If you live in a Boise neighborhood with an HOA and you’re thinking about building an ADU, you’re probably wondering whether your HOA can say no. If you’re new to ADUs generally, our complete guide to building an ADU in Boise covers the basics; here’s exactly what Idaho law says your HOA can and can’t do.
The Law: Idaho Code §55-3212
Idaho Code §55-3212 puts a clear limit on HOA power over accessory dwelling units. An HOA cannot add, amend, or enforce any covenant, condition, or restriction that limits or prohibits ADUs — as defined under Idaho Code §67-6541 — anywhere within its jurisdiction. That protection applies unless the property owner expressly agrees, in writing, to the restriction.
The Pre-Existing Covenant Exception
There’s one important carve-out, and it’s easy to misread. This law doesn’t undo covenants that already existed and applied to a property before the current owner acquired it — specifically ones limiting or prohibiting a property owner’s right to transfer an interest in the land or structures. In plain terms: this protects your right to build an ADU, but it doesn’t override every older restriction tied to how the ADU can be sold or transferred.
Bottom line: Your HOA can’t ban your ADU outright, but it can still shape how it looks, where it sits on the lot, and how big it is — as long as those rules are reasonable and don’t amount to a de facto ban.
What Your HOA Can Still Control
This law limits an HOA’s power to ban ADUs — it doesn’t remove all authority over them. HOAs can still adopt reasonable rules governing how an ADU looks and functions:
| HOAs Can Still Regulate |
| Architectural design, to stay consistent with the primary home |
| Size limits |
| Height limits |
| Setback requirements |
| Open space requirements |
| Parking controls |
| Bedroom requirements |
What This Law Doesn’t Cover
This protection doesn’t stop your HOA from adopting less restrictive ADU rules than the law requires — HOAs are always free to be more permissive. It also doesn’t apply to certain rentals as defined under Idaho Code §63-1803(4); we don’t have that section’s exact text on hand, so if your property may fall into that category, confirm directly with a professional rather than relying on this article alone.
What This Means for Boise Homeowners with an HOA
If your HOA has told you ADUs simply aren’t allowed on your lot, that blanket answer likely isn’t enforceable under current Idaho law — unless a pre-existing transfer-related covenant applies to your specific property. What your HOA can still do is require your design, size, and placement to meet its reasonable standards. Mode Homes designs ADUs that work within both the zoning code and typical HOA design standards, so this usually isn’t an either/or situation.
Not sure how your HOA’s rules apply to your ADU plans? We’ll help you sort out what’s actually enforceable and design a project that fits your neighborhood’s standards.
Frequently Asked Questions
Can my HOA legally ban ADUs in Idaho?
No — Idaho Code §55-3212 prohibits HOAs from banning ADUs, unless a pre-existing covenant limiting property transfer already applied before you acquired the property.
Can my HOA still require design approval for my ADU?
Yes. HOAs can require the ADU’s architectural design to be consistent with the primary home, along with reasonable size, height, setback, and parking rules.
What if my HOA’s covenants already ban ADUs?
If that covenant predates your ownership and specifically restricts your right to transfer the property, it may still apply. If it’s a general use restriction added or enforced after this law, it’s likely unenforceable.
