Last researched: September 19, 2026. Westminster is a different kind of ADU jurisdiction from towns that already publish a dedicated accessory dwelling unit section. During this review, I did not find a standalone “Accessory Dwelling Unit” provision in the City’s current Chapter 164 zoning code. Yet Westminster has already approved real accessory dwelling unit projects through its water and sewer allocation process, including an ADU at 152 Bond Street and another at 34 Kate Wagner Court.
Homeowner takeaway: An ADU in Westminster is not just a zoning question. Water and sewer capacity can be a separate gate before a building permit is issued. Before paying for plans, ask the City’s Community Planning & Development Department which zoning pathway applies to your parcel and whether the project needs additional water/sewer allocation or a Good Cause Waiver.
Westminster ADU planning snapshot
| Question | What we verified |
|---|---|
| Dedicated ADU zoning section located? | No standalone ADU section was located in the current Chapter 164 materials reviewed on September 19, 2026. |
| Real ADU approvals? | Yes. City records document water/sewer Good Cause Waivers for ADUs at 152 Bond Street and 34 Kate Wagner Court. |
| Water allocation | The City’s allocation policy says projects requiring new or additional water cannot receive building permits without approved allocation. |
| Water-resource constraint | The City’s current policy says Westminster remains under an MDE Consent Order regarding water resources. |
| Accessory-building location | Current § 164-147 generally confines accessory buildings to rear yards. |
| Accessory-building setback | Current § 164-147 generally requires 8 ft from alley lines and from lot lines adjoining lots in residential zones. |
| Accessory-building height | Varies by district; current residential-zone provisions commonly cap accessory buildings at 20–25 ft. |
| Rental licensing | Every rental unit in Westminster must be licensed annually before it can be rented or leased. |
| 2026 state-law issue | Maryland requires covered municipalities to implement ADUs under the statewide 75% size, setback and parking framework. |
Westminster has already processed real ADUs
The clearest evidence that Westminster is already dealing with ADUs is not a zoning-code heading. It is the City’s own water and sewer allocation record.
In late 2023, the Mayor and Common Council approved Good Cause Waiver 23-03 for additional water and sewer allocation for an accessory dwelling unit inside the existing single-family detached dwelling at 152 Bond Street.
The City’s FY2026 materials also report approval of Good Cause Waiver 25-01 for additional water and sewer allocation for an accessory dwelling unit in an existing single-family detached residence at 34 Kate Wagner Court.
These examples matter because they show that Westminster homeowners have successfully moved ADU projects through the City’s infrastructure-allocation system. They do not prove that every lot or every detached ADU configuration is permitted.
Water allocation can be a permit gate in Westminster
Westminster’s Water and Sewer Allocations Policy says the City remains under a Maryland Department of the Environment Consent Order regarding its water resources.
The policy says development approvals and building permits for projects that require new or additional water cannot be granted without an allocation approved through the City’s allocation system and consistent with MDE requirements.
That makes Westminster different from a jurisdiction where a homeowner can focus only on setbacks and floor area. An otherwise buildable ADU can still require a separate utility-capacity decision.
Before final design, ask:
- whether the ADU creates additional water demand requiring allocation;
- whether sewer allocation is also required;
- whether the project qualifies under an existing allocation category;
- whether a Good Cause Waiver is needed;
- what fixture or demand assumptions the City will use; and
- whether allocation must be final before the building permit is released.
A Good Cause Waiver is not the same thing as zoning approval
The Bond Street and Kate Wagner Court examples document utility-allocation approvals. A water/sewer waiver does not replace zoning approval, building-code review or other required permits.
For a new Westminster ADU, ask the City to identify the zoning basis for the project separately from the utility-allocation path.
We did not locate a clean dedicated ADU section in Chapter 164
During this September 19 research pass, I reviewed Westminster’s current residential-zone articles, definitions, special provisions and the current “New Laws” notices in Chapter 164.
The residential zones continue to list single-family detached dwellings and customary accessory uses/buildings, while the R-7,500 zone separately allows conversion dwellings by special exception subject to § 164-150. I did not locate a standalone section titled “Accessory Dwelling Unit” in the current City of Westminster, Maryland zoning code.
That is why this page does not invent a Westminster-specific ADU size, bedroom, owner-occupancy or district table. Ask the Zoning Administrator which current section the City is using for an ADU application and whether an HB 1466 amendment has been adopted but not yet clearly indexed.
Do not confuse “conversion dwelling” with an ADU without City confirmation
Westminster’s zoning code has an older category called a conversion dwelling. The definition covers an existing building converted or altered to accommodate two or more families as a rental facility, condominium or cooperative, subject to § 164-150.
R-7,500 lists conversion dwellings as a special exception.
That category may overlap with some internal-conversion situations, but it is not written as the modern Maryland ADU framework. Do not assume a proposed ADU must—or must not—use the conversion-dwelling pathway without a written interpretation from the City.
Accessory buildings generally belong in the rear yard with 8-ft setbacks
Westminster’s current § 164-147 says accessory buildings are generally confined to rear yards.
The same section generally requires accessory buildings to be at least 8 feet from alley lines and from lot lines adjoining lots in residential zones.
Maryland’s current ADU framework says a local government may not impose ADU side and rear setbacks that are more restrictive than its existing accessory-structure setbacks.
For a detached ADU, the 8-foot accessory-building standard is therefore an important benchmark to ask about. Corner-lot rules, zoning-district setbacks, lot coverage and other provisions can still affect the final placement.
Accessory-building height varies by Westminster zoning district
Westminster does not use one universal accessory-building height across every residential zone.
Examples from the current code include:
- R-20,000: accessory buildings up to 20 ft;
- R-10,000: accessory buildings up to 25 ft; and
- R-7,500: accessory buildings up to 25 ft.
A detached ADU therefore needs a parcel-specific zoning-district check rather than a single citywide height assumption.
Maryland’s 75% rule still applies to the City’s 2026 implementation
Maryland’s current ADU law defines an ADU as a secondary dwelling unit on the same lot as a primary single-family detached dwelling and allows the ADU to be up to 75% of the size of the primary dwelling.
The Maryland Department of Planning says covered jurisdictions may not impose a local maximum below that 75% threshold.
The state framework also says:
- ADUs are excluded from residential-density calculations;
- side and rear ADU setbacks cannot exceed existing accessory-structure setbacks;
- additional off-street ADU parking requires the state-required parking study; and
- a local law imposing extra parking must include a waiver process.
Use our Maryland ADU size guide to understand the statewide framework, but ask Westminster how the City is applying it in its zoning code.
If the ADU will be rented, it needs a Westminster rental license
Westminster’s Rental Housing License Program says every rental unit in the City must be licensed annually before it can be rented or leased.
The current program uses a sliding annual fee schedule based on when the license is obtained. The listed fee is lowest in July and increases for late licensing.
If an ADU will be leased, ask:
- whether the ADU is entered as a separate rental unit;
- whether a separate inspection is required;
- whether lead-law documentation applies;
- what annual fee is due; and
- whether the final ADU ordinance adds owner-occupancy or rental-duration conditions.
Westminster’s water constraint makes early utility screening especially important
The City’s current Water and Sewer Allocations Policy is built around limited regulated capacity. Westminster tracks how much water can be allocated and distributes capacity through categories and a formal approval process.
For an ADU homeowner, the practical lesson is simple: do not wait until finished construction drawings to ask about water allocation.
A short early conversation with Community Planning & Development and the City’s water/sewer allocation staff can determine whether the project needs a Good Cause Waiver and whether capacity is available.
What to ask Westminster before paying for ADU plans
- What current zoning section authorizes an ADU on my parcel?
- Has Westminster adopted an HB 1466-specific ADU zoning amendment?
- Which residential zoning districts currently allow internal, attached and detached ADUs?
- What size-measurement method does the City use for Maryland’s 75% rule?
- Is owner occupancy required?
- What accessory-building setbacks apply to a detached ADU?
- What height and lot-coverage rules apply in my zoning district?
- What parking requirement and waiver process apply?
- Has the City completed the ADU parking study required if additional parking is imposed?
- Does the project require new or additional water allocation?
- Does it require sewer allocation?
- Is a Good Cause Waiver needed?
- What building, electrical, plumbing and occupancy approvals are required?
- If rented, how should the ADU be licensed under the Rental Housing License Program?
Westminster homeowner checklist
- Confirm the property is inside Westminster City limits.
- Identify the zoning district.
- Ask the Zoning Administrator for the current ADU zoning pathway.
- Do not assume “conversion dwelling” automatically equals ADU.
- Confirm the Maryland 75% size calculation used by the City.
- For a detached ADU, check the 8-ft accessory-building setback benchmark and district height.
- Ask about water and sewer allocation before final design.
- Determine whether a Good Cause Waiver is required.
- Confirm parking and any waiver process.
- Prepare the site plan and building documents required by the City.
- If renting, obtain the required rental license before occupancy.
- Do not make a non-refundable construction commitment until zoning and utility allocation are both confirmed.
Westminster MD ADU FAQs
Does Westminster allow ADUs?
City records show that Westminster has approved real accessory dwelling unit projects through its water/sewer allocation process, including internal ADUs at 152 Bond Street and 34 Kate Wagner Court. During this review, however, we did not locate a clean dedicated ADU section in the current Chapter 164 zoning code. Ask the City which zoning pathway applies to your parcel.
Why would a Westminster ADU need a water-allocation waiver?
Westminster’s Water and Sewer Allocations Policy says projects requiring new or additional water cannot receive building permits without approved allocation. The City remains under an MDE Consent Order regarding water resources, so added dwelling demand can require allocation review or a Good Cause Waiver.
What are Westminster’s accessory-building setbacks?
Current § 164-147 generally confines accessory buildings to rear yards and requires at least 8 feet from alley lines and from lot lines adjoining lots in residential zones. Confirm how Westminster applies that standard to a detached ADU under Maryland’s current setback rule.
How tall can an accessory building be?
It depends on the zoning district. Current residential examples range from 20 ft in R-20,000 to 25 ft in R-10,000 and R-7,500. Confirm the parcel-specific rule.
Can I rent a Westminster ADU?
Every rental unit in Westminster must be licensed annually before it is rented or leased. Ask whether the ADU also has zoning-specific owner-occupancy or rental conditions under the City’s current 2026 ADU implementation.
Who should I contact about a Westminster ADU?
Start with the City of Westminster Department of Community Planning & Development at 45 W. Main Street, Westminster, Maryland 21157. The City lists 410-848-9002 for planning and zoning questions.
Primary sources checked
- City of Westminster — Community Planning & Development
- City of Westminster — Zoning
- City of Westminster — Article XX Special Provisions / § 164-147 Accessory Buildings
- City of Westminster — Water and Sewer Allocations Policy
- City of Westminster — FY2026 Budget / Good Cause Waiver 25-01 ADU record
- City of Westminster — Bond Street ADU Good Cause Waiver approval record
- City of Westminster — Rental Housing License Program
- Maryland Department of Planning — HB 1466 ADU FAQ
Maryland ADU Guide is an independent research publication, not the City of Westminster, Carroll County, a law firm, architect or contractor. This page states exactly what was checked: Westminster’s current zoning code, accessory-building rules, water/sewer allocation policy, real ADU allocation records, rental-license program and Maryland’s HB 1466 guidance. Confirm the current zoning pathway, utility allocation and parcel-specific requirements with the City before spending money on design or construction.
What to do next
In Westminster, confirm both zoning and water/sewer allocation before committing to an ADU design.
- Confirm who reviews the property.
- Ask Westminster Planning which zoning pathway applies to the ADU.
- Ask whether additional water/sewer allocation or a Good Cause Waiver is required.
- Continue to the Maryland ADU planning tools.
Planning guidance is not permit approval.