Bolthole Index

Costilla County, Colorado

Building permits, zoning and land rules in Costilla County, Colorado

69Index Score / 100
#2 of 64 in Colorado

Unincorporated Costilla County, Colorado requires building permits for all new structures and has zoning districts with minimum lot sizes12. Costilla County Planning and Zoning handles septic permits for systems of 2,000 gallons per day or less; unsewered buildings need OWTS approval before building or occupancy approval34. Inside San Luis, the town handles building permits and zoning, while OWTS requirements still apply through the local public health agency564.

At a glance

Building permit
Required for all new structures; the county has adopted the 2018 IRC and permits must be renewed annually17
Zoning
Yes, with Agricultural (A) and Estate Residential (ER) districts, each with its own minimum lot size2
Septic (OWTS) permits
Required before installation, alteration or repair and before building approval for unsewered structures; county-issued at 2,000 gpd or less43
Owner-builder exemption
Repair or maintenance on your own property has a narrow state licensing exemption; no general new-home exemption is confirmed89
Manufactured homes
Must be 1976 or newer to be allowed in Costilla County7
Design criteria
Countywide snow load 30 lbs/sq ft, wind load 115 mph7
35-acre subdivision exemption
Parcels of at least 35 acres each, not intended for multiple owners, are exempt from Colorado's subdivision review10
Septic soil difficulty
About 34.6% of county soils are rated not limited for conventional drain fields; a site evaluation still matters11

Who to call

Planning & zoning

Costilla County Planning and Zoning Department

Building permits, zoning permits, physical addressing, and OWTS (septic) soil evaluations and permits for unincorporated Costilla County

(719) 937-7668

400 Gaspar Street, PO Box 130, San Luis, CO 81152

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 Costilla County, Colorado?

All new structures in any zone district in unincorporated Costilla County require a county building permit, and an OWTS permit and water source must be in place before an occupancy permit is issued1. Unsewered structures also need local public health agency OWTS approval before building approval4. Inside San Luis, the town issues building permits for single-family and multi-family dwellings after approving a plot plan; OWTS approval remains with the local public health agency54. Costilla County has adopted the 2018 International Residential Code as its building code, along with its own design criteria: a countywide snow load of 30 pounds per square foot and a wind load of 115 miles per hour7. Permits here don't last forever: construction permits must be renewed annually, and the Land Use Administrator has discretion to issue up to 3 annual permits for a property, with a 4th permit requiring a variance request to the Board of County Commissioners7. Manufactured homes face their own age rule, stated plainly on the county's page: manufactured homes must be 1976 or newer to be allowed in Costilla County7. Colorado's own framework explains why the county sets these rules itself: the state is a "local control" state, so decisions like building-code adoption are made by the county rather than through a uniform statewide code12.

Who issues building, zoning and septic permits in Costilla County, and how do you reach them?

The Costilla County Planning and Zoning Department is the office for building permits, zoning permits, physical addressing, and OWTS soil evaluations, located at 400 Gaspar Street, San Luis, Colorado 811527. Reach the office at (719) 937-7668; it is open 7:00 a.m. to 5:30 p.m., Monday through Thursday, with no closure for lunch7. Building inspections are scheduled by calling the Planning and Zoning Office at that same number7. The department asks buyers to contact it before purchasing land or starting a land-use activity in Costilla County7. For a physical address, bring the parcel's legal description and the owner's name as registered with the Costilla County Assessor; the fee is $20, and the county does not issue a physical address to vacant land7.

Does Costilla County have zoning?

The county's Land Use Code establishes zoning districts in unincorporated Costilla County, including Agricultural (A) and Estate Residential (ER), each with its own minimum lot size2. Colorado law gives counties authority to zone unincorporated territory, regulating building location, height, bulk, lot size, lot coverage, open space, population density, and land use by district13. Building height and story limits in Colorado are set at the local level rather than by a statewide number, so the applicable local zoning ordinance controls what you can build on a given lot14. One state rule matters if you're buying a larger tract with an eye toward splitting it later: a division of land into parcels of at least 35 acres each, none intended for use by multiple owners, is excluded from Colorado's subdivision definition10. Confirm the zoning district and minimum lot size for your specific parcel with the Planning and Zoning Department before you buy7. Inside San Luis, town zoning governs uses and structures; OWTS approval still comes from the local public health agency64.

How do OWTS (septic) permits work in Costilla County?

Costilla County Planning and Zoning issues OWTS (septic) permits for systems with a design capacity of 2,000 gallons per day or less, using the county application under Colorado Regulation 433. Before installing, altering or repairing an OWTS, obtain local public health agency approval and submit property, site-and-soil and system-design information415. For unsewered structures, OWTS permit and inspection approval are prerequisites to building or occupancy approval, so resolve septic early with Planning and Zoning43. Systems above 2,000 gallons per day also face state site-location, design-approval and discharge-permit requirements4. A final inspection is required before a permitted system goes into use16. Local septic fees are capped at agency costs, with a $23 state surcharge for each new, repaired or upgraded system permit17. Colorado prohibits new cesspools and requires adequate sewage disposal for occupied structures without sewer service18. About 34.6% of Costilla County soils are rated not limited for conventional drain fields; that countywide rating does not replace a parcel-specific site evaluation1115.

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

We could not confirm a Costilla County rule for living in an RV on a residential parcel; ask the Planning and Zoning Department before buying land for that purpose7. Colorado-regulated tiny homes can be approved for long-term living, but plans must go to the Colorado Division of Housing before construction, the home must meet applicable codes and local zoning, and certification applies to the installation site19. Costilla County separately says temporary cargo and shipping containers are allowed only during construction7. Manufactured homes have a clearer local rule: Costilla County requires them to be 1976 or newer, while Colorado allows a HUD-code home to be installed where local zoning permits it720. Acting as your own builder does not create a general exemption from new-home rules: the confirmed state exemption covers repair or maintenance on your own property, not construction of a new residence89.

What are the steps to building a home in Costilla County?

  1. Contact Costilla County Planning and Zoning at (719) 937-7668 before purchasing land or starting a land-use activity7.
  2. Confirm the parcel's zoning district and minimum lot size; inside San Luis, use the town's zoning and plot-plan approval process for residential building permits265.
  3. For an unsewered home, resolve the site-and-soil evaluation and OWTS approval before building approval with the local public health agency; Costilla County Planning and Zoning handles county OWTS applications4153.
  4. If you need a well, apply to Colorado's Division of Water Resources; complete applications can take up to 49 days to review, and an augmentation plan may be needed21.
  5. Apply for the county building permit using the adopted 2018 IRC and county design criteria, and renew construction permits annually7.
  6. For direct state-highway access, apply to CDOT; a Level 1 single-family residential or agricultural access permit costs $5022.
  7. Arrange final OWTS inspection before using the system, and have the OWTS permit and water source in place before county occupancy approval161.

What to check before you buy land in Costilla County

Before buying Costilla County land, confirm a usable water source with Colorado's Division of Water Resources: new groundwater-diverting wells require a permit, subject to statutory exemptions and basin-specific rules, and an augmentation plan may be needed21. A tract divided into parcels of at least 35 acres each, none intended for multiple owners, is excluded from Colorado's subdivision definition; that exemption does not establish the parcel's zoning district or minimum lot size102. Ask Planning and Zoning about the parcel before purchasing7. About 34.6% of county soils are rated not limited for conventional drain fields, but an OWTS application still requires site-and-soil information1115. Costilla County averages about 17.5 inches of annual precipitation, with severe drought in about 34.2% of years2324. The effective property tax rate is about 0.3%, with a median annual bill near $531 and a typical home value around $184,317252627.

Watch-outs

  • New groundwater-diverting wells require a Colorado Division of Water Resources permit, subject to statutory exemptions and basin-specific rules; confirm the applicable conditions before relying on a parcel having a viable well21.
  • We could not confirm Costilla County's rule for living in an RV on a residential parcel, so ask Planning and Zoning before buying land for that purpose7.
  • Colorado's confirmed owner exemption is limited to repair or maintenance on the owner's property; it does not establish a general exemption for building a new residence, so ask Costilla County Planning and Zoning what permits and contractor requirements apply897.

Sources

  1. Costilla County Planning and Zoning Department (2026 county census)
  2. Costilla County Land Use Code (Division 1 Zoning) (2026 county census)
  3. Costilla County OWTS Application (2026 county census)
  4. Code of Colorado Regulations, Regulation 43 — On-Site Wastewater Treatment System Regulation, quoted and re-checked
  5. Town of San Luis: San Luis Municipal Code 21.15.060—Plot Plan (Costilla County), quoted and re-checked
  6. Town of San Luis: SLMC 21.07.010 - General Provisions (Costilla County), quoted and re-checked
  7. Costilla County Planning and Zoning Department (costillacounty.gov)
  8. Colorado Revised Statutes 2026, Title 30, § 30-11-125 (2026 county census)
  9. Colorado Revised Statutes 2026, Title 30, § 30-11-125 (Colorado statewide rule), quoted and re-checked
  10. Colorado Revised Statutes 2024, Title 30—Government—County (Colorado statewide rule), quoted and re-checked
  11. 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
  12. Land Use Planning and Regulation in Colorado (Colorado statewide rule), quoted and re-checked
  13. Colorado Revised Statutes 2025 Title 30 Government - County (Colorado statewide rule), quoted and re-checked
  14. Colorado Revised Statutes 2024, Title 31 — Government - Municipal (Colorado statewide rule), quoted and re-checked
  15. Code of Colorado Regulation 5 CCR 1002-43, quoted and re-checked
  16. Title 25 - Public Health and Environment - Colorado Revised Statutes 2024 (Colorado statewide rule), quoted and re-checked
  17. Code of Colorado Regulations, Regulation 43 — On-Site Wastewater Treatment System Regulation, quoted and re-checked
  18. content.leg.colorado.gov (Colorado statewide rule), quoted and re-checked
  19. Consumers of Manufactured Homes and Tiny Homes - HUD (Colorado statewide rule), quoted and re-checked
  20. Consumers of Manufactured Homes and Tiny Homes - HUD (Colorado statewide rule), quoted and re-checked
  21. Water Administration (Colorado statewide rule), quoted and re-checked
  22. Access Permits | Frequently Asked Questions (Colorado statewide rule), quoted and re-checked
  23. Annual precipitation: Bolthole Index county data
  24. Share of years in severe drought: Bolthole Index county data
  25. Effective property tax rate: Bolthole Index county data
  26. Median property tax bill: Bolthole Index county data
  27. Typical home value (Zillow): Bolthole Index county data

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, Costilla County requires a building permit for a home.

RuleCostilla CountyAlamosa CountyHuerfano CountyConejos CountyCuster CountyRio Grande CountyPueblo County
Building permitRequiredRequiredRequiredRequiredRequiredRequiredRequired
County zoningYesYesYesYesYesYesYes
Septic permitsCounty Planning & ZoningCounty Land Use & Building Dept.Las Animas-Huerfano Counties District Health Dept.County Land UseCounty Planning & ZoningCounty Dept. of Building SafetyPueblo Dept. of Public Health & Env.

County locator

Costilla County in Colorado

69
County map
Costilla County highlighted among the Colorado counties · colored by Index score

How Costilla County scores

Seclusion88100% ev.
Self-Sufficiency46100% ev.
Admin Boringness4190% ev.
Durability51100% ev.
Property Autonomy75100% ev.
Carry Cost90100% ev.

Evidence strength: 98%. This reports direct-source completeness and fallback use; it is separate from the score and is not a confidence interval. How it works →

$184kTypical home
0.3%Property tax
$996Land / acre
17.5"Annual rain
34.2% of yrsSevere drought
0 / yr (+0)Mid-century 100°F days
24.1 daysMid-century dry spell
0.98" (+2%)Mid-century 1-day rain
1.34×Wildfire change factor
100%Forward climate coverage
$1,614Home insurance / yr
3.2% / yrInsurance growth
1.15%Nonrenewal rate
county median (2+ published ZIPs)Insurance basis
71,853People within 2 hr
2,190Radius comparison (15 mi)
3People / sq mi
23.9%Federal land
58.6%Land at 15% slope or less
34.6%Soils rated "not limited" for septic (strict USDA rating)
270,471 acWorkable land screen
36.2%Wooded land
29.1 tonsBiomass / forest ac
42.5°FAvg temp

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Cities and towns in Costilla 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.

Not yet researched: Town of Blanca

Answers from the rulebook for Costilla County

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

Costilla County rules

  • County-wide zoningPresent

    The county Land Use Code establishes zoning with districts including Agricultural (A) and Estate Residential (ER), each with minimum lot sizes.

    Costilla County Land Use Code (Division 1 Zoning) ↗Scouted from the county site, not yet independently re-checked

Colorado rules that apply here

  • Building permitRequired

    Construction, including adding previously unlicensed space to a Health Facility license, or operational permits for a Colorado-licensed Health Facility located in a jurisdiction with no local Building Department.

    • The Division is responsible for issuing the building permit when no local Building Department exists.
    • Limited Scope Project permits may be used instead of an individual Building, Fire, or Life Safety Code permit for projects identified by the Division.
    • Permit issuance is contingent upon review and approval by the Fire Code Official.
    • The determination of when a building permit is required is based on International Building Code Section 105 requirements, except Sections 105.1.1 and 105.1.2.
    • Substantial changes to the project scope, including adding square footage, require a new permit application.
    • Once all corrections identified through code review are satisfactorily addressed, the Division will issue the permit.

    building permit determination: International Building Code Section 105, except Sections 105.1.1 and 105.1.2 (Substantial changes to project scope require a new permit application.)

    “Under these circumstances, the Division will issue the applicable Building Permits and associated Certificates of Occupancy”
    One more reviewed finding on this topic
    • Limited — Construction, renovation, emergency, cash-funded, or in-house-funded projects involving Colorado state buildings and administered through the Department of Personnel and Administration/Office of the State Architect.
      “State Buildings Program (SBP) is responsible for establishing minimum building codes for all construction by state agencies [...] Colorado has no statewide building code”
  • Owner-builder exemptionConditional

    An individual owner performing repair or maintenance work on the owner's property in a Colorado county that has adopted a building-contractor licensing program under C.R.S. § 30-11-125.

    • The statute addresses county building-contractor licensing programs and applies to work in unincorporated county areas when a county has adopted such a program.
    • The exemption is limited to repair or maintenance work on the individual's own property; it does not establish a statewide exemption for constructing a new residence or for all contractor-regulated work.
    • A county may require a building-contractor license for persons engaging in the business of being a building contractor in its unincorporated areas.
    • The statute defines a building contractor as a person who, for compensation, directs, supervises, or undertakes work for which a county building permit is required.
    • The statute source states that § 30-11-125 was effective August 3, 2007, and was amended effective October 1, 2019.
    “Nothing [...] shall be construed to require any individual to hold a license to perform repair or maintenance work on his or her own property”
    2 more reviewed findings on this topic
    • Conditional — An individual performing electrical work on the individual's own Colorado property or residence, including a primary residence, under the statewide electrical licensing statute.
      “Nothing in this article 115 [...] require any individual to hold a license”
    • Conditional — An individual performing plumbing work on the individual's own Colorado property or residence, including a primary residence, under the statewide plumbing licensing statute.
      “Nothing in this article 155 requires an individual to hold a license”
  • Building code adoptedPartial

    Construction at Colorado state agencies and institutions of higher education owned facilities.

    • The approved state building codes are minimum requirements for the specified state-owned facilities.
    • The source states that additional codes, standards, and appendices may be adopted by state agencies and institutions in addition to the listed minimum codes and standards.
    • The statewide source describes Colorado as a local-control state in which most building-code adoption decisions are driven by local governments, not the state.
    • The listed code editions and effective dates are those stated in the retrieved Approved State Building Codes document, which is marked Rev. 9/2023.

    International Building Code edition: 2021 edition (Chapter 1 as amended; Chapters 2-35 and Appendices C and I) · International Residential Code edition: 2021 edition (As applicable) · International Energy Conservation Code edition: 2021 edition (As adopted by the Colorado State Buildings Program and Colorado Energy Office) · National Electrical Code edition: 2023 edition (Effective July 30, 2023) · Colorado Model Electric Ready and Solar Ready Code effective date: 2023-07-01 date · International Plumbing Code edition: 2021 edition (First printing (March 2020); effective May 15, 2023 as adopted by the Colorado Examining Board of Plumbers) · International Fuel Gas Code edition: 2021 edition (First printing; effective May 15, 2023 as adopted by the Colorado Examining Board of Plumbers)

    “These minimum requirements are to be applied to all construction at state agencies and institutions of higher education owned facilities.”
    One more reviewed finding on this topic
    • Partial — Construction at Colorado state agencies and institutions of higher education owned facilities under the Colorado State Buildings Program and other state authorities.
      “Approved building codes and standards are adopted by the Office of the State Architect (herein referred to as State Buildings Program (SBP)) and other state authorities, and are identified below. These minimum requirements are to be applied to all construction at state agencies and institutions of higher education owned facilities.”
  • InspectionsRequired

    All reviewed Colorado State Buildings Program construction projects subject to state building-code compliance review.

    • The policy states that all reviewed construction projects are inspected for building-code compliance.
    • Required inspections are identified on the Building Inspection Record and may include building, special, fire, plumbing, electrical, boiler, elevator, and health-department inspections as applicable.
    • Local fire districts and other state authorities may have separate inspection responsibilities.
    • The policy applies to state buildings and state projects, not uniformly to every private project in Colorado.
    “All reviewed construction projects shall be inspected for building code compliance.”
  • Minimum lot sizeDistrict specific (with conditions)

    County zoning regulations for unincorporated Colorado; the state statute authorizes local district-specific lot-size rules but does not prescribe one statewide minimum.

    • Applies to portions of counties outside incorporated cities and towns.
    • Actual minimum lot sizes must be obtained from the applicable county zoning resolution and district map.
    • Colorado's official planning guidance states that most zoning decisions are driven by local governments, not the state.
    “Colorado is a “local control” state when it comes to land use planning authority (Local Government, 2012). This means that most land use decisions such as adoption of zoning and building codes are driven by local governments, not by the state.”
  • Building heightDistrict specific (with conditions)

    Municipal zoning districts in Colorado where the municipality adopts building-height or story regulations.

    • The applicable height or story limit is determined by the municipality's zoning regulations and district classification.
    • The statute provides authority but no statewide numeric height limit.
    • Height restrictions do not apply to existing buildings under the cited municipal zoning authority, except as stated for new growth of vegetation.

    building height or number of stories: local regulation (No statewide numeric limit specified)

    “the governing body of each municipality is empowered to regulate and restrict the height, number of stories, and size of buildings and other structures”
  • Tiny homesAllowed (with conditions)

    Colorado Division of Housing-regulated tiny homes intended for residential occupancy and long-term living.

    • Plans must be submitted to the Colorado Division of Housing for approval before construction of the units.
    • The unit must satisfy applicable Colorado-adopted codes and standards and local zoning requirements.
    • Tiny home units are certified for the specific site where installed; relocation to another Colorado site requires the applicable design criteria, and design differences require revisions.

    foundation types: permanent or temporary

    “Tiny homes are approved for long term living”
  • Manufactured homesAllowed (with conditions)

    Installation and resulting residential use of HUD-code manufactured homes and mobile homes in Colorado, subject to Colorado Division of Housing requirements and local zoning or building requirements.

    • HUD homes must be certified by the applicable State Administrative Agent for installation in Colorado; imported units are monitored by the State Administrative Agent of the state from which they are imported, rather than necessarily by Colorado's SAA.
    • A HUD home may be installed anywhere in Colorado only where local zoning allows it.
    • Local jurisdictions may require site mitigation to meet local wind and snow loads, but the mitigation cannot directly affect or change the construction of the home itself.
    • The Division of Housing regulates installation and installation inspections for HUD homes; mobile-home foundation and structural construction requirements are regulated by local jurisdictions with active building departments.
    • The state minimum HUD design criteria listed by the source are Wind Zone 1, Thermal Zone 3, and Middle Roof Load Zone (30 psf).

    wind zone: 1 zone · thermal zone: 3 zone · roof load zone: 30 psf (Middle Zone)

    “HUD homes [...] can be installed anywhere in Colorado as long as the local zoning allows for it.”
  • Accessory dwellingsAllowed (with conditions)

    One accessory dwelling unit as an accessory use to a single-unit detached dwelling in a Colorado subject jurisdiction where single-unit detached dwellings are allowed.

    • The rule applies to a subject jurisdiction: either a municipality with a population of at least 1,000 within a metropolitan planning organization, or the portion of a county within a census-designated place of at least 40,000 people that is also within a metropolitan planning organization.
    • The subject jurisdiction must allow the ADU through an administrative approval process.
    • The rule applies on or after June 30, 2025.
    • The state requirement does not establish that every Colorado municipality or county area is a subject jurisdiction.

    maximum required ADUs per single-unit detached dwelling: 1 unit · effective date: >= 2025-06-30 · qualifying municipality population: >= 1000 persons (municipality must also be within a metropolitan planning organization) · qualifying census-designated-place population: >= 40000 persons (county portion must also be within a metropolitan planning organization)

    “Section 1 requires a subject jurisdiction, on or after June 30, 2025, to allow, subject to an administrative approval process, one accessory dwelling unit”
  • Who permits septicMixed

    On-site wastewater treatment systems statewide in Colorado.

    • The state establishes minimum standards through the Water Quality Control Commission.
    • Every local board of health must adopt detailed OWTS rules within its jurisdiction.
    • Local public health agencies and local boards of health have primary enforcement responsibility; the department may assume functions if a local agency substantially fails to administer and enforce the law.
    “Every local board of health in the state shall develop and adopt detailed rules for on-site wastewater treatment systems within its area of jurisdiction.”
  • Septic permitRequired

    On-site wastewater treatment systems in Costilla County under Colorado Regulation 43.

    • Before installing, altering, or repairing an OWTS, the applicant must obtain a permit from the local public health agency.
    • Systems with design capacity less than or equal to 2,000 gallons per day are governed by local board of health regulations under Regulation 43 and the OWTS Act.
    • Systems greater than 2,000 gallons per day are also subject to state site-location, design-approval, and discharge-permit requirements.
    • No city, county, or city and county may issue a building or occupancy permit for an unsewered structure until the local public health agency has issued or approved the applicable OWTS permit and inspection.

    design capacity: <= 2000 gallons per day (Local board of health regulations apply under Regulation 43 and the OWTS Act.) · design capacity: > 2000 gallons per day (State site-location, design-approval, and discharge-permit requirements also apply.)

    “Prior to installing, altering, or repairing a system, the applicant must obtain a permit from the local public health agency.”
    2 more reviewed findings on this topic
    • Required — On-site wastewater treatment systems in Costilla County and elsewhere in Colorado before installation, alteration, or repair.
      “Prior to installing, altering, or repairing a system, the applicant must obtain a permit from the local public health agency.”
    • Required — Construction, alteration, installation, repair, or use of an OWTS statewide when the building or structure is not serviced by a sewage treatment works.
      “Constructs, alters, installs, or permits the use of any on-site wastewater treatment system without first applying for and receiving a permit as required under this article;”
  • Septic inspectionRequired

    OWTS construction, installation, alteration, or repair statewide before the system is placed in use, plus operating inspections when authorized under applicable rules.

    • A final inspection must occur after permitted work is completed and before the system is placed in use.
    • The local public health agency or its designated professional engineer determines compliance with the permit, statute, and applicable rules.
    • For a building not serviced by a sewage treatment works, an occupancy permit requires final OWTS inspection and local agency approval.
    “Final inspection of a system to be made by the local public health agency or its designated professional engineer after construction, installation, alteration, or repair work under a permit has been completed, but before the system is placed in use, to determine that the work has been performed in accordance with the permit and that the system is in compliance with this article and the rules adopted under this article;”
  • Off-grid sanitationLimited

    Sanitation for dwellings and occupied structures statewide that is provided without connection to a sewage treatment works.

    • The structure must have adequate facilities for sanitary disposal of sewage.
    • An OWTS may be used subject to applicable permit, inspection, construction, installation, alteration, and use requirements.
    • Construction of new cesspools is prohibited.
    • Septage removed during maintenance or cleaning must be disposed of at an approved site and in an approved manner.
    “No person shall construct or maintain any dwelling or other occupied structure that is not equipped with adequate facilities for the sanitary disposal of sewage.”
  • Well permitRequired

    Every new groundwater-diverting well in Colorado, including residential wells, subject to statutory exemptions and basin-specific rules.

    • The Division of Water Resources administers groundwater permitting and issues permits.
    • Applicants must complete the appropriate application and pay the associated fee.
    • Statutory exemptions and additional Denver Basin or Designated Basin rules may affect the requirement or permit conditions.
    • In many areas, a well may also require an augmentation plan if its priority is not sufficient to divert in priority.

    complete-application review time: <= 49 days (DWR states review of complete new and replacement applications may take up to 49 days)

    “Every new well in the state that diverts groundwater must have a well permit.”
  • Mandatory utility hookupConditional

    Residential or other occupied structures statewide that are not serviced by a sewage treatment works.

    • Colorado law conditions building and occupancy permitting on either service by a sewage treatment works or an approved OWTS process.
    • If the structure is not serviced by a sewage treatment works, the local public health agency must issue the OWTS permit before building construction or remodeling approval, and must complete a final inspection and approve the installation before occupancy approval.
    • This claim does not establish a universal statewide mandate to connect to a particular municipal water or sewer provider.
    “A permit to construct or remodel a building or structure that is not serviced by a sewage treatment works until the local public health agency has issued a permit for an on-site wastewater treatment system;”
  • Subdividing landRegulated (with conditions)

    Division of land and creation of interests subject to Colorado county subdivision law.

    • Divisions creating parcels of at least 35 acres each are excluded when none is intended for use by multiple owners.
    • Additional statutory exclusions include certain 35-acre-per-interest divisions, court or eminent-domain divisions, security instruments, investment entities, cemetery lots, severed mineral or water interests, certain joint-tenancy or tenancy-in-common interests, parcel combinations, contingent sale contracts, and cluster developments.
    • A board of county commissioners may exempt a division from the subdivision definition by rule, regulation, or resolution if it determines the division is not within the purposes of the subdivision statute.
    • Local county subdivision regulations and review procedures still determine administration.

    parcel-size exclusion: >= 35 acres (Each parcel must be at least 35 acres and none may be intended for use by multiple owners.) · minimum area per interest for listed exclusion: >= 35 acres per interest (Subject to the statutory exceptions and anti-evasion language.)

    “"Subdivision" or "subdivided land" means any parcel of land in the state which is to be used for condominiums, apartments, or any other multiple-dwelling units, unless such land when previously subdivided was accompanied by a filing which complied with the provisions of this part 1 with substantially the same density, or which is divided into two or more parcels, separate interests, or interests in common, unless exempted under paragraph (b), (c), or (d) of this subsection (10).”
  • Driveway accessRequired

    Direct residential access from a property to a Colorado state highway, and construction, relocation, closure, modification, or change in use of access points to state highways.

    • Direct access from a house to a state highway requires an access permit.
    • Some state-highway access categories require access from a lesser street or by easement from a parent parcel whenever possible.
    • Level 1 permits cover single-family residential/agricultural permits; Level 2 covers commercial property and developments exceeding 20 vehicular trips per day without roadway improvements; Level 3 covers commercial property requiring roadway improvements.
    • Level 1 fees are $50, Level 2 fees are $100, and Level 3 fees are $300.
    • No fees are charged to local government applications or political subdivisions.
    • There is no upfront charge to review an Access Permit Application.
    • The permittee is responsible for roadway-improvement costs required with issuance of an access permit.
    • Performance-bond requirements apply only to private projects; local agencies are not required to comply, although CDOT regions may require a bond at their discretion.

    Level 1 access permit fee: 50 USD (Single-family residential/agricultural permits) · Level 2 access permit fee: 100 USD (Commercial property permits and developments exceeding 20 vehicular trips per day without roadway improvements) · Level 3 access permit fee: 300 USD (Commercial property permits requiring roadway improvements)

    “If you want the house to have direct access off of the state highway, then you will need an access permit.”
  • Building in a floodplainRequired

    Development in floodplain areas subject to Colorado floodplain-management requirements, and state-owned land in counties or municipalities that do not participate in the National Flood Insurance Program.

    • Local floodplain regulations must equal or exceed FEMA National Flood Insurance Program minimum design and construction criteria.
    • Local floodplain regulations must comply with Colorado Water Conservation Board rules and regulations for regulatory floodplains.
    • The state program applies to development on state-owned land in counties and municipalities that do not participate in the National Flood Insurance Program.
    “Local government floodplain management regulations for development in floodplain areas must equal or exceed the federal emergency management agency's national flood insurance program's (national flood insurance program) minimum design and construction criteria and must comply with the Colorado water conservation board's (CWCB) rules and regulations for regulatory floodplains in Colorado.”
  • Short-term rentalsLimited

    Short-term rentals statewide, defined in the cited official source as lodging-unit rentals for fewer than 30 days.

    • There is no statewide STR regulatory scheme.
    • Boards of county commissioners may license and regulate STR owners or agencies and set license fees, terms, issuance, and revocation procedures.
    • Home-rule municipalities and private contracts or homeowners' association covenants may impose additional restrictions.

    maximum rental duration for STR definition: < 30 days

    “There are no statewide regulations regarding STRs. As established through House Bill 20-1093, state law allows for boards of county commissioners (BOCCs) to license and regulate an owner or owner’s agency and to fix the fees, terms, and manner for issuing and revoking licenses.”
  • Permit feesVariable (with conditions)

    OWTS permit and related inspection fees applicable in Colorado, including Costilla County, subject to local board of health schedules.

    • Local boards of health may set permit fees only up to actual direct and indirect agency costs.
    • Permit application fees must not exceed the statutory maximums in section 25-10-107, C.R.S.
    • A local board of health may provide for waiver of a normally required local OWTS permit fee.
    • The local public health agency must collect a $23 surcharge for each permit issued for a new, repaired, or upgraded OWTS; $3 is retained for administrative costs and $20 is transmitted to CDPHE.

    OWTS surcharge: 23 USD per permit ($3 retained by the local public health agency and $20 transmitted to CDPHE.)

    “A local board of health may set fees for permits. The permit fees may be no greater than required to offset the actual indirect and direct costs of the local public health agency. [...] The local public health agency must collect a fee of twenty-three dollars for each permit issued for a new, repaired, or upgraded OWTS.”
  • Permit processPartial

    Colorado's statewide legal framework for land-use permitting and development regulation.

    • Most land-use decisions, including building-code adoption, are driven by local governments rather than the state.
    • Local governments may develop permitting procedures and standards for development under 1041 regulations.
    • The cited statewide source does not establish a uniform statewide permit application, review, approval, or inspection procedure.
    “Colorado is a “local control” state when it comes to land use planning authority (Local Government, 2012). This means that most land use decisions such as adoption of zoning and building codes are driven by local governments, not by the state.”
  • Campground & park staysAllowed (with conditions)

    Temporary overnight camping, including parking a motor home or traveler, on land and water under the control of Colorado Parks and Wildlife, including state parks and state recreation areas.

    • The source addresses lands and waters under the control of the Division of Parks and Wildlife, not all public or private land statewide.
    • Camping includes parking a motor vehicle, motor home, or traveler for the apparent purpose of overnight occupancy.
    • A commission-issued permit may be required; the statute defines permits to include campground permits and electrical hookup permits.
    • The state may charge fees for required passes or permits for use of any state park or state recreation area where supervision, maintenance, or specified facilities warrant a fee.

    overnight occupancy: true (Camping definition includes the parking of a motor vehicle, motor home, or traveler for the apparent purpose of overnight occupancy.) · permit types: campground permits; electrical hookup permits

    “Develop state parks and state recreation areas suitable for such recreational activities as camping, [...] "Camping" means [...] the parking of a motor vehicle, motor home, or traveler”
  • county zoning authorityGeneral

    Colorado counties adopting zoning plans for all or any part of unincorporated territory.

    • The county planning commission may make the zoning plan; in a county having a county planning commission, it must do so upon order by the board of county commissioners.
    • The zoning plan may regulate districts or zones, including building location, height, bulk, size, lot coverage, lot size, open spaces, population density, building and land uses, and access to sunlight for solar energy devices.
    • The plan may include regulations for uses on or along storm or floodwater runoff channels or basins only when the channel or basin has been designated and approved by the Colorado water conservation board, to lessen or avoid hazards from storm or floodwaters.
    • The statute applies to unincorporated territory and does not describe incorporated cities or towns as within this county zoning grant.
    “zoning all or any part of the unincorporated territory within such county”
  • county building authorityGeneral

    Colorado counties adopting and enforcing building codes and requiring building permits in designated unincorporated areas.

    • A board of county commissioners may adopt a building code in all or part of the county, but the area must not be within the limits of an incorporated city or town.
    • Buildings or structures used solely to shelter agricultural implements, farm products, livestock, or poultry may be excepted from the building code and permit requirement.
    • Before adoption, the county planning commission may designate part or all of the county for the building code upon request from the board of county commissioners; the board must hold a public hearing and publish notice once weekly for four consecutive weeks.
    • After adoption of the building code, construction, reconstruction, alteration, or remodeling in the designated area requires a building permit, except for the agricultural-shelter exception.
    • The board must fix a reasonable schedule of building-permit fees; no permit fee may be charged unless a qualified inspector actually performs an inspection.
    • Plans must conform to the building code, and plans and specifications generally must bear the seal of a Colorado-licensed architect or engineer unless exempted by section 12-120-403.
    • Every county adopting or updating a building code must adopt and enforce an energy code meeting or exceeding one of the three most recent International Energy Conservation Code versions under section 30-28-211.
    • The 2025 amendment to section 30-28-204 is effective January 1, 2026 and adds accessibility requirements for substantially amended or updated county building codes, with an exception for compliant one- and two-family dwellings and townhomes.
    “A board of county commissioners is authorized to adopt ordinances and a building code”

Still unanswered

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

  • Certificate of occupancy — Certificates or permits of occupancy in Costilla County
  • Local zoning — Aggregate local zoning across Costilla County municipalities and unincorporated areas
  • Zoning districts — Published zoning districts and district maps in Costilla County
  • Minimum dwelling size — Minimum dwelling size requirements in Costilla County
  • Setbacks — Building setbacks under Costilla County land-use regulations.
4 more unanswered
  • Lot coverage
  • Living in an RV
  • Camping on your land
  • Agricultural exemption

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 Costilla County

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

Over-appropriated / declining

The aquifer here is over-appropriated and declining. A domestic well is usually still permit-exempt, but long-term supply is a genuine risk.

Household wellExempt up to a limit

A household obtains water via a permit-exempt small-capacity well (15 gpm) under CRS 37-92-602 outside designated basins or CRS 37-90-105 inside them; on a 35-acre-plus lot limited outside/stock/1-acre irrigation is allowed.

Limit: Household-use-only well: 15 gpm, ≤0.33 acre-ft/yr, indoor only. Domestic well on a 35+ acre tract: 15 gpm, ≤1 acre-ft/yr.

Colorado DWR — Guideline 2023-1, Exempt & Small-Capacity Wells ↗
  • San Luis Valley / Rio Grande Basin (Water Division 3) — groundwater rules & RGWCD subdistrictsmajority of county

    Upper Rio Grande Basin governed by the 2021 Rules Governing Withdrawal of Groundwater in Division 3 and the Rio Grande Water Conservation District subdistricts (No. 1-6 + Trinchera). Confined and unconfined aquifers are over-appropriated; new consumptive appropriations are effectively unavailable, wells must replace injurious depletions, and subdistricts impose pumping curtailment/fees with State-Engineer curtailment for unresolved depletions.

    Colorado DWR — Designated Basins / Division 3 ↗

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 Colorado state water agency before you buy or drill.Groundwater governance as of Jul 2026, cited to each administering agency.

Living off-grid in Costilla County, Colorado

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

Costilla County scores 69/100 on the Bolthole Index, a strong county profile. Its strengths: manageable long-term carry cost and deep seclusion — about 2,190 people within 15 miles. Watch-outs: more administrative friction around building and land use.

Do you need a building permit in Costilla County, Colorado?

Costilla County generally requires a residential building permit, and it enforces county zoning. Onsite septic is permitted by Costilla County Planning and Zoning / Environmental Health (OWTS). 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 Costilla County, Colorado?

Land in Costilla County runs about $996 per acre, based on the latest county data.

What is the water situation in Costilla County?

Costilla County gets about 17.5" of rain a year, with severe drought in roughly 34.2% of years. On water rights, Costilla County lies in the San Luis Valley / Rio Grande Basin (Water Division 3) — groundwater rules & RGWCD subdistricts — Upper Rio Grande Basin governed by the 2021 Rules Governing Withdrawal of Groundwater in Division 3 and the Rio Grande Water Conservation District subdistricts (No. 1-6 + Trinchera). Confined and unconfined aquifers are over-appropriated; new consumptive appropriations are effectively unavailable, wells must replace injurious depletions, and subdistricts impose pumping curtailment/fees with State-Engineer curtailment for unresolved depletions..

How remote is Costilla County?

A typical private-land location has about 2,190 people within 15 miles and 183,373 within 100 miles. These radius catchments are the published fallback where road routing is unavailable.

How Costilla compares in Colorado

Compare side-by-side →See all 64 Colorado counties ranked →