Multifamily
Selling multifamily property, five units and up
Five units and up, priced on rent roll and net operating income rather than on comparable sales. Fourplexes and below we buy as well, and those we handle on the residential side, because that is where the financing and the appraisal method still sit.
This page is about what changes when a building crosses that line, and about a definition that is much less settled than it sounds.
There is no single point where multifamily begins
It is often said that five units is where a property becomes commercial. That is a useful rule of thumb and it is not a legal fact, because there is no one system whose answer governs all the others.
The federal housing-finance definition treats a multifamily property as one with more than four units, which is the boundary most people are reaching for. The Census Bureau's residential construction statistics treat multifamily as buildings with two or more units. Federal housing programmes are not uniform either — different programmes use different unit thresholds for different purposes. Idaho's own statutes add further variations of their own for their own purposes.
Idaho adds one more, from an unexpected direction. The state's architects chapter does not reach architectural services for a building used as a single or multiple family residence not exceeding three units or three stories. The exemption stops at three — so a triplex sits inside it and a fourplex does not.
Seven systems, and no two of them agree. The lines fall at two, three, four and five depending on who is asking. So the honest version of the rule is that the boundary depends on the question: financing, statistics, a housing programme, a professional-licensing exemption, or a state statute. Anyone who tells you five units is the legal definition of commercial is compressing seven answers into one.
What actually changes above four units
The reason the finance boundary is the one that matters to a seller is that it is where valuation method changes, and valuation method is what determines the price.
Below it, a property is valued the way a house is valued: by comparison to similar properties that recently sold. Above it, the property is valued on the income it produces. Ada County follows the same split in its own assessment work — apartment properties are handled by commercial appraisers rather than residential ones, and commercial assessment runs on income.
That has a consequence owners often meet for the first time at the point of sale. The input to the valuation is the property's own operating performance, and the only person who holds that information is the owner. There is no portal that publishes it. This is the structural reason a commercial owner cannot approximate their own number the way a homeowner can, and it is not a marketing claim — it follows directly from the method.
What that means in practice
Because value follows income, the documents that describe income are the ones that matter. We ask for a rent roll and a trailing twelve months of operating statements, and for anything that changes what those numbers will look like next year: leases expiring, concessions, units held off the market, capital work that has been deferred.
The figure those documents produce is net operating income — in Freddie Mac's own definition, the income from a property's operations available for repayment of debt and return on equity to the owner, after deducting economic vacancy and all expenses, excluding debt service. That last exclusion is the part owners most often get wrong: NOI is a property-level number and is indifferent to how the building is financed. Two identical buildings with different loans have the same NOI.
A capitalization rate is then the percentage rate expressing the relationship between a property's value and the net operating income it produces. What rate applies to a particular building on a particular day is a market question, and we will not put a number on it here — an undated figure would be worth less than nothing to you.
None of that is a test to pass. Partly vacant, mid-turnaround, or in the middle of a repositioning is a normal condition for a building to be in, and it is a condition we can price. What we cannot do is price a building we cannot see the income of.
Where multifamily can go in Boise
Boise's mixed-use districts are the ones most relevant to apartment ground. MX-2 General is drawn for a mix of uses at a moderate scale and caps building height at 45 feet. MX-4 is built around transit-oriented development nodes. MX-5 Mixed-Use Downtown is the outlier in the code: its height cell reads N/A, with no footnote attached, where every other district read so far carries a maximum.
That last one deserves a caveat that its own table does not give it. No stated height maximum in the zoning table is not permission to build to any height downtown — design review, other overlays and requirements elsewhere in the code all still apply. It means the base district is not the binding constraint, which is a narrower statement than it first appears.
R-3 Residential Urban caps building height at four stories not to exceed 50 feet. Its density cell is a question we deliberately do not answer here: it is footnoted twice on the city's table, and the city does not publish the footnotes.
The assessor's number answers a different question
Assessed value in Ada County is market value as of January 1, produced for taxation at mass-appraisal scale rather than for a transaction. For most of the year it is a figure about a date in the past, and it carries a statutory tolerance and a rolling appraisal cycle behind it — all set out in how commercial value is determined.
None of that makes it the wrong number. It makes it the right number to a question a seller is not asking. It cannot account for the specific facts that move a real price on an apartment property — a block of leases rolling at once, a boiler at the end of its life, units held vacant through a turn.
What we do with multifamily property
Five units through several hundred, in Boise and across Ada County and selectively wider in the Treasure Valley. Stabilised, partly vacant, or mid-turnaround.
Timeline is set by the seller. We can work to a fast close or wait months where that is what the situation needs, and we are the party closing — not a party looking to assign the contract to someone else.
We will not tell you what your property is worth. We will tell you what we would pay and show how we got there.
Where this comes from
Every factual statement above is traced to a published source, quoted below in the source's own words. Zoning and assessment rules change; each entry carries the date we last checked it. Where a published table attaches a footnote we could not read, the figure is quoted with its marker rather than paraphrased.
12 CFR § 1282.1 — Definitions (FHFA, Enterprise Housing Goals)
Federal Housing Finance Agency / eCFR
At least six systems draw the residential/multifamily line differently, and no two of them agree in scope: Ada County assessment routes properties above four units to commercial appraisers; Idaho's disclosure act covers one to four dwelling units; Idaho's domestic water statute excludes multiple-dwelling developments with no unit count at all; the Census treats two units as multifamily and uses five only as a tabulation bracket; FHFA defines multifamily as more than four dwelling units for housing finance; and HUD's own programmes use two, five or eight depending on the programme.
Checked 2026-09-10 · Ada County, Idaho
The federal housing-finance definition that produces the familiar 1-4 versus 5+ split is in FHFA regulation: multifamily housing means a residence consisting of more than four dwelling units, and single-family housing means a residence consisting of one to four dwelling units.
“Multifamily housing means a residence consisting of more than four dwelling units. … Single-family housing means a residence consisting of one to four dwelling units.”
Checked 2026-09-10 · United States (federal)
Building Permits Survey — Definitions
U.S. Census Bureau
The U.S. Census Bureau treats a two-unit structure as multifamily. Its Building Permits Survey tabulates one-unit structures, then 2 units, 3 and 4 units combined, and 5 or more units — so five is where Census stops disaggregating, not where multifamily begins. The American Community Survey uses brackets of 1 detached, 1 attached, 2, 3 or 4, 5 to 9, 10 to 19, 20 to 49, and 50 or more.
“Multifamily structures are classified by the number of housing units in the structure. Data are tabulated for 2 units, 3 and 4 units combined, and 5 or more unit structures.”
Checked 2026-09-10 · United States (federal)
Descriptions of Multifamily Programs
U.S. Department of Housing and Urban Development
HUD has no single multifamily unit threshold. Its Section 207, 221(d)(4) and 223(f) programmes require five or more units, but Section 220 in urban renewal areas reaches two or more units and Section 231 rental housing for the elderly requires eight or more.
“Such property or project may include five or more family units and may include such commercial and community facilities as the Secretary deems adequate to serve the occupants.”
Checked 2026-09-10 · United States (federal)
Real & Manufactured Property Assessment — Ada County Assessor
Ada County Assessor
Idaho and Ada County do not use a single definition of where residential property ends and multifamily or commercial begins. At least three systems draw the line differently: county ASSESSMENT treats residential as up to four units and routes apartments to commercial appraisers; the property condition DISCLOSURE act applies to one to four dwelling units; and the domestic WATER statute excludes apartments, condominiums and similar multiple-dwelling developments generally rather than at a unit count.
Checked 2026-09-10 · Ada County, Idaho
Ada County develops commercial assessments using data on construction costs, market sales and income production; the residential approach described alongside it relies on construction costs, sales and, where applicable, rental information.
“Data pertaining to construction costs, market sales, and income-production is used to develop commercial assessments.”
Checked 2026-09-10 · Ada County, Idaho
Every non-exempt commercial property in Ada County is assessed at market value as of January 1, on the same annual cycle and the same five-year physical inspection requirement as residential property.
“Idaho law requires that all non-exempt property be assessed at market value as of January 1st.”
Checked 2026-09-10 · Ada County, Idaho
Idaho Code § 54-306 — Exemptions [from the Architects chapter]
Idaho State Legislature
Idaho's architects chapter does not apply to architectural services for a building used as a single or multiple family residence not exceeding three units or three stories in height. The exemption stops at three units, so a fourplex sits above it and a triplex does not — a boundary at three, in a state where other systems draw the line at two, four or five.
“The rendering of any architectural service required in the erection, enlargement, alteration or repair of any building, where the building is to be or is used as a single or multiple family residence not exceeding three (3) units or three (3) stories in height”
Checked 2026-09-10 · Idaho
Multifamily Seller/Servicer Guide — Glossary
Freddie Mac
Net operating income is the income from a property's operations available for repayment of debt and return on equity to the owner, after deducting economic vacancy and all expenses, excluding debt service.
“Net Operating Income is the income from a property's operations available for repayment of debt and return on equity to the owner after deducting economic vacancy and all expenses (exclusive of debt service).”
Checked 2026-09-10 · United States
A capitalization rate is the percentage rate representing the relationship between the value of a property and the net operating income it produces.
“The Capitalization Rate is the percentage rate that represents the proper relationship between the value of the Property and the Net Operating Income that the Property produces.”
Checked 2026-09-10 · United States
Assessor — Ada County
Ada County Assessor
Ada County's commercial appraisers, not its residential appraisers, value apartments and high-density residential — alongside office, retail and industrial.
“Our team of commercial appraisers handle valuation for all commercial property types, including, office, retail, industrial, and high-density residential (apartments) uses.”
Checked 2026-09-10 · Ada County, Idaho
Mixed-Use General (MX-2) Zoning District — City of Boise
City of Boise Planning and Development Services
Boise's MX-2 Mixed-Use General district provides for a mix of office, commercial, institutional and residential at a scale serving community needs broader than a nearby neighbourhood, with building height capped at 45 feet and front setbacks set as a range of minimum 0 to maximum 20 feet.
“The MX-2 district is intended to provide opportunities for a mix of office, commercial, institutional, and residential at a scale designed to serve community needs broader than those of nearby neighborhoods.”
Checked 2026-09-10 · Boise, Idaho
Mixed-Use Transit Oriented Development Node (MX-4) — City of Boise
City of Boise Planning and Development Services
Boise's MX-4 district supports transit-oriented development concentrated at identified transit stations, and the city states the district will be expanded as new best-in-class transit routes are added and stations identified.
“The MX-4 district is intended to provide opportunities for a mix of office, commercial, institutional, and residential uses to support transit. This zoning district will require transit-oriented development concentrated at identified transit stations. This zoning district will be expanded as new investments in best-in-class transit routes are added and transit stations identified.”
Checked 2026-09-10 · Boise, Idaho
Mixed-Use Downtown (MX-5) Zoning District — City of Boise
City of Boise Planning and Development Services
Boise's MX-5 Mixed-Use Downtown district states no maximum building height, where every other Boise district read so far carries one: MX-2 at 45 feet, R-3 at four stories not exceeding 50 feet, I-1 and I-2 at 55 feet, and I-3 at 150 feet.
“HEIGHT (MAXIMUM) D Building Height N/A”
Checked 2026-09-10 · Boise, Idaho
Boise's MX-5 district provides for a mix of higher-intensity office, commercial, institutional and residential uses, is intended to serve the Downtown Planning Area defined in the Comprehensive Plan, and sets front and side-street setbacks as a range of minimum 0 to maximum 20 feet with interior side and rear minimums of 0 feet.
“The MX-5 district is intended to provide opportunities for a mix of higher intensity office, commercial, institutional, and residential uses. The MX-5 district is intended to accommodate the needs of the city's Downtown Planning Area as defined in the Comprehensive Plan and to provide for activities conducive to a compact, concentrated, and walkable urban downtown mixed-use center.”
Checked 2026-09-10 · Boise, Idaho
Residential Urban (R-3) Zoning District — City of Boise
City of Boise Planning and Development Services
Boise's R-3 Residential Urban district caps building height at four stories not to exceed 50 feet.
“HEIGHT (MAXIMUM) D Building Height 4 stories not to exceed 50 ft.”
Checked 2026-09-10 · Boise, Idaho
The City of Boise's online zoning district pages reproduce each district's dimensional standards table together with its bracketed footnote markers, but do not publish the footnote definitions those markers point to. As accessed on 10 September 2026, the R-3 table carried markers [1] through [5], the I-3 table carried [1] through [3], and the I-1 and I-2 tables carried [1], and no definition for any of them appeared on any of those pages.
“LOT STANDARDS [1] Lot Area (minimum) [2] Single-Family Attached: 1,500 sf. All Other Uses: 2,00 sf. Lot Width (average) 20 ft. Street Frontage (minimum) 20 ft. Density (maximum) [2][3] N./A”
Checked 2026-09-10 · Boise, 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.