Boise multifamily investment guide

Across this series we have found four different ways a state controls property tax. Indiana caps the tax as a share of your value and writes it into its constitution. Nevada caps your annual increase and conditions the cap on the rent you charge. Michigan caps your assessment and uncaps it the moment you buy. Ohio rolls back the millage so an existing levy keeps yielding the same dollars. Idaho does a fifth thing, and it is the one that moves burden between owners rather than limiting it.

Idaho caps the budget. Section 63-802 of the Idaho Code limits a taxing district to "the highest dollar amount of property taxes certified for its annual budget for any one (1) of the three (3) tax years preceding the current tax year, which amount may be increased by a growth factor of not to exceed three percent (3%)," plus revenue attributable to new construction and annexation, subject to a general ceiling of "eight percent (8%)" on the total increase, with fire protection and ambulance districts allowed more.

Note what that does and does not do. It does not cap your rate. It does not cap your assessment. It fixes the total number of dollars the district may raise. The levy rate is then whatever it needs to be to raise that amount from the taxable base, which means the rate falls when values rise. Your own bill goes up only to the extent your property appreciates faster than the district average.

Now the second provision, and this is where it becomes a multifamily question. Section 63-602G exempts from taxation "the first one hundred twenty-five thousand dollars ($125,000) of the market value for assessment purposes of the homestead ... or fifty percent (50%) of the market value ... whichever is the lesser." The condition is that "[t]he homestead is owner-occupied and used as the primary dwelling place of the owner." A rental property does not qualify.²

Put the two together. The amount to be collected is fixed by statute. Half the value of every owner-occupied home, up to $125,000, is removed from the base that has to produce it. Everything that remains in the base, which includes every rental unit, every commercial building and every second home, carries a proportionally larger share of the same fixed total.²

In Ada County that matters because of who owns. 70.8 percent of households are owner-occupied, so the exemption reaches the large majority of the housing stock, and the 29.2 percent that rents sits on the non-exempt side of the ledger along with commercial property.²

This is a different shape of risk from the one in Alabama, where converting an owner-occupied house to a rental doubles its assessment ratio, though it produces a related outcome. Alabama changes what your property is worth for tax purposes. Idaho changes what share of a fixed bill your property is asked to pay. Both fall on the landlord, and neither shows up if you model a flat effective rate against value.

• A district may grow its budget by three percent plus new construction, capped at eight percent overall.
• The rate is whatever raises that fixed amount, so rates fall as values rise.
• Owner-occupied homes are exempt on the lesser of half their value or $125,000.²
• Rentals do not qualify, so they carry more of a fixed total.

Idaho does not limit what you pay. It fixes what the district collects, then lifts half of most homes out of the base. Your share of a fixed number is the thing to model.

The demand and supply picture here is strong on one side and genuinely constrained on the other, and the constraint is not the one investors usually worry about.

Ada County reached 546,141 people as of July 2025, up 10.3 percent from its April 2020 base. That is among the strongest growth in our coverage, though below Hamilton County, Indiana at 11.4 percent. Incomes are high and poverty is low: median household income of $91,502 and a poverty rate of 8.9 percent, with 44.6 percent of adults holding a bachelor’s degree or higher.²

Housing is expensive against those incomes. Median home value is $512,300, about 5.6 times median household income on our arithmetic, essentially the same multiple as Clark County, Nevada and above Salt Lake County at 5.4.²

The constraint is the renter pool. Only 29.2 percent of Ada County households rent, one of the smaller shares in our coverage, though Hamilton County, Indiana at 23.9 percent and Waukesha County at 24.0 are smaller still. A market can have excellent demographics and still be a difficult place to own apartments if most households buy instead.²

And supply is arriving. 5,221 permits against 228,926 units is about 2.28 percent of stock, and construction employment grew 3.8 percent to 40,900, which is about 9.7 percent of all metro employment on our arithmetic. The builders are busy, and they are building into a county where seven households in ten already own.¹²

Rent is comfortable against income at $1,577, absorbing about 20.7 percent of median household income, and owning costs $1,905, a difference of $328. That narrow gap is the same pattern we have flagged repeatedly: it makes the renter base discretionary and rate-sensitive.²

Employment is healthy and broad. Total nonfarm reached 420,000 in July 2026, up 1.0 percent, with unemployment at 3.3 percent, down from 3.5. Eight of the ten reported sectors grew. Only leisure and hospitality, down 1.9 percent, and information, down 6.5 percent on a base of 4,300, declined.¹

• Population up 10.3 percent, median household income $91,502, poverty 8.9 percent.²
• Homes cost about 5.6 times median income.²
• Only 29.2 percent of households rent.²
• Permits at 2.28 percent of stock and construction employment up 3.8 percent.¹²

Excellent demographics do not make an apartment market. Seven households in ten here already own, and the builders are still busy.