Idaho SB 1354: Statewide ADU Rules and HOA Limits Explained (2026)

Idaho's S.B. 1354 makes an accessory dwelling unit a by-right use on single-family lots in cities over 10,000 people, and bars homeowner's associations from adding, amending, or enforcing covenants that ban ADUs without the owner's written consent. It took effect July 1, 2026; covered cities have until February 1, 2027, to comply.

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Idaho joined the statewide ADU wave in 2026, but SB 1354 is really two laws in one bill, and they do not cover the same ground. One piece rewrites the zoning rules for larger cities, forcing them to allow a backyard or in-home ADU by right. The other piece rewrites Idaho's homeowner's-association statute, and it reaches the whole state. Most summaries blur the two together and get the scope wrong. Here is what SB 1354 actually changed, what it left to your city or HOA, and the one provision that has real-estate attorneys openly uncertain.

SB 1354 at a Glance

SB 1354 fact	What the statute says	Source
Effective date	In full force and effect on and after July 1, 2026; signed March 31, 2026	[1][2]
Local compliance deadline	Covered cities must amend plans and ordinances by February 1, 2027	[1]
Cities covered (zoning mandate)	Only cities with a population greater than 10,000; counties and unincorporated land are not covered	[1]
HOA covenants (statewide)	An HOA may not add, amend, or enforce covenants that limit or prohibit ADUs unless the owner expressly agrees in writing — no population limit	[1]
ADUs required	At least one ADU per lot — either one internal ADU inside the home or one detached ADU in the rear yard	[1]
Minimum allowable size	City may not cap an ADU below 1,000 sq ft or 75% of the primary dwelling	[1]
Owner-occupancy	Covered cities are prohibited from requiring owner-occupancy	[1]
Parking	No off-street or guest parking may be required, subject to three narrow exceptions	[1]
Approval path	Conforming ADUs approved administratively and as a matter of right, no discretionary review	[1][3]

Bottom Line

Idaho S.B. 1354 (2026 Regular Session), titled simply "Accessory Dwelling Units," does two distinct things [1]. First, it adds a brand-new statute, Idaho Code § 67-6541, to the Local Land Use Planning Act, requiring cities over 10,000 people to treat an ADU as a by-right residential use on single-family lots. Second, it amends Idaho Code § 55-3212, the homeowner's-association statute, to bar HOAs from adding, amending, or enforcing covenants that limit or prohibit ADUs without the affected owner's written consent [1].

The bill was a State Affairs Committee bill. It passed the Senate 25-10 on March 20, 2026, and the House 47-23 on March 26, 2026. Governor Brad Little signed it on March 31, 2026 (Session Law Chapter 265), and its emergency clause set the law "in full force and effect on and after July 1, 2026" [1][2].

Three things to keep straight. The zoning mandate is not truly statewide: § 67-6541 applies "only to cities with a population greater than ten thousand (10,000)," and Idaho is a small-city state — roughly 85% of its incorporated cities sit below that line, and the statute never mentions counties or unincorporated land at all [1][4]. The HOA rule, by contrast, lives in Title 55 and carries no population limit, so it is statewide. And the July 1, 2026 effective date does not mean every covered city has a compliant ordinance yet — cities have until February 1, 2027, to update their codes, so there is a real-world lag [1].

Myth	Reality
"SB 1354 legalizes ADUs by right in every Idaho city."	No. The § 67-6541 zoning mandate binds only cities with a population greater than 10,000, and does not reach counties or unincorporated areas. Only the HOA covenant rule is statewide. [1]
"HOAs can no longer restrict ADUs at all."	No. HOAs may not add, amend, or enforce ADU-limiting covenants without the owner's written consent, but they may still adopt reasonable use rules (design, size, height, setbacks, parking, bedrooms), and existing recorded bans are legally uncertain. [1]
"Cities can never require ADU parking."	No. Parking generally may not be required, but the statute keeps three exceptions, including one that lets a city require parking within a quarter-mile of transit, jobs, or commercial services. [1]
"The size cap is a flat 75% of the house."	Not quite. A city may not limit an ADU below 1,000 sq ft or 75% of the primary dwelling — the 1,000-square-foot floor is part of the rule, not just the percentage. [1]
"Idaho lets cities require the owner to live on-site."	No. Covered cities are prohibited from imposing owner-occupancy on either unit — the opposite of Utah's SB 284. [1]

When Does Idaho SB 1354 Take Effect?

SB 1354 has two dates that matter, and confusing them is the most common error.

The law itself took effect July 1, 2026. Section 4 of the bill declares an emergency and states the act "shall be in full force and effect on and after July 1, 2026" [1]. Governor Little signed it March 31, 2026 [2]. So as of this writing in July 2026, SB 1354 is live law, not a future proposal.

The local compliance deadline is February 1, 2027. Section 67-6541(2) gives each covered city until that date to amend its comprehensive plan and land use regulations — through the normal notice-and-hearing process under Idaho Code § 67-6509 — to bring them into line with the mandate [1]. Between July 1, 2026 and February 1, 2027, a covered city may still be operating off its old ADU rules while it drafts amendments. The statutory right exists now, but the local ordinance that implements it arrives on each city's own schedule, up to the February 2027 backstop. If you are planning a project in this window, confirm in writing where your city stands.

Which Idaho Cities Does SB 1354 Apply To?

The zoning mandate in § 67-6541 applies only to cities with a population greater than 10,000 [1]. That single line does most of the work in defining scope, and it is why "statewide ADU law" is a loose description of the zoning piece.

Idaho's larger cities are clearly covered — Boise, Meridian, Nampa, Caldwell, Idaho Falls, Pocatello, Coeur d'Alene, Twin Falls, Post Falls, Rexburg, and other cities comfortably above 10,000 all fall inside the mandate [4]. But Idaho is overwhelmingly a state of small towns: the great majority of its incorporated cities are under 10,000 residents, and for those the § 67-6541 zoning mandate simply does not apply [4]. Resort and rural towns like Ketchum, Sun Valley, McCall, and Stanley are well below the line.

Two scope limits are easy to miss:

• Counties are not covered. Section 67-6541 speaks only of "cities" and repeatedly says "no city shall" and "each city governing board" [1]. Unincorporated county land — where a lot of Idaho's larger rural parcels sit — is outside this mandate entirely. If your property is in the county rather than inside city limits, SB 1354's zoning rules do not force the county to allow your ADU.
• The population line is a hard cutoff. A city at 9,800 people is not bound; a city at 10,200 is. If your city is near the threshold, ask the planning department directly whether it considers itself covered, because it decides whether the by-right path is available to you at all.

If your city is not covered, your ADU is governed by ordinary local zoning, and SB 1354's § 67-6541 changes nothing for you — though the HOA rule below may still apply.

What § 67-6541 Requires Covered Cities to Do

For cities over 10,000, § 67-6541 sets a floor. Every covered city must amend its code so that, on land zoned single-family residential (excluding designated historic districts and historic properties), the ordinance does the following [1]:

• Allow at least one ADU per lot. Specifically, "either one (1) internal accessory dwelling unit within the single-family dwelling or one (1) detached accessory dwelling unit per lot in the rear yard or subject to setbacks required of the primary dwelling." Read the "either/or" carefully: the mandate guarantees one ADU, satisfied by an internal or a detached unit; it does not on its face require a city to permit an internal and a detached unit on the same lot.
• Waive parking, with exceptions. The city must "prohibit requiring any off-street parking or guest parking for any accessory dwelling unit" — unless the principal dwelling has no off-street parking, or the street is not paved and built for on-street parking, or the principal dwelling is within one-fourth mile of transit, an employment area, or commercial services [1]. That last exception is worth flagging: in many states, proximity to transit waives parking, but here it is written as a condition that lets a city require it.
• Cap fees at the single-family level. The city may not impose impact fees or utility connection fees on an ADU that are greater than those charged on other single-family dwellings [1]. This limits fee gouging but does not make ADUs fee-free.
• Allow real size. The city may not limit an ADU "to less than one thousand (1000) square feet or seventy-five percent (75%) of the size of the primary dwelling" [1]. The 1,000-square-foot floor is part of the guarantee, not just the 75% figure.
• Ban owner-occupancy requirements. The city may not require the owner to live in the primary dwelling or the ADU [1].
• Allow full height. The city may not cap ADU building height below the height of an existing single-family primary dwelling on the lot [1].
• Not single out ADUs. The city may not apply setback, lot-size, coverage, or building-frontage rules to ADUs that are more restrictive than those applied to single-family dwellings in the same zoning district [1].

Then the procedural teeth: an ADU project that meets the jurisdiction's established land use requirements "shall be approved administratively and as a matter of right, without the need for discretionary approval" [1]. And any standards a city does adopt must be "clear and objective" and may not, singly or cumulatively, discourage ADUs "through unreasonable cost or delay" [1]. The Statement of Purpose frames the whole point as treating ADUs "as a residential use allowed by-right if certain conditions are met, with clear, objective standards for approval" [3].

What Cities Can Still Require

SB 1354 is a floor, not a deregulation of everything. Section 67-6541 expressly preserves state and local laws protecting public health, safety, and welfare, including [1]:

• Building codes, fire safety standards, and flood plain regulations.
• Water, sewer, storm drainage, road access, and utility-service laws needed to support the required density — a meaningful limit in areas on wells and septic or with constrained infrastructure.
• Environmental laws covering hazards, aquifer recharge zones, steep slopes, and critical habitat.
• Right-of-way and easement setback rules.

A city may also always go further than the mandate: "nothing in this section shall prohibit a city from enacting a regulation, standard, or condition that is less restrictive than the requirements of this section" [1]. So a covered city is free to allow more than one ADU, larger units, or ADUs on smaller lots — it just cannot fall below the § 67-6541 floor.

Can My HOA Still Ban an ADU in Idaho?

This is the provision to read slowly, because it is both the most powerful piece of SB 1354 and the least settled.

SB 1354 rewrites Idaho Code § 55-3212. The old version protected only internal ADUs and only against covenants that "strictly prohibit" them. The new version is far broader [1]:

"No homeowner's association shall add, amend, or enforce any covenant, condition, or restriction in such a way that limits or prohibits accessory dwelling units, as defined in section 67-6541, Idaho Code ... unless the owner of the affected property expressly agrees in writing to such addition or amendment of a covenant, condition, or restriction."

Two features make this reach much wider than the zoning mandate. It covers all ADUs — internal, attached, or detached, per the § 67-6541 definition — not just internal ones. And it carries no population limit, so it applies to an HOA in a town of 2,000 just as much as one in Boise. On the HOA side, SB 1354 really is statewide.

But here is the uncertainty. The prohibition covers three verbs — "add, amend, or enforce" — while the written-consent exception is phrased only around "such addition or amendment." The statute never says in plain terms what happens to an ADU ban that an HOA recorded before July 1, 2026. Because "enforce" is in the operative list, one reading is that HOAs cannot enforce even pre-existing ADU bans without owner consent. Because the consent carve-out and a narrow grandfather clause only address additions, amendments, and transfer restrictions, another reading is that already-recorded ADU bans survive. Real-estate attorneys have flagged exactly this gap; the honest answer today is that the enforceability of pre-July 2026 HOA ADU bans is genuinely unsettled and likely to be resolved by courts or a cleanup bill, not by the current text.

One thing the statute is clear about: even where the ban rule applies, an HOA keeps real authority. Section 55-3212(2) lets an HOA "adopt reasonable rules governing the use of accessory dwelling units otherwise allowed by law, including ... architectural design consistent with the primary dwelling, size limits, height limits, setback requirements, open space requirements, parking controls, and bedroom requirements" [1]. So "your HOA can't stop your ADU" overstates it. The HOA cannot flatly ban the unit through a new covenant without your written consent, but it can still regulate how the ADU looks, how big it is, and where it sits.

Practical takeaway for anyone in an HOA: do not assume a recorded ADU prohibition is still valid, and do not assume all HOA control has vanished. Pull your CC&Rs and have an Idaho attorney read § 55-3212 against them before you design or spend.

How Idaho SB 1354 Compares to Utah SB 284

Idaho's law arrives alongside a parallel move in Utah, and the contrast is instructive. Our companion guide, Utah SB 284: statewide detached ADUs explained, covers that state's approach in depth. In short:

Question	Idaho SB 1354	Utah SB 284
Who is bound	Cities over 10,000 population	"Specified municipalities" (by legal class)
Lot threshold	None (single-family residential land)	Lots 11,000 sq ft or larger
ADU types	Internal, attached, or detached	Detached ADUs specifically
Owner-occupancy	Cities prohibited from requiring it	Cities may require it
Effective posture	In effect July 1, 2026; comply by Feb 1, 2027	§ 10-21-304 operative Oct 1, 2026
HOA covenants	Statewide limit on ADU-banning covenants	Not the focus of the bill

The common thread is state preemption of purely discretionary local denial. The differences are in mechanics: Idaho keys to city population and bakes in a statewide HOA rule and an owner-occupancy ban, while Utah keys to lot size and municipal class and lets cities keep owner-occupancy and short-term-rental limits. If you are comparing states for an ADU investment, those owner-occupancy and rental differences change the math.

What Idaho SB 1354 Does Not Say

Several claims circulating online run ahead of the statute. To be precise about the gaps [1]:

• It does not address short-term or vacation rentals. Section 67-6541 is silent on rental duration, and § 55-3212 carries only a narrow carve-out for certain rentals defined elsewhere in Idaho Code. SB 1354 neither guarantees nor bans Airbnb-style use of an ADU; your city's separate short-term-rental ordinance still controls.
• It does not make ADUs fee-free. It caps ADU impact and connection fees at the single-family level — it does not eliminate them.
• It does not force cities to allow two ADUs per lot. The mandate is one ADU, satisfied by an internal or a detached unit.
• It does not reach counties or small cities. The zoning mandate stops at cities over 10,000; unincorporated land and smaller towns are outside it.
• It does not clearly void existing HOA ADU bans. As above, the enforceability of pre-July 2026 recorded prohibitions is unsettled.

What To Do Now

A practical sequence for an Idaho homeowner or buyer weighing an ADU under SB 1354:

1. Confirm your city is covered. Ask whether your city's population exceeds 10,000, and whether your parcel is inside city limits (not unincorporated county) [1]. If not, the zoning mandate does not apply.
2. Check the ordinance calendar. The law is in effect, but your city has until February 1, 2027, to update its code. Ask the planning department whether its compliant ADU ordinance is adopted yet, and get the current standards in writing [1].
3. Read your CC&Rs. If you are in an HOA, have an Idaho attorney assess whether any ADU restriction survives § 55-3212, and remember the HOA can still impose reasonable design, size, and setback rules [1].
4. Size the unit against the floor. Confirm your city cannot cap the ADU below 1,000 sq ft or 75% of your home, and cannot hold its height below your main dwelling's [1].
5. Model the parking and infrastructure. Check whether any of the three parking exceptions apply to your lot, and whether water, sewer, and utility-capacity rules constrain a new unit [1].
6. Run the feasibility numbers early. Tools like ADU Pilot can help translate a lot's zoning, setbacks, and size limits into what you can actually build before you commit to a design.

Frequently Asked Questions

When does Idaho SB 1354 take effect? SB 1354 took effect July 1, 2026, the date fixed in its emergency clause after Governor Little signed it on March 31, 2026. Covered cities then have until February 1, 2027, to amend their comprehensive plans and land use ordinances to comply with the new law [1][2].

Does Idaho SB 1354 apply to Boise and every Idaho city? The zoning mandate in Idaho Code § 67-6541 applies only to cities with a population greater than 10,000, so Boise, Meridian, and Nampa are covered while most smaller Idaho towns and all unincorporated county land are not. The separate HOA covenant rule applies statewide, regardless of city size [1][4].

Can my HOA still ban an ADU in Idaho? It is unsettled. SB 1354 bars an HOA from adding, amending, or enforcing covenants that limit ADUs unless the owner agrees in writing, but the statute does not clearly say whether ADU bans recorded before July 1, 2026, stay enforceable. Get legal advice on your specific CC&Rs [1].

How big of an ADU does Idaho SB 1354 allow? Covered cities may not cap an ADU below 1,000 square feet or 75% of the primary dwelling's size. They also cannot limit ADU height below the existing main dwelling's height, or impose setbacks, lot-size, or coverage rules stricter than those single-family homes face in the same zone [1].

Does Idaho SB 1354 require owner-occupancy? No — it forbids it. Covered cities are prohibited from requiring the owner to live in either the primary dwelling or the ADU. That is the opposite of Utah's SB 284, which lets covered cities keep an owner-occupancy rule. Whether an HOA may impose one is a separate, unsettled question [1].

Does Idaho SB 1354 require parking for an ADU? Usually no. Covered cities must waive off-street and guest parking for ADUs, but the statute keeps narrow exceptions: where the main home lacks off-street parking, the street cannot support on-street parking, or the home sits within a quarter-mile of transit, an employment area, or commercial services [1].

References

1. [1] Idaho State Legislature, "Senate Bill 1354, As Amended (Engrossed) — Accessory Dwelling Units." Enacted bill text amending Idaho Code § 55-3212 (HOA covenant rule: no add/amend/enforce of ADU-limiting covenants without the owner's written consent; reasonable-use rules preserved) and adding Idaho Code § 67-6541 (by-right ADU mandate for cities over 10,000: one ADU per lot, parking waiver and exceptions, 1,000 sq ft / 75% size floor, owner-occupancy prohibition, height and setback parity, February 1, 2027 compliance deadline, public-health savings clause, emergency effective date July 1, 2026). https://legislature.idaho.gov/wp-content/uploads/sessioninfo/2026/legislation/S1354E1.pdf
2. [2] Idaho State Legislature, "S1354 — Bill Status and Legislative History." Sponsor (State Affairs Committee), Senate vote 25-10 (March 20, 2026), House vote 47-23 (March 26, 2026), Governor signed March 31, 2026, Session Law Chapter 265, effective July 1, 2026. https://legislature.idaho.gov/sessioninfo/2026/legislation/S1354/
3. [3] Idaho State Legislature, "S1354 — Statement of Purpose / Fiscal Note (Revised)." Legislative sponsors' summary describing SB 1354 as treating ADUs "as a residential use allowed by-right if certain conditions are met, with clear, objective standards for approval." https://legislature.idaho.gov/wp-content/uploads/sessioninfo/2026/legislation/S1354SOP.pdf
4. [4] Idaho Demographics / U.S. Census population estimates, "Idaho Cities by Population." Population data confirming which Idaho cities exceed the 10,000 threshold (Boise, Meridian, Nampa, Caldwell, Idaho Falls, Pocatello, Coeur d'Alene, Twin Falls, Post Falls, Rexburg, and others) and that the large majority of Idaho's incorporated cities fall below it. https://www.idaho-demographics.com/cities_by_population

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