Ada County, Idaho
We Buy Property in Ada County, Idaho
We buy property across Ada County — houses, land, rentals, multifamily, office and industrial buildings, and parcels with problems attached. Six incorporated cities sit inside the county, plus an unincorporated balance of roughly 64,000 people, and which side of a city limit a property falls on changes who you deal with about almost everything.
That distinction is the single most useful thing to understand before you sell here, and most of what is written about selling in Ada County gets it wrong.
535,799
Residents
Census Bureau, Population Estimates Vintage 2024
6
Incorporated cities
plus unincorporated county — Census place file
27
Irrigation entities
Ada County irrigation districts map
Most property administration here is county-wide
The Ada County Assessor values every non-exempt property in the county at market value as of January 1, whether it sits in Boise, Meridian or open ground outside any city. The same office maintains parcel boundaries, road rights-of-way and Records of Survey, and it runs addressing for every parcel in the county.
The Treasurer, separately, is the ex officio tax collector — collecting for every taxing district including the cities and schools. So the office that decides what a property is worth is not the office that takes payment for it, and a delinquency question goes to the Treasurer rather than the Assessor.
Deeds are recorded with the Ada County Recorder regardless of city. Recorded documents are open to public inspection under Idaho Code 31-2419, and redacting personal information before recording is the responsibility of whoever submits the document — not the Recorder's office.
Land use is not county-wide, and that catches people out
Ada County Development Services processes land use applications in unincorporated Ada County only. Its engineering division handles preliminary plats, drainage, private roads, hillside applications, floodplain permits and boundary adjustments — again, unincorporated only. Inside Boise, Meridian, Eagle, Kuna, Star or Garden City, the city administers its own code.
Code enforcement follows the same line. Ada County states plainly that it does not enforce code violations within city limits and directs city residents to their municipal agency. Complaints in the unincorporated county are investigated by a code enforcement specialist, and the complaining party stays anonymous.
So advice to "contact Ada County about permits" is wrong for the great majority of county residents. It is right for the roughly 64,000 people outside any city, and wrong for everyone else.
Roads and septic answer to neither the city nor the county
Idaho Code 40-1406 bars a city inside a countywide highway district from maintaining city highways or levying property taxes for their construction, repair or maintenance. A single countywide district is responsible for the design, construction and maintenance of city rights-of-way and their curbs, gutters, sidewalks and retaining walls. Ada County confirms it controls no roadway infrastructure of its own.
That has a practical consequence for sellers: a question about a sidewalk, a driveway approach or the road frontage of a parcel in Ada County is a highway district matter, not a city public works matter.
There is no second highway district to check. Idaho law permits only one countywide highway district to operate within a county whose electorate has voted to form one, so the question of which road authority governs a given Ada County parcel has exactly one answer, everywhere in the county. That is unusual enough that people arriving from other states look for a city equivalent that does not exist here.
Septic is different again. Central District Health — a public health district covering Ada, Boise, Elmore and Valley counties — permits septic systems and verifies shallow injection wells. It is not a city building department and not a county one.
The county's cities are not growing at the same rate
Between the 2020 census base and the 2024 Census population estimate, Star grew 61.4% and Kuna 21.0%, while Boise grew 1.0%. Those are not variations on a trend; they are different property markets inside one county.
COMPASS projections reverse parts of that picture by 2050 — Kuna is projected to grow a further 128.7% while Star is projected to add 12.3%, and unincorporated Ada County is projected to lose 36% of its population on the assumption that cities annex the areas they already plan for.
Two estimates of Ada County's population circulate and both are legitimate: COMPASS puts 2024 at 557,590, the Census Bureau's Vintage 2024 estimates put it at 535,799. They are different bodies measuring the same year, and anyone quoting one without naming it is inviting confusion.
We use the Census figure of 535,799 where a single number is needed, and name it as an estimate rather than a count. The two sources differ by about 4%, which is small enough to ignore in conversation and large enough to matter if someone is building an argument on it.
Areas of City Impact
Idaho uses a planning device with no California equivalent: the Area of City Impact, unincorporated land planned jointly with the city it adjoins. Of the people living in unincorporated Ada County, 78.8% live inside one. Only about 13,467 people — 2.4% of the county — live outside any ACI, many of them in the planned communities of Avimor, Cartwright Ranch, Dry Creek Ranch and Hidden Springs.
Property inside an ACI is on county jurisdiction today and is a likely annexation target tomorrow. Boise's ACI holds 284,860 people against a city population of 250,060, which is the clearest illustration of the gap between where a city governs and where it plans.
Irrigation is a live question on a great many parcels
Ada County's own map identifies 27 separate irrigation entities operating in the county — irrigation districts, ditch companies, lateral associations, water companies and a drainage district. Settlers Irrigation District alone delivers to 13,187 acres across West Boise, Meridian and South Eagle. Boise-Kuna and Nampa & Meridian are separate districts serving different ground.
Title to the Boise Project's transferred works — Diversion Dam, the New York Canal, roughly 1,500 miles of canals and laterals — remains with the United States. A canal or lateral crossing a parcel here can therefore sit on federally titled works, which changes who a landowner deals with about access and encroachment.
What the assessed value is, and what it is not
The Assessor's own guidance is unusually direct about this: the assessor does not set a value for a property, but estimates what a typical buyer would reasonably pay for it on January 1. An assessment is an opinion of market value on a fixed date, not a price and not a ceiling.
It is also not the product of a fresh inspection every year. State law requires a physical inspection every five years, so roughly 20% of Ada County properties are reappraised in a given year and the rest are trended on market conditions. A property that has changed materially since its last inspection may be carrying a value derived from a trend rather than from anyone looking at it.
Which appraiser handles a property depends on what it is. Ada County's residential appraisers value detached single-family dwellings, attached townhomes, condominium units, multi-family residential up to four units, and manufactured housing. Apartments and higher-density residential go to commercial appraisers instead — the same four-unit line that separates residential from commercial in lending and in this county's own staffing.
The homeowner's exemption turns on a single day in December
To qualify for the homeowner's exemption for a tax year, an owner must own and occupy the home on or before the last county business day in December, and must file the application by the close of business on that same day. Both conditions land on one date, and the filing is not a formality that can follow later.
Once approved it carries forward. An owner only needs to reapply on a move or on a change of ownership — which is precisely what a sale is. If you are buying or selling here, the exemption does not travel with the property by itself.
A converted manufactured home has stopped being movable property
Idaho requires manufactured homes to be assessed as other residential housing, with those assessments entered on the property roll. That is the assessment side of a conversion. The ownership side is stricter than most people expect.
Once an Idaho manufactured home has been converted to real property it is deemed a fixture and an improvement to the land, and physical removal is prohibited without the consent of every person or entity holding an interest in the real property or title to any estate in it. The homeowner has to obtain a title report from a title insurance company to establish whose consent that means. Owners of rights-of-way, easements and subsurface rights are excluded from the requirement.
There is a notice period as well: at least thirty days' written notice to the county assessor before removal, and the assessor must require written evidence that the necessary consents have been obtained. So a converted home is not something an owner can decide to relocate on their own timetable, and that constraint sits on the property rather than on the person.
When an estate has nobody to administer it
The Ada County Treasurer serves as ex officio public administrator as well as ex officio tax collector, responsible for administering the estates of decedents who have no one to administer the estate.
That is a narrow office and it is rarely the right answer for a family that simply has not started probate yet. But it exists, it is county-level, and it means an Ada County property whose owner has died without anyone stepping forward is not in a legal vacuum — there is a named office with a statutory role.
The flood maps in force here were adopted in 2020
Ada County adopted new FEMA Flood Insurance Rate Maps in June 2020. A parcel's flood status is therefore governed by maps that are recent enough to differ from whatever a prior owner, an older survey or an out-of-date listing described.
This matters most on the properties where it is least expected — ground near the Boise River and its side channels, and parcels crossed by the canal and lateral network described above. Whether a specific parcel is in or out of a mapped zone is a question for the current effective map, not for institutional memory.
Selling with a tenant in place
One narrow but useful fact about the local machinery: the Ada County Court Assistance Office publishes eviction forms, and those forms may be used only to evict a tenant who has not paid rent. They cannot be used to evict a tenant who is current on rent, to sue for back rent, or to move a mobile home from a rented space.
That is a statement about the forms, not about the limits of Idaho landlord-tenant law. It is worth knowing because an owner who assumes the self-service route covers every situation can lose weeks discovering it does not. An occupied sale is usually the simpler path anyway, since a tenancy survives a change of ownership and the deposit obligation transfers with it.
Where the parcel record actually lives
The Assessor maintains comprehensive records on all real and personal property in the county — parcel ownership, land and improvement characteristics, parcel boundaries and road rights-of-way — and manages the addressing process for every parcel. Its online maps carry parcel boundaries, streets, hydrography, section boundaries, city limits, parks and schools, alongside Records of Survey and subdivision plats.
For most questions a seller has about what they actually own, that is the first place to look, and it is county-wide regardless of which city a property sits in. City limits are a layer on the county's map rather than a separate mapping system.
Permits are the opposite. Ada County's building division reviews plans and inspects buildings, and its permitting division accepts building, manufactured home and mechanical permit applications through an online portal — for the unincorporated county. Cities inside a countywide highway district do retain a few defined powers of their own: responsibility for local improvement district bonds issued before the city highway system was dissolved, the ability to spend city funds on trees, shrubs, grass and other plants in rights-of-way, and control of parking meters. Beyond that short list, the road is the highway district's.
Elsewhere in Ada County
Where this comes from
Every factual statement above is traced to a published source, quoted below in the source's own words. Statutes and county practice change; each entry carries the date we last checked it.
Real & Manufactured Property Assessment — Ada County Assessor
Ada County Assessor
Idaho law requires all non-exempt property to be assessed at market value as of January 1, and January 1 is also the lien date for real property.
“Idaho law requires that all non-exempt property be assessed at market value as of January 1st.”
Checked 2026-09-09 · Ada County, Idaho
The Ada County Assessor estimates what a typical buyer would reasonably pay for a property as of January 1 rather than setting its value.
“Remember: The assessor does not set a value for your property. He or she just estimates what a typical buyer would reasonably pay for it on January 1st.”
Checked 2026-09-09 · Ada County, Idaho
All Ada County property is assessed every year, but state law requires a physical inspection every five years; roughly 20% of county properties are reappraised in a given year and the rest are trended on market conditions.
“State law requires properties to be physically inspected every 5 years. Roughly 20% of the properties within the county are reappraised in any given year. During the other four years of the cycle, values are trended based on market conditions.”
Checked 2026-09-09 · Ada County, Idaho
Ada County's residential appraisers value detached single-family dwellings, attached townhomes, condominium units, multi-family residential up to four units, and manufactured housing; apartments and higher-density residential are handled by commercial appraisers.
“Ada County's residential appraisers manage the valuation of all residential property types, including detached single-family dwellings, attached townhomes, condominium units, multi-family residential up to four-units, and manufactured housing.”
Checked 2026-09-09 · Ada County, Idaho
Treasurer — Ada County
Ada County
The Ada County Treasurer serves as ex officio tax collector, responsible for collecting the property taxes levied by all taxing districts including cities and schools.
“The Treasurer serves as ex officio tax collector, responsible for the collection of property taxes levied by the taxing districts, including cities and schools.”
Checked 2026-09-09 · Ada County, Idaho
The Ada County Treasurer also serves as ex officio public administrator, responsible for administering the estates of decedents who have no one to administer the estate.
“The Treasurer also serves as ex officio public administrator, responsible for administering the estates of decedents without a person to administer the estate.”
Checked 2026-09-09 · Ada County, Idaho
Property Records — Ada County Clerk/Recorder
Ada County
The Ada County Recorder's Office maintains all documents related to property ownership within the county, and under Idaho Code 31-2419 all recorded documents are open to public inspection and available for purchase online.
“The Ada County Recorder's Office maintains all documents related to property ownership within the County. ... Pursuant to Idaho Code § 31-2419, all recorded documents are open for public inspection and available for purchase online.”
Checked 2026-09-09 · Ada County, Idaho
When recording a document in Ada County, redacting personal identifying information is the responsibility of the party submitting it, not the Recorder's office.
“If you are submitting documents for recording, it is the responsibility of the party submitting to redact any personal identifying information (PII), such as social security number, date of birth and any account numbers. This is not the responsibility of the Recorder's office to identify and redact personal identifying information (PII).”
Checked 2026-09-09 · Ada County, Idaho
Development Services — Ada County
Ada County Development Services
Ada County's planning division processes land use applications only in unincorporated Ada County; land use inside an incorporated city is that city's jurisdiction.
“Our planning division processes land use applications in unincorporated Ada County and works with the Ada County Historic Preservation Council...”
Checked 2026-09-09 · Ada County, Idaho
Ada County's engineering and surveying division reviews preliminary plats, drainage plans, private roads, hillside applications, floodplain permits and property boundary adjustments in unincorporated Ada County.
“Our engineering and surveying division reviews preliminary plats, drainage plans, private roads, hillside applications, floodplain permits, and property boundary adjustments in unincorporated Ada County.”
Checked 2026-09-09 · Ada County, Idaho
Ada County's building division reviews plans and inspects buildings, and its permitting division accepts building, manufactured home and mechanical permit applications through a client portal.
“Our building division reviews plans and inspects buildings to ensure Ada County residents are safe in any building they walk into.”
Checked 2026-09-09 · Ada County, Idaho
Code Enforcement — Ada County Sheriff
Ada County Sheriff
Ada County Code Enforcement investigates land use and building code complaints in unincorporated Ada County only, and expressly does not enforce code violations within city limits; complainants remain anonymous.
“Ada County Code Enforcement does not enforce code violations within city limits. Please contact the municipal agency directly. ... A Code Enforcement Specialist will investigate written and verbal complaints concerning land use and building code issues in unincorporated Ada County. ... The complaining party will remain anonymous.”
Checked 2026-09-09 · Ada County, Idaho
Idaho Code § 40-1406 — Powers and duties of highway commissioners — One highway district in county — Highway powers of cities in county abolished — Laws in conflict superseded
Idaho State Legislature
Amendment history
[40-1406, added 1985, ch. 253, sec. 2, p. 659; am. 1988, ch. 298, sec. 1, p. 942; am. 2023, ch. 306, sec. 1, p. 920.]
A city inside a countywide highway district may not maintain or supervise city highways, and may not levy ad valorem taxes for their construction, repair or maintenance.
“No city included within a county-wide highway district shall maintain or supervise any city highways or levy any ad valorem taxes for the construction, repair or maintenance of city highways.”
Checked 2026-09-09 · Idaho
Idaho law permits only one countywide highway district to operate within a county that has voted to form one.
“Only one (1) county-wide highway district shall be operative within a county where the electorate has voted affirmatively for the formation of a county-wide highway district.”
Checked 2026-09-09 · Idaho
Idaho Code § 40-1415 — Responsibilities of single countywide highway districts within cities
Idaho State Legislature
Amendment history
[40-1415, added 1985, ch. 253, sec. 2, p. 662; am. 2021, ch. 273, sec. 1, p. 824.]
A single countywide highway district is responsible for design, construction, reconstruction and maintenance of city rights-of-way and their curbs, gutters, culverts, sidewalks, paved medians, bulkheads and retaining walls.
“shall be responsible for the design, construction, reconstruction and maintenance of city rights-of-way and accompanying curbs, gutters, culverts, sidewalks, paved medians, bulkheads and retaining walls”
Checked 2026-09-09 · Idaho
Cities within a countywide highway district retain responsibility for pre-existing local improvement district bonds, may spend city funds on trees, shrubs, grass and other plants in rights-of-way, and control parking meters.
“jurisdiction and responsibility for outstanding local improvement district bonds or warrants sold or issued by the city prior to dissolution of the city highway system”
Checked 2026-09-09 · Idaho
Transportation — Ada County Development Services, Community Planning Division
Ada County Development Services
Ada County Development Services controls no roadway infrastructure within the county's boundaries; the Ada County Highway District leads identification and development of transportation projects and maintains the county's Master Street Map.
“While Ada County Development Services does not control any roadway infrastructure within its boundaries, these plans help us to be better partners with partner agencies and our residents.”
Checked 2026-09-09 · Ada County, Idaho
Water, Wastewater & Septic — Central District Health
Central District Health
Central District Health's Environmental Health Division permits septic systems, reviews land development applications and verifies the location of shallow injection wells across Ada, Boise, Elmore and Valley counties.
“Environmental Health Specialists at Central District Health (CDH) permit septic systems, review land development applications and verify location of shallow injection wells to ensure reliable and safe water resources for the community.”
Checked 2026-09-09 · Ada County, Idaho
Population Estimates, Vintage 2024 — Subcounty Resident Population
U.S. Census Bureau
Population growth across Ada County's cities diverged sharply between the 2020 census base and the 2024 estimate: Star +61.4%, Kuna +21.0%, Meridian +18.6%, Eagle +7.4%, Garden City +5.1%, Boise +1.0%.
Checked 2026-09-09 · Ada County, Idaho
Comprehensive Population Demographics — Ada County
Ada County
COMPASS projects Ada County will reach 715,820 by 2050, but the growth is projected to be very unevenly distributed: Kuna +128.7%, Eagle +50.6%, Garden City +42.0%, Meridian +34.8%, Boise +25.8%, Star +12.3%, while unincorporated Ada County is projected to LOSE 36.0% of its population.
“Unincorporated Ada County is projected to see a decrease of 22,920 residents by 2050, based on the assumption the cities will have annexed all of the area within their current ACI boundaries by that time.”
Checked 2026-09-09 · Ada County, Idaho
Two authoritative estimates of Ada County's 2024 population coexist and differ by about 4%: COMPASS puts it at 557,590; the U.S. Census Bureau's Population Estimates, Vintage 2024, puts it at 535,799.
“According to COMPASS estimates, Ada County's population reached 557,590 in 2024, with the majority (88.6%) living in one of the County's six cities.”
Checked 2026-09-09 · Ada County, Idaho
Ada County uses Areas of City Impact — unincorporated land planned in conjunction with an adjacent city. 78.8% of unincorporated Ada County residents (about 50,143 people) live inside an ACI, and only about 13,467 people, 2.4% of the county, live outside any ACI.
“Of those living in unincorporated Ada County, 78.8% (50,143) are estimated to live within an Area of City Impact (ACI). Only approximately 13,467 people live in unincorporated areas of the County outside of ACIs”
Checked 2026-09-09 · Ada County, Idaho
Most Ada County residents living outside any Area of City Impact are in the planned communities of Avimor, Cartwright Ranch, Dry Creek Ranch and Hidden Springs.
“with many of these residents living in the planned communities of Avimor, Cartwright Ranch, Dry Creek Ranch and Hidden Springs.”
Checked 2026-09-09 · Ada County, Idaho
Population Estimates, Vintage 2024 — County Resident Population
U.S. Census Bureau
Ada County's estimated resident population was 535,799 in 2024.
Checked 2026-09-09 · Ada County, Idaho
Irrigation Districts Map — Ada County Development Services
Ada County Development Services
Ada County's own irrigation districts map identifies 27 separate irrigation entities operating in the county — irrigation districts, ditch companies, lateral associations, water companies and a drainage district — plus the Boise Project Board of Control as operating agent.
Checked 2026-09-09 · Ada County, Idaho
About — Settlers Irrigation District
Settlers Irrigation District
Settlers Irrigation District delivers irrigation water to 13,187 acres of agricultural and urban land in western Ada County — the West Boise, Meridian and South Eagle areas — via a 20-mile canal and 95 miles of laterals.
“Settlers Irrigation District continues to deliver irrigation water to 13,187 acres of both agricultural and urban lands located in West Boise, Meridian, and South Eagle areas.”
Checked 2026-09-09 · Ada County, Idaho
About — Boise Project Board of Control
Boise Project Board of Control
Title to the Boise Project's transferred works — including Diversion Dam, the New York Canal, the Lake Lowell embankments and roughly 1,500 miles of canals, laterals and drains — remains in the United States.
“These facilities are referred to as "transferred works" and include all of the facilities beginning at Diversion Dam on the Boise River, and including the New York Canal, the embankments at Lake Lowell and approximately 1500 miles of canals, laterals, and drains. Title to the "transferred works" remains in the United States.”
Checked 2026-09-09 · Idaho
Homeowner's Tax Relief — Ada County Assessor
Ada County Assessor
To qualify for the homeowner's exemption for a tax year, an owner must own and occupy the home on or before the last county business day in December and file the application by close of business that same day; once approved it need only be re-filed on a move or a change of ownership.
“To qualify, you must own and occupy your home on or before the last county business day in December. You must also submit an application to our office by the close of business on that same day for the current tax year. Once approved, you only need to reapply if you move or if ownership of the property changes.”
Checked 2026-09-09 · Ada County, Idaho
Idaho Code § 63-303 — Assessment of manufactured homes
Idaho State Legislature
Idaho requires manufactured homes to be assessed as other residential housing, with those assessments entered on the property roll.
“Manufactured homes shall be assessed as other residential housing and such assessments shall be entered on the property roll.”
Checked 2026-09-10 · Idaho
Idaho Code § 63-305 — Reversal of declaration which treats a manufactured home as real property
Idaho State Legislature
Once an Idaho manufactured home has been converted to real property, it is deemed a fixture and an improvement to the land, and physically removing it is prohibited without the consent of every person or entity holding an interest in the real property or title to any estate in it. The homeowner must obtain a title report from a title insurance company to establish whose consent is required. Owners of rights-of-way, easements and subsurface rights are excluded from that requirement.
“Physical removal shall be prohibited without the consent of all persons or entities who, at the time of removal have an interest in the real property or title to any estate in the real property to which the manufactured home has been affixed.”
Checked 2026-09-10 · Idaho
An Idaho homeowner must give the county assessor at least thirty days' written notice before removing a manufactured home that has been converted to real property, and the assessor must require written evidence that the necessary consents have been obtained.
“At least thirty (30) days before the manufactured home is to be removed, the homeowner shall give written notice of the intended removal to the county assessor in the county in which the real property is located.”
Checked 2026-09-10 · Idaho
Hazardous Overlay Districts — Ada County Development Services
Ada County Development Services
Ada County adopted new FEMA Flood Insurance Rate Maps in June 2020.
“In June, 2020, Ada County adopted the new FEMA Flood Insurance Rate Maps.”
Checked 2026-09-09 · Ada County, Idaho
Landlord Tenant — Ada County Court Assistance
Ada County
The Ada County Court Assistance Office's eviction forms may be used only to evict a tenant who has not paid rent; they cannot be used to evict a tenant current on rent, to sue for back rent, or to move a mobile home from a rented space.
“Eviction forms on our site can only be used to evict a tenant who has not paid rent. You cannot use our forms to evict a tenant who is up to date on their rent, sue for back rent or move a mobile home from a rented space.”
Checked 2026-09-09 · Ada County, Idaho
Assessor's Property Records — Ada County Assessor
Ada County Assessor
The Ada County Assessor maintains comprehensive property records on all real and personal property in the county — parcel ownership, land and improvement characteristics, parcel boundaries and road rights-of-way — and manages the addressing process for all parcels in the county. Its online maps carry parcel boundaries, streets, hydrography, section boundaries, city limits, parks and schools, alongside Records of Survey and subdivision plats.
“The Ada County Assessor's Office maintains comprehensive property records on all real and personal property within the county. This includes, parcel ownership, land and improvement characteristics, parcel boundaries, road rights-of-way, and the office also manages the addressing processes for all parcels within the county.”
Checked 2026-09-09 · Ada County, Idaho
Start with the address.
One field. We will look at the parcel and the comparable sales, then come back with a number and the working behind it. No obligation, and no pressure if the answer is that you should list it instead.
Serving Boise, Meridian, Eagle, Kuna, Star, Garden City and unincorporated Ada County.