincorporated territory outside municipal zoning jurisdiction.
- A county zoning ordinance may apply only to territory not within the zoning jurisdiction of a municipality.
- Municipalities may have concurrent extraterritorial zoning authority in specified areas, including areas near municipalities meeting statutory population thresholds and additional contiguous territory placed under municipal extraterritorial jurisdiction by county-municipal agreement.
- Concurrent extraterritorial authority is exercised under an extraterritorial zoning authority or joint powers agreement and may be exercised regardless of whether the county has enacted a comprehensive zoning ordinance.
- If no county zoning ordinance exists, qualified electors may petition for adoption; the petition must equal at least twenty-five percent of the votes cast for governor at the last preceding general election, and the board of county commissioners must adopt a county zoning ordinance within one year.
minimum petition threshold: >= 25 percent of votes cast for governor at the last preceding general election · county ordinance adoption deadline after qualifying petition: 1 year
“a county zoning authority may adopt a zoning ordinance applicable to all or any portion of the territory within the county that is not within the zoning jurisdiction of a municipality;”
nmlegis.gov ↗Re-checked Oct 5, 2026
One more reviewed finding on this topic
- General — New Mexico counties may adopt zoning ordinances for all or any portion of county territory that is not within a municipality's zoning jurisdiction.
  “A. a county zoning authority may adopt a zoning ordinance applicable to all or any portion of the territory within the county that is not within the zoning jurisdiction of a municipality;”
  nmlegis.gov ↗Re-checked Sep 21, 2026
county building authorityGeneral
New Mexico counties that establish and maintain a building department for permitting and inspections of general construction, mechanical-plumbing, and electrical work, including residential construction in unincorporated areas.
- CID retains statewide permitting and inspection authority unless a county, municipality, or political subdivision has a current building department providing permitting and inspections.
- To establish and maintain a building department, the county must establish a full-service building department covering general construction, mechanical-plumbing, and electrical trades; employ a full-time certified building official; and employ sufficient CID-certified inspectors for each trade.
- The county authority does not include liquefied petroleum work, over which CID has exclusive authority.
- CID conducts all inspections if the county lacks a certified building official.
- If the certified building official leaves, plan review, permitting, and inspections transfer to the state unless the county replaces the official within 60 days or a longer period approved by the division, or enters a memorandum of understanding with another county, municipality, or political subdivision.
replacement period for certified building official: 60 days (A longer period may be approved by the division.)
“In order to establish and maintain a building department allowing permitting and inspections the county, municipality or political subdivision must establish a full-service building department including general construction, mechanical-plumbing and electrical trades, must employ a full-time certified building official and employ sufficient CID certified inspectors to inspect for each trade.”
14.6.5 NMAC — Inspectors and Building Officials ↗Re-checked Oct 5, 2026
One more reviewed finding on this topic
- Limited — New Mexico counties that qualify as an authority having jurisdiction may administer permitting, inspection, and enforcement for residential construction in unincorporated areas and enforce applicable New Mexico construction codes.
  ““Authority having jurisdiction” “AHJ” means the state or a municipality, county or other political subdivision that has a full-service building department employing a full-time certified building official and has permitting, inspection and enforcement authority over the general construction, electrical and mechanical-plumbing trades within its jurisdiction.”
  14.5.1 NMAC, Construction Industries General Provisions ↗Re-checked Sep 21, 2026

Still unanswered

We looked and could not find an official answer yet. Silence is not permission — ask the county directly.

County-wide zoning — Countywide zoning administration in Union County, including unincorporated areas.
Local zoning — Aggregate local zoning status across Union County and any incorporated municipalities.
Zoning districts — Published county zoning districts in Union County.
Minimum lot size — Minimum lot size in Union County, New Mexico, including unincorporated areas.
Setbacks — Building setbacks in Union County, New Mexico, including unincorporated areas.

5 more unanswered

Lot coverage
Living in an RV
Camping on your land
Accessory dwellings
Short-term rentals

Each answer was extracted from an official source and independently re-checked against that source by a second reviewer. That is an evidence check, not legal advice. Rules change; confirm with the authority before you buy or build.

Water rights & wells in Union County

Whether a new home can legally get its own water here — the sub-state groundwater regime, from New Mexico’s water agency.

Actively managed

This basin is under active state management — new water use is scrutinized, though a domestic well is usually still allowed.

Household wellPermit required (issued by right)

Nearly all developed New Mexico lies inside an OSE 'declared' underground water basin, but a household 72-12-1.1 domestic well is a by-right permit the State Engineer issues even in closed/over-appropriated basins (metering can be required). The by-right amount is cut to 0.25 acre-ft/yr in a declared Domestic Well Management Area, and a few basin-specific orders cap it further (Gallup Order 197, Zuni Order 199) or stop issuing new domestic permits entirely (Hot Springs Order 198).

Limit: 1 acre-ft/yr by right (NMSA 72-12-1.1); 0.25 acre-ft/yr in a declared Domestic Well Management Area

NM OSE domestic well rules, 19.27.5 NMAC ↗

Tucumcari Underground Water Basinpartial of county
OSE-declared Article-7 groundwater basin; new non-domestic (72-12-3) appropriations require an OSE permit showing unappropriated water. The 72-12-1.1 household domestic well remains by-right — no Domestic Well Management Area is declared in New Mexico. OSE-declared basin centered on Quay County (Order 155, 1998).
NM OSE Article 7 (Declared Underground Water Basins) ↗
Clayton Underground Water Basin (Eastern portion)partial of county
OSE-declared Article-7 groundwater basin; new non-domestic (72-12-3) appropriations require an OSE permit showing unappropriated water. The 72-12-1.1 household domestic well remains by-right — no Domestic Well Management Area is declared in New Mexico. OSE 2019 guidelines apply block administration to the thin (<50 ft) Ogallala/High Plains aquifer; guidelines expressly exempt 72-12-1.1 domestic wells.
NM OSE Eastern Clayton Basin Guidelines (2019) ↗

Prior-appropriation state (first in time, first in right). Groundwater rules change and basin boundaries follow the aquifer, not the county line — confirm current well and appropriation rules with the New Mexico state water agency before you buy or drill.Groundwater governance as of Jul 2026, cited to each administering agency.

Living off-grid in Union County, New Mexico

Is Union County a good place to live off-grid or homestead?

Union County scores 35/100 on the Bolthole Index, a marginal county profile. Its strengths: deep seclusion — about 50 people within a 30-minute drive and manageable long-term carry cost. Watch-outs: thin water margin (16.2″/yr rainfall) and elevated current hazard exposure.

How much does land cost in Union County, New Mexico?

Land in Union County runs about $852 per acre, based on the latest county data.

What is the water situation in Union County?

Union County gets about 16.2" of rain a year, with severe drought in roughly 46.8% of years. On water rights, Union County lies in the Tucumcari Underground Water Basin — OSE-declared Article-7 groundwater basin; new non-domestic (72-12-3) appropriations require an OSE permit showing unappropriated water. The 72-12-1.1 household domestic well remains by-right — no Domestic Well Management Area is declared in New Mexico. OSE-declared basin centered on Quay County (Order 155, 1998)..

How remote is Union County?

A representative private-land location has about 50 people within a 30-minute drive and 27,826 within two hours. The road-network catchments count population across county lines and clusters of smaller cities; straight-line radius values remain available as a comparison.

Building permits, zoning and land rules in Union County, New Mexico