Last researched: September 19, 2026. Federalsburg has an unusual ADU setup. The Town’s general zoning chapter does not currently surface a simple townwide accessory-dwelling-unit use category, but its separate Critical Area chapter expressly regulates accessory dwelling units. In the Resource Conservation Area, § 45-18 allows one additional dwelling unit as part of a primary dwelling under stated sewage, location and size conditions, including the familiar 100-foot / 900-square-foot standard.
Homeowner takeaway: Do not confuse Federalsburg’s Critical Area ADU language with a complete townwide ADU ordinance. The Critical Area rule only applies when the use is permitted by the underlying zoning district. Before paying for plans, ask the Town which current zoning section authorizes ADUs generally and whether Federalsburg has adopted a separate HB 1466-compliant amendment since the public code was last updated.
Federalsburg ADU planning snapshot
| Question | What we verified |
|---|---|
| Local zoning authority | Federalsburg has municipal planning and zoning authority and its own Planning Commission. |
| Current public code status | The Town’s eCode site says it includes legislation through April 3, 2023, so later amendments should be confirmed directly with the Town. |
| General townwide ADU category | The current general zoning chapter does not surface a dedicated townwide ADU section comparable to the Critical Area chapter. |
| Critical Area ADU rule | Chapter 45 expressly lists “Accessory dwelling unit” as a permitted/conditional use in Critical Area designations if allowed by the underlying zoning district. |
| RCA standard | One additional dwelling unit may be permitted if served by the same sewage disposal system and either located within the primary dwelling, or entirely within 100 ft of it and no more than 900 sq ft of enclosed area. |
| Separate conveyance | The Critical Area ADU may not be subdivided or conveyed separately from the primary dwelling. |
| Tiny houses | Federalsburg separately regulates tiny houses as principal dwellings between 275 and 640 sq ft per floor in specified districts. A tiny house is not automatically an ADU. |
| Accessory-structure setback | The current zoning text says accessory buildings may be located in a side yard if at least 5 ft from lot lines. |
| 2026 state-law issue | Maryland requires covered municipalities to adopt an ADU law by October 1, 2026 and says the local maximum cannot be below 75% of the primary detached dwelling. |
Federalsburg’s Critical Area code expressly recognizes ADUs
Chapter 45 of Federalsburg’s code covers Chesapeake Bay Critical Area regulations. Its land-use table lists Accessory dwelling unit as:
- permitted in the Intensely Developed Area (IDA), if allowed by the underlying zoning district;
- permitted in the Limited Development Area (LDA), if allowed by the underlying zoning district; and
- permitted with conditions in the Resource Conservation Area (RCA), again only if the underlying zoning allows the use.
That last phrase is important. Chapter 45 does not itself create a townwide right to build an ADU. It adds environmental standards where an ADU is otherwise allowed by the parcel’s zoning.
The RCA rule uses the 100-foot / 900-sq-ft framework
Under § 45-18, one additional dwelling unit may be permitted in the RCA as part of a primary dwelling if it is served by the same sewage-disposal system as the primary dwelling and one of two location tests is met.
The first path allows the unit to be:
- inside the primary dwelling; or
- located so that its entire perimeter is within 100 feet of the primary dwelling and it does not exceed 900 square feet of total enclosed area.
The second path allows the additional unit within the primary dwelling where it does not increase lot coverage already attributed to the primary dwelling.
The same section says the additional unit may not be subdivided or conveyed separately from the primary dwelling.
The 900 sq ft figure is not a townwide maximum
This is a point homeowners can easily misread. The 900-square-foot language belongs to Federalsburg’s Critical Area RCA overlay. It is not a simple townwide statement that every Federalsburg ADU is limited to 900 square feet.
A parcel must first have an underlying zoning district that permits the ADU use. The Critical Area standard then adds its own environmental conditions.
Maryland’s statewide ADU definition now allows an ADU up to 75% of the size of the primary single-family detached dwelling, and the Maryland Department of Planning says covered jurisdictions may not impose a lower general local maximum.
That means a homeowner should not combine the state 75% rule and the RCA 900-square-foot language without asking the Town which rule applies to the actual parcel and why.
Federalsburg’s general zoning code does not currently give a clean townwide ADU answer
The Town’s current public Chapter 245 zoning code includes residential districts, accessory uses, accessory buildings, two-family dwellings, manufactured homes, tiny houses and other residential categories. During this September 19 research pass, I did not find a dedicated general-zoning section titled “Accessory Dwelling Unit” comparable to § 45-18 in the Critical Area chapter.
That does not mean Federalsburg prohibits ADUs. Maryland now requires municipalities with planning and zoning authority to adopt a local ADU law by October 1, 2026. It means homeowners need the Town’s current interpretation or later ordinance rather than relying on the public code index alone.
The Town’s eCode site also states that its online code includes legislation only through April 3, 2023. Later zoning amendments may exist outside that codified version.
Tiny houses are separately regulated and are not automatically ADUs
Federalsburg has a separate tiny-house section, § 245-119.4. That section defines a tiny house as a principal residential dwelling between 275 and 640 square feet per floor and allows tiny-house developments in the R-3, Town Center Redevelopment Overlay and Planned Unit Development districts, subject to Planning Commission approval and other conditions.
That is different from an ADU. An ADU is a secondary dwelling on the same lot as a primary single-family detached dwelling. A Federalsburg tiny house under § 245-119.4 is regulated as a principal dwelling in the permitted development context.
So a homeowner should not assume that a 500-square-foot tiny-house model can simply be placed in a backyard as an ADU because it meets the Town’s tiny-house definition.
Accessory-structure setbacks still matter for detached ADUs
Federalsburg’s general zoning ordinance says attached or detached accessory buildings may be constructed in a side yard if they are at least five feet from the lot lines. Other yard and district rules can also apply depending on the parcel.
Maryland’s HB 1466 framework now says a local ADU law may not establish side or rear setbacks that are more restrictive than the jurisdiction’s existing accessory-structure setbacks.
For a detached ADU, ask Federalsburg which accessory-building setbacks are being used as the HB 1466 benchmark and whether front-yard, corner-lot, lot-coverage or height rules add separate constraints.
Sewer and utility review can change the design
The Critical Area RCA provision specifically requires the additional dwelling unit to use the same sewage-disposal system as the primary dwelling. Federalsburg also has separate municipal water, sewer, sewage-disposal and utility provisions in its code.
Before finalizing an ADU layout, ask the Town whether the project triggers:
- water or sewer connection fees;
- a new meter;
- service-line upgrades;
- capacity review;
- private-septic approval where public sewer is unavailable; or
- Critical Area wastewater conditions.
Federalsburg zoning approval comes before construction
Chapter 245 requires a zoning certificate before a building is erected, altered, moved, converted, extended or enlarged. The zoning ordinance also provides for occupancy permits after applicable work is complete.
For an ADU, confirm the sequence with the Town before applying for construction permits. Depending on the proposal, the project may also need Planning Commission, Board of Appeals, Critical Area, floodplain, stormwater or utility review.
What Maryland’s 2026 ADU law changes for Federalsburg
Maryland’s HB 1466 framework requires local governments with planning and zoning authority to adopt a local law authorizing ADUs by October 1, 2026.
According to the Maryland Department of Planning, the local law must be consistent with several statewide requirements:
- the ADU definition allows a unit up to 75% of the size of the primary detached dwelling;
- a covered jurisdiction may not impose a lower maximum;
- ADUs must be excluded from density calculations;
- side and rear setbacks cannot exceed existing accessory-structure setbacks;
- additional off-street ADU parking requires a parking study; and
- any such parking requirement must include a waiver process.
Maryland also says the ADU can be attached or located in a separate structure, while jurisdictions may additionally permit wholly internal units.
Use our Maryland ADU size guide for the state framework, then confirm Federalsburg’s current ordinance before choosing a specific size.
We did not find a separately posted 2026 Federalsburg ADU ordinance
For this September 19, 2026 research pass, we checked Federalsburg’s current eCode, Chapter 245 zoning, Chapter 45 Critical Area provisions, the Town’s planning/zoning structure and Maryland Planning’s current HB 1466 guidance.
The online eCode currently says it includes legislation through April 3, 2023 and shows no uncodified “New Laws” in that system. I did not find a separately posted 2026 ordinance clearly identified as Federalsburg’s final HB 1466 ADU law.
That does not prove none has been adopted. It means a homeowner should ask the Town directly for any zoning amendment adopted after the public eCode supplement date.
What to ask Federalsburg before paying for plans
- What ordinance currently authorizes ADUs townwide?
- Has Federalsburg adopted its HB 1466-compliant ADU law?
- What is the ordinance number, adoption date and effective date?
- Which residential districts allow internal, attached and detached ADUs?
- How does the Town calculate Maryland’s 75% size limit?
- What accessory-structure setback applies to a detached ADU?
- What height and lot-coverage rules apply?
- What off-street parking requirement and waiver process apply?
- Has the Town completed a parking study if additional ADU parking is required?
- Is the parcel in the Chesapeake Bay Critical Area?
- If in the RCA, how do the 100-foot and 900-square-foot provisions apply?
- What sewer, septic, water or utility approvals are required?
- What zoning certificate, site plan or Board of Appeals review is required?
Federalsburg homeowner checklist
- Confirm the property is inside Federalsburg municipal limits.
- Identify the zoning district.
- Ask the Town for any ADU ordinance adopted after the current eCode supplement date.
- Do not assume the Critical Area 900-square-foot rule is the townwide maximum.
- Do not assume a tiny house is automatically an ADU.
- Confirm whether the project is internal, attached or detached.
- Verify the current size measurement.
- Verify setbacks, height and lot coverage.
- Check Critical Area status.
- Confirm parking and the waiver process.
- Check sewer, septic, water and utility requirements.
- Obtain the required zoning certificate before construction.
- Do not make a non-refundable prefab or construction commitment until the Town confirms the current rules.
Federalsburg MD ADU FAQs
Does Federalsburg allow ADUs?
Federalsburg’s Critical Area code expressly regulates accessory dwelling units, but only when the use is permitted by the underlying zoning district. The current public general zoning chapter does not provide a simple townwide ADU section, so ask the Town for its current HB 1466 implementation before applying.
Is the Federalsburg ADU maximum 900 sq ft?
Not necessarily. The 900-square-foot language appears in the Resource Conservation Area Critical Area standard. It is not a simple townwide maximum. Maryland’s statewide ADU definition allows up to 75% of the primary detached dwelling, subject to the current local ordinance and environmental rules.
Can I use a tiny house as an ADU in Federalsburg?
Do not assume so. Federalsburg’s tiny-house ordinance regulates tiny houses as principal dwellings in specified districts and development contexts. An ADU is a secondary unit on the same lot as a primary single-family detached dwelling and must satisfy the Town’s current ADU rules.
What if my property is in the Critical Area?
Federalsburg’s Critical Area chapter adds ADU standards, including same-sewage-system requirements and the 100-foot / 900-square-foot RCA provision. Those conditions apply in addition to whatever underlying zoning authorizes the use.
Who should I contact about a Federalsburg ADU?
Start with the Town of Federalsburg. Maryland Planning currently lists the Town’s Code Enforcement office at Town Hall, 118 North Main Street, Federalsburg, Maryland 21632, for local planning and zoning coordination.
Primary sources checked
- Town of Federalsburg — Municipal Code
- Town of Federalsburg — Chapter 245 Zoning
- Town of Federalsburg — § 45-18 Accessory Dwelling Unit, Critical Area
- Town of Federalsburg — Critical Area permitted-use table
- Town of Federalsburg — § 245-119.4 Tiny Houses
- Town of Federalsburg — accessory-building and supplementary zoning standards
- Maryland Department of Planning — local planning contacts
- Maryland Department of Planning — HB 1466 ADU FAQ
Maryland ADU Guide is an independent research publication, not the Town of Federalsburg, Caroline County, a law firm, architect or contractor. This page distinguishes Federalsburg’s explicit Critical Area ADU provisions from its general zoning code and notes that the public eCode currently says it includes legislation through April 3, 2023. Confirm any later ADU ordinance and parcel-specific requirements with the Town before spending money on design or construction.
What to do next
Confirm the current townwide ADU authorization first, then check whether Critical Area rules apply.
- Confirm who reviews the property.
- Ask Federalsburg for any ADU ordinance adopted after the public code’s supplement date.
- Gather your zoning district, survey, utility and Critical Area information.
- Continue to the Maryland ADU planning tools.
Planning guidance is not permit approval.