Bolthole Index

Los Alamos County, New Mexico

Building permits, zoning and land rules in Los Alamos County, New Mexico

42Index Score / 100
#15 of 33 in New Mexico

Los Alamos County, New Mexico requires building permits for covered residential construction and alterations; starting before issuance can bring double fees and removal of work for inspection.1 County Planning administers zoning, with allowed uses and dimensional standards tied to the parcel’s district.23 Septic permits come from the New Mexico Environment Department before new systems are installed or existing systems are modified, except qualifying graywater systems.45

At a glance

Building permit
Required for covered residential construction and alterations6
Inspections
Required, including a final inspection for covered construction7
Zoning
Countywide; parcel rules vary by zone district28
Septic permit
State permit required before covered installation or modification910
Tiny home
Permanent-foundation units must meet state code and county zoning1112
RV living
Private-land residential occupancy was not confirmed; ask County Planning12
Accessory dwelling unit
250–800 square feet, no larger than the primary dwelling; district restrictions apply1314

Who to call

Building permits

Los Alamos County Community Development Department, Building Safety Division

Residential building permit applications, plan review and inspections for Los Alamos County

505-662-8120

permit.techs@lacnm.us

1000 Central Avenue, Suite 150 Los Alamos, NM 87544

Zoning

Los Alamos County Community Development Department, Planning Division

Zoning, district maps and land-use questions for Los Alamos County

505-662-8120

cdd@losalamosnm.gov

1000 Central Avenue, Suite 150 Los Alamos, NM 87544

Septic permits

New Mexico Environment Department Santa Fe District Office

Liquid-waste permit questions and permit searches for the Santa Fe district

505-827-1840

santafe.ehb@env.nm.gov

2540 Camino Edward Ortiz, Santa Fe, NM 87507

Contact details are copied from each office’s official page and were checked against it on October 10, 2026.

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

Los Alamos County requires building permits for covered residential construction and alterations, and work must wait until the permit is issued.1 Starting early can bring double fees and require removal of work for inspection.15 Submitted plans must meet applicable County regulations and adopted codes, including the 2021 building, residential, energy and fire codes; not every code applies to every project.1617

Work must remain accessible and exposed until approved, and cannot proceed beyond a required inspection point without written approval.18 Covered construction requires a final inspection for a Certificate of Completion or Certificate of Occupancy, depending on the project.1920 Final state electrical and mechanical inspections must precede the County final inspection.20

Who handles Los Alamos County building permits, and how do you apply?

The Los Alamos County Building Safety Division administers residential building permits; call 505-662-8120, email permit.techs@lacnm.us or visit 1000 Central Avenue, Suite 150, Los Alamos.2122 The Planning Division, at the same address and phone number, answers zoning and district questions.23 Start with the project checklist, prepare the required plans, review the published fees, and submit the application online or in person.24 The County requires 2 sets of building plans and site plans for plan review, and says most residential permits take 3 business days to process.22

After staff review, the County contacts the applicant if more information is needed; once the application is approved, the permit technician collects the remaining fees and issues the permit.22 Electrical, plumbing and mechanical inspections are performed by the New Mexico Construction Industries Division rather than the County.7 Keep the work exposed at each required inspection point and arrange the applicable final inspections before requesting the County's final approval.7

Does Los Alamos County have zoning?

Los Alamos County Planning administers countywide zoning under Chapter 16 of the Development Code.2 County Planning can identify a parcel’s zoning district and allowable uses; published Townsite and White Rock maps and the parcel map help locate the property.2526 Minimum lot size, setbacks, height and density depend on the district, so ask Planning for the applicable district standards before designing a home.272829

Accessory dwelling units are permitted in SFR-1, SFR-2, SFR-3, RA, RE, RM and MFR-L, subject to use-specific standards.14 Los Alamos County ADUs must contain 250–800 square feet and cannot exceed the primary dwelling’s gross floor area.13 A building permit is required before ADU construction, and base-zone lot, setback, coverage and height standards still apply.13 Subdivision plats receive Planning and Zoning Commission review, while qualifying summary plats may be handled administratively.30

How do septic permits work in Los Alamos County?

The New Mexico Environment Department administers septic permits in Los Alamos County.4 New or modified onsite liquid-waste systems require a paid state permit before construction, except graywater systems meeting the state exemption; other local approvals may also apply.5 The Santa Fe District Office handles liquid-waste permit questions and permit searches.31

A homeowner installing a conventional system must pass the NMED qualification exam and may install it only for the homeowner’s personal residence, not a rental or another property.32 Homeowner installations require a final NMED inspection before covering the system, and the permit may require additional inspections.33 Before transfer of a property with an established onsite system, the system must be evaluated and the evaluation report submitted to NMED within 15 days.34

Only about 2.5% of mapped county soils avoid severe conventional drain-field limitations, making a parcel-specific site evaluation important before buying.35 Where public sewer is available and the local authority requires connection, onsite-system users must connect and properly abandon the old system within 30 days afterward.36 Cesspools are prohibited, and untreated waste disposal must follow state sanitation rules.37

Can you live in an RV or tiny home in Los Alamos County?

A permanent-foundation tiny house can qualify as a dwelling under New Mexico’s residential code if it provides complete living facilities and meets state tiny-house requirements.11 Los Alamos County zoning still controls residential use and district standards.3 If the tiny home is an accessory dwelling unit, the County’s 250–800-square-foot range applies, and the unit cannot exceed the primary dwelling’s gross floor area.13 That ADU rule does not establish a minimum floor area for every principal dwelling.13

A tiny house on a chassis with a permanent axle is treated as an RV under the state rule.11 Los Alamos County prohibits camping, including RV occupancy, on county-owned or county-leased property except designated campgrounds.38 We could not confirm permission for long-term RV occupancy or temporary camping on private land; ask County Planning about the parcel, duration and sanitation before relying on that arrangement.23 Manufactured-home placement requires a County application packet and compliance with district standards.39

Building a home in Los Alamos County: what are the steps?

  1. Find the parcel on the County map, identify its district, and confirm that the dwelling and any accessory unit are allowed.2640
  2. Use the district standards to shape the site plan, including the applicable setbacks and height limit.4142
  3. If the site needs onsite wastewater, obtain state approval before installing or modifying the system.10
  4. Complete the project checklist and submit the residential application and plans before starting work.24
  5. Pay the plan-review fee when submitting plans and remaining permit fees after approval.4322
  6. Schedule County and state trade inspections as applicable, leaving work exposed until approval.7
  7. Pass the final inspection and obtain the applicable Certificate of Completion or Certificate of Occupancy.20

What should you check before buying land in Los Alamos County?

Before buying in Los Alamos County, confirm the parcel’s district, allowed residential use, minimum lot size, setbacks and height standards with County Planning.25274142 For an existing septic system, ask the Santa Fe District Office for the permit record and arrange the required pre-transfer evaluation.3134

Identify the road authority: constructing or modifying access to a state highway requires a New Mexico Department of Transportation permit.44 Ask the local Floodplain Administrator about special flood hazard areas, where approval is required before covered development.45

Budget separately for planning fees based on project type, building permit fees based on construction value, and applicable water, sewer and electric connection fees.46 The County’s plan-review fee is 65% of the building permit fee and is due with the plans; revisions can add hourly charges.43

Watch-outs

  • Starting covered construction before Los Alamos County issues the permit can trigger double fees and removal of work for inspection.6
  • Standard inspections are included in the permit fee, but reinspections and inspections outside normal business hours can cost extra.47
  • A property's zone district—not the listing description—controls its allowed uses and dimensional standards.12

Sources

  1. Apply for a Residential Building Permit, quoted and re-checked
  2. Planning Division, quoted and re-checked
  3. Development Information for Los Alamos County, quoted and re-checked
  4. Onsite Wastewater Program, quoted and re-checked
  5. 20.7.3 NMAC, quoted and re-checked
  6. Apply for a Residential Building Permit, quoted and re-checked
  7. Inspections, quoted and re-checked
  8. Planning Division, quoted and re-checked
  9. Environmental Health Bureau, quoted and re-checked
  10. Homeowners Information, quoted and re-checked
  11. 14.7.3 NMAC — 2021 New Mexico Residential Building Code (New Mexico statewide rule), quoted and re-checked
  12. Planning Division, quoted and re-checked
  13. Los Alamos County Code § 16-18, Accessory uses, quoted and re-checked
  14. losalamosnm.gov, quoted and re-checked
  15. Apply for a Residential Building Permit, quoted and re-checked
  16. Building Code & Policy Information, quoted and re-checked
  17. Building Code & Policy Information, quoted and re-checked
  18. Inspections, quoted and re-checked
  19. losalamosnm.gov, quoted and re-checked
  20. Inspections, quoted and re-checked
  21. Los Alamos County Community Development Department, Building Safety Division (losalamosnm.gov)
  22. Apply for a Residential Building Permit, quoted and re-checked
  23. Los Alamos County Community Development Department, Planning Division (losalamosnm.gov)
  24. Apply for a Residential Building Permit, quoted and re-checked
  25. Development Information for Los Alamos County, quoted and re-checked
  26. Planning Division, quoted and re-checked
  27. Planning Division FAQs, quoted and re-checked
  28. Planning Division FAQs, quoted and re-checked
  29. Planning Division FAQs, quoted and re-checked
  30. Development Information for Los Alamos County, quoted and re-checked
  31. New Mexico Environment Department Santa Fe District Office (env.nm.gov)
  32. Homeowners Information, quoted and re-checked
  33. Homeowners Information, quoted and re-checked
  34. Homeowners Information, quoted and re-checked
  35. Share of soils USDA rates "not limited" for a conventional septic drain field (SSURGO). A strict rating: the median county is about 6% and a tenth of counties are 0%, so a low figure means most lots need a site evaluation or an engineered system, not that septic is impossible. Cite it only with that caveat: Bolthole Index county data
  36. srca.nm.gov, quoted and re-checked
  37. 20.7.3 NMAC, quoted and re-checked
  38. Los Alamos County Code § 38-752, Unlawful camping, quoted and re-checked
  39. Administrative Applications, quoted and re-checked
  40. Planning Division FAQs, quoted and re-checked
  41. Planning Division FAQs, quoted and re-checked
  42. Planning Division FAQs, quoted and re-checked
  43. Building Permit Fees, quoted and re-checked
  44. 18.31.6 NMAC (New Mexico statewide rule), quoted and re-checked
  45. Flooding (New Mexico statewide rule), quoted and re-checked
  46. Development Information for Los Alamos County, quoted and re-checked
  47. Apply for a Residential Building Permit, quoted and re-checked

Written October 10, 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.

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Compared with neighboring counties

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

RuleLos Alamos CountySanta Fe CountySandoval CountyRio Arriba CountyBernalillo CountyTaos CountyMora County
Building permitRequiredRequiredRequiredRequiredRequiredRequiredRequired
County zoningYesYesYesYesYesYesYes
Septic permitsNM Env. Dept.NM Env. Dept.NM Env. Dept.NM Env. Dept.County Public WorksNM Env. Dept.NM Env. Dept.

County locator

Los Alamos County in New Mexico

42
County map
Los Alamos County highlighted among the New Mexico counties · colored by Index score

How Los Alamos County scores

Seclusion5946% ev.
Self-Sufficiency20100% ev.
Admin Boringness44100% ev.
Durability59100% ev.
Property Autonomy38100% ev.
Carry Cost3496% ev.

Evidence strength: 88%. This reports direct-source completeness and fallback use; it is separate from the score and is not a confidence interval. How it works →

$594kTypical home
0.6%Property tax
$24,134Land / acre
18"Annual rain
37.1% of yrsSevere drought
0.9 / yr (+0.9)Mid-century 100°F days
28.1 daysMid-century dry spell
1.19" (+-0.6%)Mid-century 1-day rain
1.32×Wildfire change factor
100%Forward climate coverage
$1,488Home insurance / yr
2.7% / yrInsurance growth
0.29%Nonrenewal rate
single ZIP shrunk to state medianInsurance basis
24,658People within 30 min
1,282,252People within 2 hr
27,887Radius comparison (15 mi)
178.2People / sq mi
85.3%Federal land
34.9%Land at 15% slope or less
2.5%Soils rated "not limited" for septic (strict USDA rating)
1,609 acWorkable land screen
55.4%Wooded land
2.2 tonsBiomass / forest ac
47.6°FAvg temp

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Answers from the rulebook for Los Alamos County

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

Los Alamos County rules

  • Building permitRequired

    Residential construction, alteration, and construction projects on a home in Los Alamos County.

    • Construction must not begin before the permit is obtained.
    • Starting before obtaining a permit can result in double fees and removal of work for inspection.
    “Please note that you should not start construction before obtaining your permit. If you do, you will incur double fees and risk delays by being required to remove some of your work for inspection purposes.”
    2 more reviewed findings on this topic
    • Required — Residential construction and alteration projects requiring County permits.
      “Please note that you should not start construction before obtaining your permit. If you do, you will incur double fees and risk delays by being required to remove some of your work for inspection purposes.”
    • Required — Residential construction projects in Los Alamos County.
      “Please note that you should not start construction before obtaining your permit.”
  • Building code adoptedAdopted (with conditions)

    Building projects subject to Los Alamos County building regulation.

    • Not every listed code or portion of a code necessarily applies to every project.
    • The county lists the 2021 International Building Code, 2021 International Residential Code as amended by New Mexico, 2021 International Energy Conservation Code, and 2021 International Fire Code.
    “All submitted plans must conform to the following codes and ordinances.”
    One more reviewed finding on this topic
    • Adopted (with conditions) — Building projects governed by Los Alamos County building regulations.
      “All submitted plans must conform to the following codes and ordinances.”
  • InspectionsRequired

    Construction requiring County building inspections.

    • Work must remain accessible and exposed until approved.
    • The permit holder or agent must notify Building Safety when work is ready.
    • Work may not proceed beyond a required inspection point until approved in writing.
    • Electrical, plumbing, and mechanical inspections are performed by New Mexico CID rather than the County.
    “Work shall not be done beyond the point of required inspection until the work is approved in writing by the Building Safety Division.”
    One more reviewed finding on this topic
    • Required — Construction subject to County building permits and inspections.
      “Finally, please be aware that all construction must obtain a final inspection for either a Certificate of Completion or a Certificate of Occupancy.”
  • Certificate of occupancyLimited

    Construction projects for which the County issues a Certificate of Occupancy rather than a Certificate of Completion.

    • All construction must obtain a final inspection for either a Certificate of Completion or a Certificate of Occupancy.
    • Final New Mexico electrical and mechanical inspections must be completed before the County final inspection.
    • The source does not establish that every project receives a Certificate of Occupancy.
    “Finally, please be aware that all construction must obtain a final inspection for either a Certificate of Completion or a Certificate of Occupancy.”
    2 more reviewed findings on this topic
    • Limited — Projects receiving a County final inspection and requiring an occupancy certificate.
      “If you pass your inspection, you will receive a Certificate of Occupancy.”
    • Limited — Construction projects for which the final approval document is a Certificate of Occupancy rather than a Certificate of Completion.
      “Finally, please be aware that all construction must obtain a final inspection for either a Certificate of Completion or a Certificate of Occupancy.”
  • County-wide zoningPresent

    Los Alamos County land-use regulation through County Development Code Chapter 16.

    • Chapter 16 is administered by the County Planning Division.
    • Specific requirements vary by zone district and parcel.
    “The Planning Division serves in an advisory role to appointed and elected officials in providing professional review, analysis, and recommendations regarding land use-related matters, administers Chapter 16 of the Los Alamos County Development Code”
    One more reviewed finding on this topic
    • Present (with conditions) — Land-use zoning and development regulation administered under the Los Alamos County Development Code.
      “Start by calling the Planning Division to identify: Zoning Districts and Allowable Uses”
  • Local zoningPresent (with conditions)

    Los Alamos County local zoning and land-use regulation.

    • The county's Development Code provides the local zoning framework; district-specific standards apply.
    “An application for relatively minor modification from the dimensional or numeric standards of the Development Code. (i.e. Lot Area, Lot Coverage, Height, and Setbacks).”
    2 more reviewed findings on this topic
    • Present — County-administered zoning and land-use regulation within Los Alamos County.
      “The Planning Division coordinates with internal and external partners to ensure efficient use of the land in the County”
    • Present — Los Alamos County local zoning and land-use regulation under the County Development Code.
      “The Planning Division serves in an advisory role to appointed and elected officials in providing professional review, analysis, and recommendations regarding land use-related matters, administers Chapter 16 of the Los Alamos County Development Code, processes various land use and development applications, and provides policy and regulatory basis including technical assistance to the community on current planning issues.”
  • Zoning districtsPublished

    Published Los Alamos County zoning districts and zoning maps.

    • The County Planning Division publishes Townsite and White Rock zone maps and links to Chapter 16 Development Code.
    • Parcel-specific zoning must be determined using the County parcel map.
    “Zoning Districts: Townsite Zone Map (PDF, 9MB) White Rock Zone Map (PDF, 4MB)”
    2 more reviewed findings on this topic
    • Published (with conditions) — Published Los Alamos County zoning districts and allowable uses.
      “Start by calling the Planning Division to identify: Zoning Districts and Allowable Uses”
    • Published — Los Alamos County zoning maps and Chapter 16 Development Code materials.
      “Zoning Districts: Townsite Zone Map White Rock Zone Map Los Alamos County Municipal Code Chapter 16 - View Development Code.”
  • Minimum dwelling sizeSpecified

    Accessory dwelling units in Los Alamos County; this does not establish a minimum floor area for every principal dwelling type.

    • Construction of any accessory dwelling unit requires a building permit before construction begins.
    • No more than one attached or detached accessory dwelling unit is permitted per lot.
    • Underlying base-zone lot, setback, coverage, and height standards apply.
    • A detached accessory dwelling unit must be at least ten feet from the primary dwelling.
    • One dedicated off-street parking space is required.
    • An accessory dwelling unit may not be subdivided from or separately sold from the primary dwelling unless it meets the requirements for a primary dwelling and separate lot.
    • No variance or administrative deviation may be granted for these standards.

    minimum accessory dwelling unit floor area: >= 250 square feet · maximum accessory dwelling unit floor area: <= 800 square feet (The accessory dwelling unit square footage shall not exceed the gross floor area of the primary dwelling.)

    “The square footage of the accessory dwelling unit shall not be less than 250 square feet or more than 800 square feet.”
  • Minimum lot sizeDistrict specific (with conditions)

    Minimum lot-size standards by County zone district.

    • The applicable standard depends on the zone district.
    “Dimensional standards for each zone district can be found in Chapter 16, Development Code, Article II, Division 2. Base Zone Districts. It includes lot standards, setbacks, heights, and density.”
  • SetbacksSpecified

    Development in Los Alamos County zone districts.

    • Setbacks are zone-district-specific.
    • The County directs users to Chapter 16, Article II, Division 2 and the parcel map for parcel-specific standards.
    “Dimensional standards for each zone district can be found in Chapter 16, Development Code, Article II, Division 2. Base Zone Districts.”
    One more reviewed finding on this topic
    • District specific (with conditions) — Setbacks by County zone district.
      “Dimensional standards for each zone district can be found in Chapter 16, Development Code, Article II, Division 2. Base Zone Districts. It includes lot standards, setbacks, heights, and density.”
  • Building heightSpecified

    Development in Los Alamos County zone districts.

    • Height standards are zone-district-specific.
    • The County directs users to Chapter 16, Article II, Division 2 for the applicable standards.
    “It includes lot standards, setbacks, heights, and density.”
    One more reviewed finding on this topic
    • District specific (with conditions) — Building-height standards by County zone district.
      “Dimensional standards for each zone district can be found in Chapter 16, Development Code, Article II, Division 2. Base Zone Districts. It includes lot standards, setbacks, heights, and density.”
  • Living in an RVProhibited

    Camping or occupancy of a camping vehicle, including an RV, on county-owned or county-leased property outside property specifically designated as a campground.

    • The prohibition does not apply to property specifically designated as a campground.
    • Separate county camping permits may be required at designated camping areas.
    “It is unlawful for any person to camp on any county-owned or county-leased property except property designated specifically as a campground.”
  • Manufactured homesLimited

    Placement of manufactured homes in Los Alamos County.

    • A Manufactured Home Application Packet is required before placement.
    • Placement must comply with zone-district development and dimensional standards.
    • Additional state permits may be required.
    • The county definition excludes RVs and modular or pre-manufactured homes built to Uniform Building Code standards and designed to be permanently affixed to real property.
    “Manufactured Home Application Packet: Required before placement to ensure compliance with zone district development and dimensional standards.”
  • Accessory dwellingsLimited

    Accessory dwelling units in Los Alamos County residential zone districts.

    • ADUs are permitted only in SFR-1, SFR-2, SFR-3, RA, RE, RM, and MFR-L zone districts.
    • The County states that the Chapter 16 use-specific ADU standards apply.
    • The County's FAQ directs users to the parcel map to determine the zone district.
    “ADUs are permitted in some residential zone districts: SFR-1, SFR-2, SFR-3, RA, RE, RM and MFR-L, subject to the Use-Specific standards for Accessory Dwelling Units.”
    One more reviewed finding on this topic
    • Allowed (with conditions) — Accessory dwelling units in the SFR-1, SFR-2, SFR-3, RA, RE, RM, and MFR-L zone districts.
      “ADUs are permitted in some residential zone districts: SFR-1, SFR-2, SFR-3, RA, RE, RM and MFR-L, subject to the Use-Specific standards for Accessory Dwelling Units.”
  • Subdividing landRegulated (with conditions)

    Subdivision plats and related land-use applications in Los Alamos County.

    • Subdivision plats are reviewed by the Planning and Zoning Commission in the quasi-judicial process.
    • Summary plats may be handled administratively when they meet the stated limited conditions.
    “The Planning and Zoning Commission reviews and approves Quasi-judicial applications. Examples or projects that would need reviewed by the Commission include conditional use permits, development plans, subdivision plats, and variances.”
  • Permit feesPublished (with conditions)

    Los Alamos County residential building permit and plan-review fees.

    • The plan-review fee is 65% of the building permit fee.
    • Additional plan review caused by changes, additions, or revisions is charged hourly.
    • Outside consultants are charged at actual cost.
    • Standard inspections are included, but re-inspections and inspections outside normal business hours may incur additional charges.

    plan review fee: 65 percent of building permit fee · additional plan review: 47 USD per hour (or the hourly cost to the County, whichever is greater)

    “A plan review fee must be paid at the time of submitting documents for plan review. The plan review fee is 65% of the building permit fee as determined by the table below.”
    2 more reviewed findings on this topic
    • Published (with conditions) — Residential building permit plan review and related fees in Los Alamos County.
      “When you submit your documents, a fee will be collected for your plan review. The plan review fee is 65% of the building permit fee.”
    • Published (with conditions) — County planning, building, and utility-related development fees.
      “Planning Fees: Based on project type (site plan, CUP, zone change) Building Permit Fees: Based on construction value Utility Connection Fees: Water, sewer, electric”
  • Permit processPublished (with conditions)

    Residential building-permit applications administered by the Los Alamos County Building Safety Division.

    • Applicants should not begin construction before obtaining the permit; doing so may result in double fees and required removal of work for inspection purposes.
    • Two sets of building plans and site plans must be provided for plan review.
    • Permit technicians and department staff review applications after receipt.
    • Most residential permits take three business days to process.
    • If additional information is needed, the county will contact the applicant.
    • After approval, the permit technician collects fees and issues the permit.
    • Construction may begin after the permit is issued; required inspections must be scheduled, and a Certificate of Occupancy is issued if the inspection is passed.

    typical residential processing time: 3 business days (most residential permits) · building and site plan sets: 2 sets (provided for plan review)

    “Two sets of the building plans and the site plans must be provided for plan review. [...] Most residential permits take three business days to process.”
    One more reviewed finding on this topic
    • Published (with conditions) — Residential building permit application process in Los Alamos County.
      “After we've received your application, a Permit Technicians and department staff member will review it. Most residential permits take three business days to process.”

New Mexico rules that apply here

  • 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.”
  • 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”
  • Who permits septicState

    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 NMAC identifies the New Mexico Environmental Improvement Board as the issuing agency and defines the department as the New Mexico Environment Department.
    • More stringent city or county requirements may also apply.

    maximum regulated flow: <= 5000 gallons per day (Systems requiring a discharge plan under 20.6.2 NMAC or an NPDES permit are outside this part.)

    “20.7.3.1 ISSUING AGENCY: New Mexico Environmental Improvement Board.”
    3 more reviewed findings on this topic
    • State (with conditions) — Onsite wastewater and septic-system regulation applicable in Los Alamos County.
      “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.”
    • State — Onsite wastewater and septic-system administration applicable in New Mexico, including Los Alamos County.
      “The Onsite Wastewater Bureau ensures septic systems are adequately installed and maintained in a manner that is protective of public health and the environment.”
    • State — Onsite wastewater and septic systems in Los Alamos County under New Mexico administration.
      “The Environmental Health Bureau (EHB) regulates food facilities and food manufacturers, onsite wastewater systems (septic systems), and all public aquatic venues in New Mexico. EHB protects the health and safety of New Mexico’s residents and guests by permitting, inspecting, and providing technical assistance to operators and homeowners.”
  • Septic permitRequired

    Conventional onsite liquid-waste systems serving a qualified homeowner’s personal residence in Los Alamos County.

    • The homeowner must qualify by passing the NMED exam.
    • The permit applies to a conventional system serving the qualified homeowner’s personal residence.
    • The homeowner cannot install or modify a system serving a rental unit or other property that is not the homeowner’s personal residence.
    • A qualified homeowner may install no more than one system during a twelve-month period.
    • The permit to construct is issued after approval and payment; installation must occur within one year after becoming a qualified homeowner.
    • The published homeowner fees are $170 for the qualification application and $225 for a permit or registration for 1,000 gallons per day or less.

    homeowner qualification fee: 170 USD · liquid waste permit or registration fee: 225 USD (for 1,000 gpd or less)

    “Qualified Homeowners can then submit an application for Liquid Waste Permit or Registration to the local field office for review. After the application is approved, you will receive two invoices totaling $395, usually by e-mail. Remember you are paying for both the Application for Homeowner Qualification Certificate ($170) and the Application for Liquid Waste Permit or Registration ($225 for 1,000 gpd or less).”
    3 more reviewed findings on this topic
    • Required — New or modified onsite liquid-waste systems in Los Alamos County.
      “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.”
    • Required — Construction or modification of a conventional onsite liquid-waste system serving a qualified homeowner's personal residence.
      “After paying the fee, your Permit to construct will be issued, and you have one year to install the system after becoming a qualified homeowner.”
    • Required — 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.
      “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.”
  • 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.”
    3 more reviewed findings on this topic
    • Required — Onsite liquid-waste installations, modifications, and qualifying property transfers in Los Alamos County.
      “All Homeowner installations require an NMED final inspection.”
    • Required — Homeowner-installed onsite liquid-waste systems under the New Mexico Environment Department program.
      “All Homeowner installations require an NMED final inspection.”
    • Required — Homeowner-installed onsite liquid-waste systems in Los Alamos County.
      “Before covering the system – Final inspection (required) All Homeowner installations require an NMED final inspection.”
  • 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.”
    One more reviewed finding on this topic
    • Limited — Off-grid sanitation and onsite liquid-waste disposal in Los Alamos County.
      “No person shall discharge untreated liquid waste except into a permitted and approved enclosed system, a permitted and approved liquid waste treatment unit or a public sewer system, except for the discharge of graywater pursuant to 20.7.3.810 NMAC.”
  • Mandatory utility hookupConditional

    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.

    • A public sewer is deemed available when it has capacity and is located in a thoroughfare, right-of-way, or easement abutting the lot.
    • The on-site system must be properly abandoned within 30 days after connection.
    • The state rule does not itself identify which local authority will require connection.

    abandonment deadline after sewer connection: 30 days

    “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.”
    One more reviewed finding on this topic
    • Conditional — Connection of residences or commercial units using onsite wastewater to public sewer where sewer is available and local authority requires connection.
      “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.”
  • 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;”
    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.”
    • 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”
  • 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.”
  • 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.”
  • 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;”
    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;”
  • 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.”
    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.”

Still unanswered

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

  • Lot coverage — Lot coverage in Los Alamos County zoning districts.
  • Camping on your land — Temporary camping on private land or outside designated county campgrounds.
  • Well permit — Private well permitting in Los Alamos County.
  • Short-term rentals — Short-term rental use in Los Alamos County.

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.

Living off-grid in Los Alamos County, New Mexico

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

Los Alamos County scores 42/100 on the Bolthole Index, a marginal county profile. Its strengths: 85.3% federal land exposure and sparse surroundings — about 24,658 people within a 30-minute drive. Watch-outs: thin water margin (18″/yr rainfall) and higher long-term carry cost.

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

Los Alamos County generally requires a residential building permit, and it enforces county zoning. Onsite septic is permitted by New Mexico Environment Department, Onsite Wastewater (Liquid Waste) Program. Owner-builders may act as their own contractor to build their home. These answers are quoted from official sources and independently re-checked. Rules change and cities within the county differ — always confirm with the county before you buy or build.

How much does land cost in Los Alamos County, New Mexico?

Land in Los Alamos County runs about $24,134 per acre, based on the latest county data.

What is the water situation in Los Alamos County?

Los Alamos County gets about 18" of rain a year, with severe drought in roughly 37.1% of years.

How remote is Los Alamos County?

A representative private-land location has about 24,658 people within a 30-minute drive and 1,282,252 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.

How Los Alamos compares in New Mexico

Compare side-by-side →See all 33 New Mexico counties ranked →