Franklin County, ID Building Permits & Zoning

Franklin County, Idaho requires a building permit for a home, and the county has adopted building codes and land-use zoning¹²³. Agricultural buildings have a code exemption, but they still must meet zoning placement rules⁴. Southeastern Idaho Public Health handles onsite septic permits, and the septic permit must come before the county building permit⁵⁶.

At a glance

Building permit: Required for a home¹
Building codes: Adopted by Franklin County²
Zoning: Yes; confirm parcel-specific rules with Planning & Zoning³
Septic permits: Southeastern Idaho Public Health⁵
Agricultural buildings: Exempt from adopted building codes, but zoning placement still applies⁴
Owner-builder exemption: We could not confirm one⁷
Septic soil suitability: 5.3% of soils avoid a severe conventional drain-field limitation⁸
Property taxes: 0.5% effective rate; $1,512 median annual bill⁹¹⁰

Who to call

Building permits

Franklin County Building Department

Building permits and inspections for Franklin County; the county page says the septic permit must be completed before a building permit can be issued

208-221-6149

[email protected]

561 West Oneida

Zoning

Franklin County Planning & Zoning

Planning, zoning, development-code materials, subdivisions and agricultural building-exemption materials

208-220-2120

[email protected]

Septic permits

Southeastern Idaho Public Health — Franklin County Office

Local contact for the public health district that administers onsite septic permitting in Franklin County

(208) 852-0478

42 West 1st South, Preston, Idaho 83263

Roads & driveways

Franklin County Road and Bridge

County right-of-way and approach permit materials

208-852-0610

[email protected]

561 West Oneida Preston, ID 83263

Contact details are copied from each office’s official page and were checked against it on September 27, 2026.

Do you need a building permit in Franklin County, Idaho?

Yes. Franklin County requires a building permit for a home, and the county has adopted official building codes¹². Idaho also requires permits whenever electrical, plumbing or HVAC work is performed, although a local jurisdiction may administer some of those programs¹¹. Agricultural buildings are the important exception: Franklin County exempts them from its adopted building codes, but zoning placement requirements still apply⁴. Do not treat that agricultural exemption as a general exemption for a farmhouse, cabin or other residence. The county's Building Department publishes the building-permit materials and tells applicants to send permits to that department⁶.

Who is the Franklin County building department, and how do you reach it?

Franklin County's Building Department is at 561 West Oneida in Preston; call 208-221-6149 or email [email protected]⁶. The department publishes building, mechanical and agricultural permit materials, along with a residential builders handbook and design criteria⁶. For land-use questions, contact Franklin County Planning & Zoning at 208-220-2120 or [email protected] at the same West Oneida location¹². The county's general building-permit thresholds, inspection sequence, certificate-of-occupancy process and complete fee schedule could not be confirmed from the reviewed material. Ask the Building Department for the current application packet, fee total and required inspections before budgeting or scheduling construction.

Does Franklin County have zoning?

Yes. Franklin County administers zoning and publishes an amended development code, but the reviewed material does not settle every district boundary or parcel-level standard³¹². That means a listing described as rural or agricultural is not enough to establish what you may build. Ask Planning & Zoning to identify the parcel's district and confirm its permitted uses, setbacks, minimum lot size, building height and any subdivision or area-of-impact rules. The county publishes a subdivision application and agricultural building-exemption material through the same office¹². Franklin County's agricultural building-code exemption does not waive zoning placement requirements⁴. Rules inside incorporated cities may differ, so confirm which jurisdiction controls the parcel before relying on county guidance.

How do septic permits work in Franklin County?

Southeastern Idaho Public Health administers onsite septic permitting for Franklin County under Idaho's district system⁵¹³¹⁴. Start with the district's Franklin County office at 42 West 1st South in Preston, phone (208) 852-0478¹⁵. Every application needs an onsite evaluation; the applicant supplies test holes at least 8–10 feet deep depending on soil type, along with a completed application and plot plan, proof of ownership and the fee¹⁶. The published basic or complex system fee is $850, though fees can change¹⁶. Only 5.3% of county soils avoid a severe limitation for a conventional drain field, so make septic feasibility a purchase contingency rather than assuming a standard system will work⁸. A final installation inspection is required before a system receives wastewater¹⁷. The county requires the septic permit before issuing the building permit⁶.

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

Franklin County's rules for long-term RV living, temporary camping on private land and tiny-home occupancy could not be confirmed from the reviewed material. County zoning exists, so do not assume a rural parcel allows residential RV use or a tiny home simply because the land is outside a city³. Ask Planning & Zoning to confirm the parcel's permitted residential use, setbacks, minimum dwelling size and whether temporary occupancy during construction is allowed¹². If the project uses a manufactured home, Idaho requires every installation to be inspected and approved by the state division or the authority having jurisdiction before occupancy¹⁸. A tiny dwelling still needs an approved wastewater plan: the health district administers septic permits in Franklin County⁵.

How do you build a home in Franklin County, step by step?

Ask Franklin County Planning & Zoning to verify the parcel's zoning district, permitted dwelling type and dimensional standards³¹².
Have Southeastern Idaho Public Health evaluate the site and issue the septic permit; Franklin County requires that permit before the building permit¹⁶⁶.
Confirm water. Before drilling a private well, obtain an Idaho Department of Water Resources drilling permit and use a licensed well driller¹⁹.
Apply to the Franklin County Building Department and confirm the current fee, plan requirements and inspection schedule¹⁶.
Obtain separate permits for electrical, plumbing or HVAC work through the applicable Idaho or local program¹¹.
If access crosses county right-of-way, ask Road and Bridge about its approach permit; a connection to state-highway right-of-way requires an Idaho Transportation Department encroachment permit²⁰²¹.
Complete the required septic inspection before putting the system into service¹⁷.

What should you check before buying land in Franklin County?

Make septic feasibility the first physical-site check: only 5.3% of Franklin County soils avoid a severe limitation for a conventional drain field⁸. Confirm zoning and legal access next, including whether the parcel can support the intended dwelling and whether a county approach permit or state-highway encroachment permit is needed³²⁰²¹. For a private well, budget for the required state drilling permit and licensed driller¹⁹. Franklin County is sparsely settled at about 23.4 people per square mile, and 32.9% of its land is federally owned, so nearby public land does not establish private access or development rights²²²³. The effective property-tax rate is about 0.5%, with a median annual property-tax bill of $1,512⁹¹⁰. Before closing, get written parcel-specific answers from Planning & Zoning, the Building Department and the health district.

Watch-outs

A Franklin County agricultural building may be exempt from adopted building codes while still remaining subject to zoning placement requirements⁴.
Franklin County requires the septic permit to be completed before it will issue the building permit⁶.
Long-term RV living, private-land camping, tiny-home occupancy and an owner-builder exemption could not be confirmed; ask Planning & Zoning and the Building Department before relying on any of them⁷¹²⁶.

Sources

Written September 27, 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.

How Franklin County scores

Seclusion54100% ev.

Self-Sufficiency47100% ev.

Admin Boringness3890% ev.

Durability62100% ev.

Property Autonomy90100% ev.

Carry Cost77100% 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 →

$448kTypical home

0.5%Property tax

$3,278Land / acre

23.1"Annual rain

13.5% of yrsSevere drought

2.4 / yr (+2.3)Mid-century 100°F days

26.6 daysMid-century dry spell

1.1" (+7.4%)Mid-century 1-day rain

1.16×Wildfire change factor

100%Forward climate coverage

$1,297Home insurance / yr

4.8% / yrInsurance growth

1.53%Nonrenewal rate

county median (2+ published ZIPs)Insurance basis

32,819People within 30 min

1,971,738People within 2 hr

15,314Radius comparison (15 mi)

23.4People / sq mi

32.9%Federal land

35.2%Land at 15% slope or less

5.3%Septic soil without severe limits

22,085 acWorkable land screen

34.8%Wooded land

21.4 tonsBiomass / forest ac

44.6°FAvg temp

Answers from the rulebook for Franklin County

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

Franklin County rules

Building code adoptedAdopted (with conditions)
Official building codes adopted by Franklin County.
- Agricultural buildings are exempt from the adopted building codes but remain subject to zoning placement requirements.
- The ordinance states that adopted versions are superseded by successive versions adopted or approved by the Idaho Building Code Board effective when those state versions become effective.
“are adopted as the official building codes of the County of Franklin”
Ordinance No. 2003-1: Ordinance Adopting the International Codes ↗Re-checked Sep 25, 2026
Who permits septicLocal (with conditions)
Onsite septic regulation and permitting serving Franklin County through Southeastern Idaho Public Health.
- The district serves multiple counties and operates under Idaho Code and applicable state and district health laws, regulations, and standards.
“The Southeastern Idaho Public Health Board of Health consists of eight voting members, one from each of the counties we serve. [...] Franklin County”
Board of Health ↗Re-checked Sep 25, 2026
Septic permitRequired
Individual and subsurface sewage systems in Franklin County served by Southeastern Idaho Public Health.
- An onsite evaluation is required for all applications.
- The applicant must provide test holes at least 8-10 feet deep depending on soil type.
- The application must include a complete signed and dated application and plot plan, proof of ownership, and applicable fees.
- The governing rules establish requirements for obtaining an installation permit and installer registration permit and apply to every individual and subsurface blackwaste and wastewater treatment system in Idaho.
- Published fees include $850 for a basic or complex sewage disposal permit, $3,000 for a large soil absorption system, $300 for a tank-only permit, $300 for a speculative site evaluation, and $40 for septic permit renewal; fees are subject to change.
basic or complex sewage disposal permit fee: 850 USD · large soil absorption system permit fee: 3000 USD · tank-only permit fee: 300 USD
“INFORMATION REQUIRED TO APPLY FOR A SEPTIC PERMIT”
Septic Permits ↗Re-checked Sep 25, 2026
Agricultural exemptionAvailable (with conditions)
Agricultural buildings subject to Franklin County building codes.
- The exemption applies to agricultural buildings from the building codes adopted by the ordinance.
- Agricultural buildings remain subject to placement requirements established by zoning regulations.
“Agricultural buildings are exempt from the building codes adopted herein”
Ordinance No. 2003-1: Ordinance Adopting the International Codes ↗Re-checked Sep 25, 2026
County-wide zoningPresent
County has an adopted Development Code (amended 2026) and Comprehensive Plan; land is zoned (default agriculture) and must be changed to a building lot.
Franklin County, ID - Planning & Zoning ↗Scouted from the county site, not yet independently re-checked

Idaho rules that apply here

Building permitLimited
New manufactured-home installations in Idaho locations without an approved local building program.
- The installation permit and tag are required only for new homes.
- The requirement applies in areas where there is not an approved local building program.
- The permit must be obtained before starting installation.
“An installation permit and installation tag (required only for new homes) is required by Idaho Division of Occupational and Professional Licenses prior to starting the installation in areas where there is not an approved local building program.”
Building Archives - Division of Occupational and Professional Licenses ↗Re-checked Sep 11, 2026
One more reviewed finding on this topic
- Required — Electrical, plumbing, or HVAC work in Idaho subject to the state-administered permit program.
  “A permit is required when any electrical, plumbing or HVAC work is performed.”
  Frequently Asked Questions (FAQs) - Division of Occupational and Professional Licenses ↗Re-checked Sep 11, 2026
InspectionsRequired
All manufactured-home installations in Idaho before the manufactured home is occupied.
- The inspection and approval are performed by DOPL or the authority having jurisdiction.
- Inspection and approval must occur before occupancy.
“All installations must be inspected and approved by the Idaho Division of Occupational and Professional Licenses or the authority having jurisdiction before the manufactured home is occupied.”
Building Archives - Division of Occupational and Professional Licenses ↗Re-checked Sep 11, 2026
Camping on your landLimited
Camping or parking a vehicle or trailer on Idaho Fish and Game Wildlife Management Areas and access sites separate from a WMA.
- The restriction applies in areas posted against camping or parking.
- Leaving an unattended camp, vehicle, or trailer for more than 48 hours is prohibited without authorization.
- Camping or parking for more than 10 days during any 30-day period on one WMA or one separate access site is prohibited without authorization.
- The rule permits authorization by the Commission, Director, Regional Supervisor, or designee.
unattended duration: > 48 hours (Unless specifically authorized by the Commission, Director, Regional Supervisor, or designee.) · camping or parking duration: > 10 days during any 30-day period per WMA or separate access site (Unless specifically authorized by the Commission, Director, Regional Supervisor, or designee.)
“camp or park a vehicle or trailer for more than ten (10) days during any thirty (30) day period”
Public Use of Department Lands and Access Areas ↗Re-checked Sep 11, 2026
Accessory dwellingsLimited
Accessory dwelling units for Idaho DEQ wastewater-flow and septic-system sizing purposes; this claim does not establish statewide zoning permission.
- An ADU is sized as a single-family dwelling for the cited wastewater-flow guidance.
- An ADU may combine flows with another structure into one system.
- Any common septic tank must be large enough to hold the required capacity from both structures.
- Local land-use, building, and septic authorities may impose additional requirements.
wastewater flow basis: single-family dwelling
“Size as a single family dwelling. Can combine with another structure's flows into one system”
Idaho DEQ - Uncommon Wastewater Flows ↗Re-checked Sep 11, 2026
Septic inspectionRequired
Individual and subsurface sewage disposal systems constructed or installed under Idaho’s onsite wastewater rules.
- The Director requires one or more inspections necessary to determine compliance.
- The permittee must uncover or make available for inspection any portion covered or concealed in violation of the rules.
- If preparation is required, the applicant or permittee must provide at least 48 hours’ advance notice, excluding weekends and holidays.
- For individual systems, the public health district inspects the installation.
- Large soil absorption systems are inspected by the public health district and DEQ.
advance inspection notice: >= 48 hours (Excludes weekends and holidays.)
“No system may receive wastewater until the Director conducts a final installation inspection”
IDAPA 58.01.03 Individual/Subsurface Sewage Disposal Rules ↗Re-checked Sep 11, 2026
Well permitRequired
Construction or drilling of wells in Idaho, including domestic wells.
- Before drilling, the well owner or driller must obtain a drilling permit from IDWR.
- All wells must be constructed by a well driller with a valid IDWR license.
- The separate water-right permit exemption for domestic purposes does not eliminate the drilling-permit requirement.
- For new diversions in qualifying subdivisions filed on or after July 1, 2025, a water-right permit is required in a moratorium area, critical groundwater area, or groundwater management area, except for in-home uses and watering livestock.
- Well construction rules apply to wells and other artificial openings more than 18 vertical feet below land surface.
well depth threshold: > 18 vertical feet below land surface (The cited well-construction rules describe covered wells and artificial openings.) · subdivision application date: >= 2025-07-01 (Applies to qualifying new diversions described in Idaho Code § 42-227(4).)
“Prior to drilling a well, the well owner or well driller must first obtain a drilling permit from IDWR.”
Wells Overview ↗Re-checked Sep 11, 2026
Mandatory utility hookupConditional
Proposed individual or subsurface sewage disposal systems where public or central wastewater treatment facilities may be available.
- The Director may deny a septic permit when public or central wastewater treatment facilities are reasonably accessible.
- The cited rule does not establish a universal statewide requirement to connect every property to public sewer.
- Subsurface septic discharge remains an identified onsite disposal method.
“Public or central wastewater treatment facilities are reasonably accessible.”
IDAPA 58.01.03 Individual/Subsurface Sewage Disposal Rules ↗Re-checked Sep 11, 2026
Driveway accessRequired
Private and public driveways or streets connecting to Idaho state highway right-of-way.
- An ITD encroachment permit is required for private and public approaches, including driveways and streets.
- No activity may occur on state highway rights-of-way until the Department or a delegated local highway agency issues an approved permit, except emergency approval affecting highway operations and motorist safety may precede processing.
- A Traffic Impact Study may be required for new or expanded development seeking direct access to a state highway when the stated thresholds are met, unless waived by the District Engineer.
peak-hour trips for possible TIS requirement: >= 100 new trips (unless waived by the District Engineer) · daily traffic for possible TIS requirement: >= 1000 vehicles per day (unless waived by the District Engineer)
“Encroachment permits approved by the Department are required for private and public approaches (driveways and streets), utilities and other miscellaneous encroachments.”
Types of Right-of-Way Encroachment Permits ↗Re-checked Sep 11, 2026

Still unanswered

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

Owner-builder exemption — Owner-builder exemptions from building requirements in Franklin County.
Certificate of occupancy — Certificates of occupancy in Franklin County.
Local zoning — Aggregate local zoning across Franklin County and incorporated municipalities.
Zoning districts — Published zoning districts in Franklin County.
Minimum dwelling size — Minimum dwelling-size requirements in Franklin County.

12 more unanswered

Minimum lot size
Setbacks
Lot coverage
Building height
Living in an RV
Tiny homes
Manufactured homes
Off-grid sanitation
Subdividing land
Building in a floodplain
Short-term rentals
Permit fees

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 Franklin County

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

Actively managed

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

Household wellExempt — no permit or water right

Groundwater for domestic purposes up to 13,000 gpd is exempt from permitting; critical-area and moratorium closures generally target new PERMITTED (non-exempt) appropriations, so a household can still drill a domestic-exempt well even inside a critical groundwater area.

Limit: 13,000 gpd (homes, stockwater, irrigation of ≤0.5 acre) under Idaho Code 42-227

Idaho Dept of Water Resources — Domestic Exemption ↗

Bear River Ground Water Management Areapartial of county
Designated 2001; new appropriations must demonstrate sufficient supply without injuring senior rights. Domestic-exempt wells allowed.
Idaho Dept of Water Resources — Designated Ground Water Management Areas ↗
Malad Valley Ground Water Management Areapartial of county
Designated 2015; temporary moratorium on new non-exempt appropriations extended through 2027. Domestic-exempt wells allowed.
Idaho Dept of Water Resources — Designated Ground Water Management Areas ↗

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

Living off-grid in Franklin County, Idaho

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

Franklin County scores 64/100 on the Bolthole Index, a strong county profile. Its strengths: a stronger property-autonomy legal backdrop and manageable long-term carry cost. Watch-outs: more administrative friction around building and land use.

Do you need a building permit in Franklin County, Idaho?

Franklin County generally requires a residential building permit, and it enforces county zoning. Onsite septic is permitted by Southeastern Idaho Public Health (SIPH). 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 Franklin County, Idaho?

Land in Franklin County runs about $3,278 per acre, based on the latest county data.

What is the water situation in Franklin County?

Franklin County gets about 23.1" of rain a year, with severe drought in roughly 13.5% of years. On water rights, Franklin County lies in the Bear River Ground Water Management Area — Designated 2001; new appropriations must demonstrate sufficient supply without injuring senior rights. Domestic-exempt wells allowed..

How remote is Franklin County?

A representative private-land location has about 32,819 people within a 30-minute drive and 1,971,738 within two hours. The road-network catchments count population across county lines and clusters of smaller cities; straight-line radius values remain available as a comparison.

Building permits, zoning and land rules in Franklin County, Idaho

At a glance

Who to call

Do you need a building permit in Franklin County, Idaho?

Who is the Franklin County building department, and how do you reach it?

Does Franklin County have zoning?

How do septic permits work in Franklin County?

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

How do you build a home in Franklin County, step by step?

What should you check before buying land in Franklin County?

Watch-outs

Sources

Franklin County in Idaho

How Franklin County scores

Find land. Bring the promising ones back.

Parcel due diligence

Answers from the rulebook for Franklin County

Franklin County rules

Idaho rules that apply here

Still unanswered

Water rights & wells in Franklin County

Living off-grid in Franklin County, Idaho

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

Do you need a building permit in Franklin County, Idaho?

How much does land cost in Franklin County, Idaho?

What is the water situation in Franklin County?

How remote is Franklin County?

How Franklin compares in Idaho