Bolthole Index

Jefferson County, Colorado

Building permits, zoning and septic in the Town of Mountain View, Colorado

Most construction projects in the Town of Mountain View, Colorado require building permits and inspections; SAFEbuilt provides the town’s building and zoning services.1 Mountain View is in Jefferson County, whose Public Health office regulates septic systems.2 Mountain View allows qualifying accessory dwelling units, but RVs and other wheeled or transportable structures cannot serve as ADUs.3

At a glance

Building permits
Most construction projects require building permits and inspections through the town’s Building Department1
Zoning
Town zoning districts apply; SAFEbuilt provides planning and zoning services45
Septic systems
Jefferson County Public Health regulates onsite wastewater systems2
Accessory dwelling
Allowed on a qualifying residential parcel with an existing single-family dwelling; parcel minimum is 6,000 square feet3
Minimum ADU size
220 square feet of living space, excluding bathrooms and closets; this is an ADU minimum6
RV or manufactured ADU
RVs, travel trailers, mobile homes and manufactured housing cannot be used as ADUs3

Who to call

Building permits

Town of Mountain View Building Department (SAFEbuilt)

Building permit applications, project requirements and inspections inside town limits

(303) 450-8746

Zoning

Town of Mountain View Planning and Zoning (SAFEbuilt)

Town zoning requirements, setbacks and lot coverage; project planning assistance

(510) 612-2072

Septic permits

Jefferson County Public Health — Environmental Health Services

Septic-system regulation and guidance for properties in Jefferson County, including inside Mountain View

303-232-6301

100 Jefferson County Parkway, Golden, CO 80419

Contact details are copied from each office’s official page and were checked against it on October 12, 2026.

Off-grid gear

Going off-grid in Town of Mountain View means bringing your own water and power. The kit we’d start with:

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Do you need a building permit in the Town of Mountain View, CO?

Most construction projects in the Town of Mountain View require building permits and inspections to verify compliance with building codes and zoning regulations.1 Start with the town’s Building Department, served by SAFEbuilt, for the requirements for your particular project.1 Mountain View building permit applications and plans are processed through CommunityCore.1 Ask the Building Department for the required documents before preparing a submission, and budget for plan-review fees before review begins.1

Does the Town of Mountain View have zoning and ADU rules?

The Town of Mountain View publishes residential, commercial and Planned Development zoning districts, and SAFEbuilt provides the town’s planning and zoning services.45 Mountain View allows one ADU on a residential parcel with an existing single-family dwelling, subject to adopted building codes and a minimum parcel area of 6,000 square feet.3 The Mountain View ADU maximum is the lesser of 50% of the principal dwelling’s square footage or 650 square feet; the minimum is 220 square feet of living space, excluding bathrooms and closets.3 A Mountain View ADU cannot be sold separately or subdivided from the principal dwelling or parcel.3 We could not confirm district-specific lot sizes, setbacks, coverage or height limits here; ask Mountain View Planning and Zoning to review the parcel and proposed structure.5

How do septic permits work inside the Town of Mountain View?

Jefferson County Public Health regulates septic systems in Jefferson County, including systems inside the Town of Mountain View.2 Property owners may need a septic permit to install a new system, repair or replace an existing system, or make changes that affect the system.7 For a Mountain View property with onsite wastewater treatment, ask Environmental Health Services about the existing system and the proposed work before designing an addition or ADU.7 We could not confirm Mountain View’s public water and sewer connection requirements or whether off-grid sanitation would be accepted; take those questions to the town’s Building Department before relying on an onsite system.1

Can you live in an RV or tiny home in the Town of Mountain View?

Mountain View prohibits RVs, travel trailers, mobile homes, manufactured housing, industrialized housing and other wheeled or transportable structures from being used as accessory dwelling units.3 That restriction specifically addresses ADUs; we could not confirm the general rule for living in an RV on a Mountain View lot, including during construction.3 We also could not confirm a general tiny-home occupancy rule; ask Mountain View Planning and Zoning about the exact structure and intended use.5 A proposed small ADU must meet Mountain View’s ADU size and parcel requirements, rather than relying on a generic tiny-home label.3

What are the steps to building a home in the Town of Mountain View?

  1. Ask Mountain View Planning and Zoning to review the parcel, proposed use and building placement; the town offers free Design Review Committee meetings for project planning.5
  2. Ask the Mountain View Building Department what building permit documents your project needs, then submit the application and plans through CommunityCore.1
  3. If the property uses septic, discuss changes affecting the system with Jefferson County Public Health.7
  4. Arrange the inspections required for the building work through the town’s Building Department; the inspection line is (303) 450-8748.1

For land outside town limits, consult the Jefferson County guide: the county’s building-code authority applies to designated unincorporated areas rather than incorporated towns.8

Watch-outs

  • Mountain View’s ADU minimum of 220 square feet is an ADU rule, not a confirmed minimum for every kind of dwelling.6
  • We could not confirm Mountain View’s certificate-of-occupancy requirements, private-well rules or floodplain-development procedure; ask the town’s Building Department which approvals your parcel needs before buying or starting work.1

Sources

  1. Town of Mountain View Building Department (SAFEbuilt) (tomv.org)
  2. Septic Systems, quoted and re-checked
  3. 16.14.030 Use standards (Town of Mountain View), quoted and re-checked
  4. Chapter 16 Zoning (Town of Mountain View), quoted and re-checked
  5. Town of Mountain View Planning and Zoning (SAFEbuilt) (tomv.org)
  6. mountainview.municipal.codes (Town of Mountain View), quoted and re-checked
  7. Jefferson County Public Health — Environmental Health Services (jeffco.us)
  8. Colorado Revised Statutes 2025 Title 30 Government - County (Colorado statewide rule), quoted and re-checked

Written October 12, 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.

Answers from the rulebook for Town of Mountain View

Town of Mountain View’s own rules

  • Zoning districtsPublished

    Zoning districts inside Mountain View town.

    • The opened chapter identifies R-2, R-3, C-1, and Planned Development zone districts; numeric district standards were not accessible.
    “Residential-2 (R-2) Zone District [...] Residential-3 (R-3) Zone District”
  • Minimum dwelling sizeSpecified

    Accessory dwelling units inside Mountain View town.

    • This numeric minimum applies to accessory dwelling units, not necessarily every dwelling type.

    minimum ADU living space: >= 220 square feet (Bathrooms and closets are not included.)

    “The minimum size [...] is two hundred twenty (220) square feet”
  • Accessory dwellingsAllowed (with conditions)

    One accessory dwelling unit on a residential parcel inside Mountain View town where a single-family dwelling exists.

    • The ADU may be attached, within an existing structure, or detached.
    • It is subject to adopted building codes.
    • It may not be sold separately or subdivided from the principal dwelling or parcel.
    • The parcel must be at least 6,000 square feet.
    • One ADU is permitted per residential parcel.
    • Maximum size is the lesser of 50% of the principal dwelling's square footage or 650 square feet.
    • Minimum ADU size is 220 square feet of living space, excluding bathrooms and closets.
    • Mobile homes, manufactured housing, industrialized housing, recreational vehicles, travel trailers, and other wheeled or transportable structures may not be used as ADUs.

    minimum parcel size: >= 6000 square feet · maximum ADU size: <= 650 square feet (Also limited to 50% of the principal dwelling's square footage, whichever is less.) · minimum ADU size: >= 220 square feet (Living space; bathrooms and closets excluded.)

    “Accessory dwelling units may be [...] built as a separate, detached structure”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission; ask Town of Mountain View or Jefferson County directly.

  • Owner-builder exemption — Owner-builders inside Mountain View town.
  • Inspections — Building inspections inside Mountain View town.
  • Certificate of occupancy — Certificates of occupancy inside Mountain View town.
  • Minimum lot size — Minimum lot size by zoning district inside Mountain View town.
  • Setbacks — Zoning setbacks inside Mountain View town.
14 more unanswered
  • Lot coverage
  • Building height
  • Living in an RV
  • Tiny homes
  • Manufactured homes
  • Off-grid sanitation
  • Well permit
  • Mandatory utility hookup
  • Agricultural exemption
  • Driveway access
  • Building in a floodplain
  • Short-term rentals
  • Permit fees
  • Permit process

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.

Unanswered questions are usually a sign that Town of Mountain View publishes no rule on the point, not that none exists. Jefferson County’s page lists the county offices to call.

← All of Jefferson County: county rules, score and offices