Chestertown MD ADU Rules 2026: 50% Size Rule, 1-Bedroom Cap, Historic Review & State-Law Conflict

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Last researched: September 19, 2026. Chestertown already has a detailed accessory dwelling unit section in its zoning ordinance, and the Town’s current Chapter 170 document is dated March 2, 2026. The code allows ADUs in residential districts R-3 through R-6 and permits them to be attached to or detached from the principal residence. But several parts of the posted rule no longer line up neatly with Maryland’s 2026 ADU framework.

Homeowner takeaway: Chestertown is not a “no ADU” town. The bigger issue is that its current public zoning text still contains older restrictions on lot area, size, bedrooms, parking and utilities. Before paying for plans, ask the Town’s Zoning Administrator whether Chapter 170 has been amended since March 2, 2026 and which provisions now control an HB 1466 application.

Chestertown ADU planning snapshot

Question What we verified
Current public zoning document Chestertown’s Chapter 170 zoning ordinance is dated March 2, 2026.
Where ADUs are listed The ADU definition says they can only be located in residential zoning districts R-3 through R-6, subject to the rest of the section.
Attached or detached? Both. The code says the ADU may be attached to or detached from the existing principal residence on the same lot.
Legacy lot-size threshold The ADU must meet the lot-area threshold used for two-family units in the applicable residential zone.
Legacy size formula The posted code says the ADU may not exceed 50% of the primary residence’s GHFA or 2,000 sq ft, with a 1,200-sq-ft footprint limit, using the phrase “whichever is greater.”
Bedroom limit The posted code allows no more than one bedroom.
Owner occupancy The current zoning text says the ADU is accessory only to an owner-occupied single-family residence.
Utilities A Town water/sewer hookup fee is required; separate laterals may be required if the Utilities Director determines existing lines are inadequate.
Parking / dimensional standards The code applies the principal-dwelling yard, height, lot-area, bulk, lot-coverage and parking requirements to the ADU.
Historic District Chestertown has a Historic District and a separate Historic District Commission review process for affected exterior work.
2026 state-law issue Maryland Planning says covered jurisdictions may not cap ADU size below 75% of the primary dwelling, and state law limits ADU side/rear setbacks and additional parking requirements.

Chestertown already permits attached and detached ADUs

Chestertown’s current zoning definition is unusually direct. It defines an accessory dwelling unit as an extra living unit on an owner-occupied residential property with kitchen, bathroom and sleeping facilities, and says the ADU may be inside, attached to or detached from the primary home.

The same section says ADUs can only be located in residentially zoned districts R-3 through R-6, unless excluded by deed restrictions or covenants within an approved subdivision.

For a homeowner, that means the first two checks are simple:

  1. confirm the property is actually inside Chestertown municipal limits; and
  2. confirm the current zoning district.

If the property is outside Town limits, use our Kent County ADU Rules guide instead. A Chestertown mailing address does not automatically mean Town zoning controls the parcel.

The two-family lot-area threshold is a real practical barrier

Chestertown’s current ADU section does more than require compliance with ordinary setbacks. It says the ADU must comply with the principal dwelling’s yard, height, lot-area, bulk, lot-coverage and parking requirements and adds that the lot-area requirement for two-family units is a threshold that must be met.

The Town itself has previously described this as an ADU barrier. In its Sustainable Communities renewal materials, Chestertown said its ADU rules were overly restrictive and specifically identified minimum lot area, off-street parking, utilities and zoning requirements as adding cost and time to ADU construction.

A real 2026 project shows why this matters. Chestertown’s Historic District Commission reviewed a proposed two-story ADU at 635 High Street in January 2026. The property owner planned to combine two lots, but even the combined area would remain below the required 5,000 square feet, so the project still needed a variance.

That example is useful because it shows that “ADUs are allowed” does not necessarily mean a conforming Town lot can proceed without dimensional relief.

Chestertown’s posted size formula needs a 2026 legal check

The March 2026 zoning text says the maximum Gross Habitable Floor Area (GHFA) of an ADU may not exceed 50% of the GHFA of the primary residence or 2,000 square feet, with a footprint not to exceed 1,200 square feet. The text literally ends that formula with “whichever is greater.”

Maryland’s statewide ADU definition now uses a different framework: the ADU may not be greater than 75% of the size of the primary single-family detached dwelling. Maryland Planning also says covered jurisdictions may not impose a local maximum below that 75% threshold.

The Chestertown formula therefore should not be used mechanically for a new 2026 design. Depending on the size of the primary house, the posted language can point to a maximum below 75% or, because of the “whichever is greater” wording, potentially to a figure above the state ADU definition.

Ask the Zoning Administrator which measurement rule is being applied now and whether an HB 1466 amendment has superseded the March 2026 wording.

Use our Maryland ADU size guide before choosing a plan, but rely on the Town for the parcel-specific measurement method.

Chestertown’s one-bedroom cap is another rule to verify

The current zoning text says the ADU may include a bathroom and kitchen but may have no more than one bedroom.

Maryland’s 2025 ADU law does not establish a statewide one-bedroom maximum in the ADU definition. It also says a local government may not prohibit or unreasonably restrict construction or rental of an ADU.

That does not automatically tell us that Chestertown’s one-bedroom rule has disappeared. It does mean the Town should be asked whether the one-bedroom cap remains part of its final HB 1466 implementation.

Owner occupancy remains in the posted Town code

Chestertown’s March 2026 zoning ordinance says an ADU is accessory only to an owner-occupied single-family residence. It also limits the lot to two dwelling units total: the principal residence and one ADU.

Homeowners planning a future move, long-term rental or estate transfer should confirm whether this owner-occupancy requirement remains unchanged in the Town’s final 2026 implementation rather than assuming the old language or a County rule controls.

Water and sewer can add cost even when zoning works

Chestertown’s ADU section requires a water and sewer hookup fee. It also says the Town’s Director of Utilities can require separate water and sewer laterals if the existing service lines are considered inadequately sized for the added usage.

This is one of the most practical Chestertown-specific cost checks. Before finalizing an ADU location or plumbing layout, ask the Utilities Department:

  • whether a new connection fee applies;
  • whether the existing service laterals are large enough;
  • whether separate laterals will be required;
  • whether a detached ADU needs separate metering; and
  • what utility work must be completed before occupancy.

Parking and setbacks also need an HB 1466 check

Chestertown’s current ADU language applies the principal dwelling’s parking and dimensional standards to the ADU. Maryland’s 2026 framework now limits local treatment in two important ways.

First, side and rear setbacks for an ADU may not be more restrictive than the jurisdiction’s existing setbacks for accessory structures. Second, if the Town imposes additional off-street parking requirements specifically because of an ADU, Maryland requires the required parking study and a waiver process.

Ask Chestertown which setback provision it now uses for a detached ADU and whether any additional parking requirement is supported by a completed parking study and current waiver procedure.

Historic District review can be a separate approval layer

Chestertown publishes a Historic District boundary map and maintains a Historic District Commission. The Town’s Planning & Zoning office provides separate Historic District guidelines and a Historic District building-permit application.

The January 2026 review of the proposed 635 High Street ADU demonstrates that this is not theoretical. A new detached ADU, second-story addition, garage conversion with exterior changes or other visible work in the Historic District can involve both zoning review and historic-design review.

Before buying a prefab design or finalizing exterior materials, confirm whether the property is in the Historic District and whether the proposed work requires a Certificate of Appropriateness or Historic District Commission approval.

Chestertown knows its ADU rules need reform

Chestertown has been publicly discussing ADU reform for several years. In its Sustainable Communities materials, the Town stated that current requirements create significant cost and time barriers and said the Planning Commission would review and revise the ADU requirements for greater flexibility.

The Town’s current draft comprehensive-plan materials also include an objective to permit accessory dwelling units in certain zones and streamline small-scale housing approvals.

As of this September 19, 2026 research pass, Chestertown’s 2026 legislation page lists Ordinances 01-2026 and 02-2026 but does not list a separate 2026 ADU ordinance. The public Chapter 170 file remains dated March 2, 2026.

That does not prove staff has made no administrative change or that an ordinance could not be adopted after this review. It does mean homeowners should ask for the current controlling text rather than assuming an internet summary is current.

What to ask Chestertown before paying for plans

  • Has Chapter 170’s ADU section been amended since March 2, 2026?
  • Which zoning districts currently permit ADUs?
  • Does the two-family lot-area threshold still apply?
  • What is the current maximum ADU size under Maryland’s 75% definition?
  • How does the Town calculate Gross Habitable Floor Area for the primary dwelling?
  • Does the one-bedroom maximum still apply?
  • Is owner occupancy still required?
  • What setback standard applies to a detached ADU?
  • What parking requirement applies and is there an ADU parking-waiver process?
  • Will the Utilities Director require separate water or sewer laterals?
  • What hookup fees apply?
  • Is the property inside the Historic District?
  • Will Historic District Commission review be required?
  • Does the lot need a variance because of lot size, setbacks or other nonconformities?

Chestertown homeowner checklist

  1. Confirm the property is inside Chestertown municipal limits.
  2. Check the zoning district.
  3. Ask the Zoning Administrator for the current ADU section and any 2026 amendments.
  4. Check whether the lot satisfies the current minimum lot-area requirement.
  5. Confirm the legal ADU size and measurement method.
  6. Determine whether the project is internal, attached or detached.
  7. Verify setbacks, height and lot coverage.
  8. Confirm whether the one-bedroom limit remains in effect.
  9. Check current owner-occupancy requirements.
  10. Confirm parking and any waiver procedure.
  11. Ask Utilities about hookup fees and separate laterals.
  12. Check Historic District status before exterior design work.
  13. Determine whether a variance or other Zoning Board of Appeals approval is needed.
  14. Do not make a non-refundable construction commitment until the Town confirms the current rules.

Chestertown MD ADU FAQs

Does Chestertown allow detached ADUs?

Yes under the current public zoning text. Chestertown defines ADUs as potentially inside, attached to or detached from the primary home, and says an ADU may be attached to or detached from the existing principal residence on the same lot.

Which Chestertown zoning districts allow ADUs?

The March 2, 2026 zoning ordinance says ADUs can only be located in residential districts R-3 through R-6, subject to the other ADU criteria and any later amendments.

What is the Chestertown ADU size limit?

The posted code uses a 50%-of-primary-residence / 2,000-square-foot formula with a 1,200-square-foot footprint limit and the wording “whichever is greater.” Maryland now defines an ADU as no greater than 75% of the primary dwelling and Maryland Planning says a covered jurisdiction cannot impose a lower local maximum. Ask Chestertown which rule is currently controlling before designing to a specific size.

Can a Chestertown ADU have two bedrooms?

The current public zoning text says no more than one bedroom. Because Maryland’s new ADU law does not use a statewide one-bedroom cap, confirm whether Chestertown has retained or amended that local restriction in its final 2026 implementation.

Do I need extra water and sewer work?

Possibly. Chestertown’s posted ADU rule requires a water/sewer hookup fee and allows the Utilities Director to require separate laterals if the existing lines are inadequate for the additional use.

Can a small Chestertown lot need a variance for an ADU?

Yes. The current code applies a two-family lot-area threshold. In January 2026, the Historic District Commission reviewed a proposed ADU at 635 High Street where even a planned lot-line adjustment would leave the combined property below a 5,000-square-foot threshold, requiring a variance.

Who should I contact about a Chestertown ADU?

Start with Chestertown Planning & Zoning. The Town lists Bradley Moore as Zoning Administrator at Town Hall, 118 N. Cross Street, Chestertown, Maryland 21620, with the main Town Hall number 410-778-0500.

Primary sources checked

Maryland ADU Guide is an independent research publication, not the Town of Chestertown, Kent County, a law firm, architect or contractor. Chestertown’s public zoning text predates the October 1, 2026 local-law deadline and contains provisions that should be checked against Maryland’s current ADU framework. Confirm the latest ordinance and parcel-specific requirements with the Town before spending money on design or construction.

YOUR NEXT PRACTICAL STEP

What to do next

Confirm the current Chestertown ADU section before choosing a floor plan or assuming your lot qualifies.

  1. Confirm who reviews the property.
  2. Ask Chestertown for any ADU amendment adopted after March 2, 2026.
  3. Gather your zoning district, survey, lot area and utility information.
  4. Continue to the Maryland ADU planning tools.

Planning guidance is not permit approval.