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.
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.
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.
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
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
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
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
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'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
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
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 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
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
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
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
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
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 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
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
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
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
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
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.