Maryland ADU HOA Rules: Can Your HOA Block an ADU?

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In Maryland, a homeowners association (HOA) cannot use neighborhood rules to effectively stop a qualifying homeowner from building or renting out an ADU. HB 1466 provides this protection, effective October 1, 2025.

But the law does not erase every HOA rule. As detailed in our comprehensive Maryland ADU guide, state law sets a floor while zoning, building requirements and some private-association rules still matter.

Last reviewed: September 6, 2026. This article is informational and is not legal advice. HOA disputes can turn on the exact language of recorded documents and should be reviewed by qualified Maryland counsel when necessary.

The Maryland ADU HOA law in plain English

Bottom line: a Maryland HOA generally cannot use private neighborhood rules to effectively block a qualifying ADU. But some HOA review, rental, voting and assessment rules can still matter.

What your HOA cannot do

  • Use a blanket or effective ADU banA private rule that explicitly—or in practice—prevents a qualifying ADU can be an unreasonable limitation.
  • Use private rules to unreasonably block renting the ADUHB 1466 also protects a qualifying owner’s ability to offer an ADU for rent from unreasonable private restrictions.

What your HOA can still do

  • Restrict short-term rentalsHB 1466 specifically says a short-term-rental restriction is not an unreasonable limitation for this provision. For the separate local-use rules, see our Maryland ADU rental and short-term rental guide.
  • Use architectural review proceduresDesign or exterior-review rules may still apply, but their practical effect still matters under the law.
  • Treat the ADU separately for voting and assessmentsThe HOA governing body may do this without legally subdividing your property.

Special case: certain historic properties are excluded from this private-restriction protection. Always check the actual HOA documents and your local ADU rules before spending money.

What HB 1466 actually says about private restrictions

HB 1466 amended Maryland’s Real Property Article. The rule reaches several types of private instruments, including declarations, contracts, HOA bylaws or rules, security instruments, deeds and other instruments affecting interests in real property.

For a property owner who has the exclusive right to use the property and complies with applicable laws and regulations, a land-use restriction may not impose an unreasonable limitation on the ability to develop or offer an ADU for rent.

Primary source: Chapter 197, 2025 Laws of Maryland.

What counts as an “unreasonable limitation”?

The final chaptered law defines an unreasonable limitation to include a restriction that prohibits, either explicitly or by effect, the development of an ADU.

That wording matters. An HOA does not necessarily need to write “ADUs are prohibited” for a restriction to be problematic. A rule may also be scrutinized if its practical effect is to prevent the ADU from being developed.

Maryland Department of Planning similarly explains that HOA bylaws may not impose unreasonable limitations on a property owner’s ability to develop an ADU or offer it for rent, and advises associations to consult legal counsel when evaluating their bylaws.

Official guidance: Maryland Department of Planning — HB 1466 FAQ.

Short-term rental restrictions are different

HB 1466 expressly says that a limitation on the short-term rental of an ADU is not an unreasonable limitation under this part of the Real Property Article.

So a homeowner should not assume that the state’s ADU protections create a right to operate the unit as an Airbnb-style rental. HOA rules and local short-term-rental laws may still apply.

HOA voting: the ADU can be treated as a separate lot

The law separately gives the governing body of a Maryland homeowners association authority to treat an ADU as a separate lot for purposes of voting on an HOA matter.

This provision concerns HOA governance. It should not be read as automatically subdividing the property, creating a separate deed, or changing the parcel for zoning or tax purposes.

HOA assessments: an ADU may also be counted separately

HB 1466 also authorizes the HOA governing body to treat an ADU as a separate lot for purposes of levying assessments.

That means a homeowner considering an ADU in an association-governed community should review not only design restrictions but also the potential ongoing HOA assessment impact.

Historic properties have a statutory exception

The private-restriction protection does not apply in the same way to certain historic properties. The chaptered law contains an exception for property listed in, or determined by the Maryland Historical Trust to be eligible for inclusion in, the Maryland Register of Historic Properties.

If your property has historic status, do not rely on the general HOA rule alone. Check the applicable historic-preservation requirements before design or construction decisions.

What to check in your HOA documents before you design

  1. Declaration and recorded covenants: Look for restrictions on accessory structures, second dwellings, leasing, exterior alterations and occupancy.
  2. Bylaws and rules: Check architectural-review procedures and any specific ADU language adopted after October 1, 2025.
  3. Architectural review: Determine what plans, elevations, materials or site drawings must be submitted.
  4. Rental rules: Separate long-term leasing rules from short-term-rental restrictions.
  5. Voting provisions: Ask whether the governing body intends to count the ADU separately for HOA voting.
  6. Assessment provisions: Ask whether the ADU will create an additional assessment obligation.
  7. Local zoning approval: HOA permission is not a substitute for county or municipal zoning and building approvals.

If your HOA says “ADUs are prohibited”

Do not assume the restriction is enforceable simply because it appears in an older declaration or rulebook. HB 1466 changed Maryland law effective October 1, 2025.

At the same time, do not ignore the association and proceed without review. The outcome can depend on whether the restriction actually prevents ADU development, whether the property qualifies for the statutory protection, whether historic-property rules apply, and whether the homeowner is complying with local laws.

A practical first step is to ask the HOA to identify the specific recorded provision it relies on and compare that language with the current Maryland statute. For a real dispute or significant financial commitment, consult a Maryland attorney familiar with real property and HOA law.

Primary sources

Maryland ADU Guide is maintained by Gijo John as an independent research publication. See our Editorial & Research Policy and Disclaimer.

YOUR NEXT PRACTICAL STEP

What to do next

Start by finding the office that reviews your property. A mailing city or a county guide does not establish your parcel’s authority.

  1. Find Who Reviews My Property.
  2. Obtain your parcel identifier, survey, floor plans and utility records.
  3. Ask the reviewing office which current rules, supporting documents and approvals apply.
  4. Continue to your planning workspace.

Enable JavaScript to prepare a downloadable next-step brief. Planning guidance is not permit approval.