Quick answer: On ordinary standard-method lots, published shed and garage side/rear minimums start at 5/5 ft in R-60 and R-90, 12/7 ft in R-200, and 15/10 ft in RE-1 and RE-2. These are accessory-structure figures; a detached ADU needs a separate use-specific check. A five-foot shed setback is not a countywide answer: the published R-200 accessory-structure table starts at 12 feet on the side and seven feet at the rear. R-60 and R-90 start at five feet, but taller or longer buildings can require more space.
First, check which jurisdiction controls your property. Use this guide for lots governed by Montgomery County zoning; confirm the applicable authority before using County tables for a municipal address. For ADU eligibility and the approval process, see the Montgomery County ADU guide.
Sources checked October 5, 2026. The tables below summarize the published zoning code for standard-method detached-house lots. They are a starting point for a site plan, not approval of a particular location. The ADU amendment verification issue is explained separately below.
Shed and detached-garage setback table
Start with the accessory-structure standards for your zone. This table covers ordinary non-dwelling accessory structures under the standard method of development. Cluster development, MPDU provisions, other zones and lot-specific approvals need their own review.
| Published standard | R-60 | R-90 | R-200 | RE-1 | RE-2 |
|---|---|---|---|---|---|
| Front setback | 60 ft | 60 ft | 65 ft | 80 ft | 80 ft |
| Interior side setback | 5 ft | 5 ft | 12 ft | 15 ft | 15 ft |
| Ordinary rear setback | 5 ft | 5 ft | 7 ft | 10 ft | 10 ft |
| Side street setback* | 25 ft / otherwise 15 ft | 30 ft / otherwise 15 ft | 40 ft / otherwise 15 ft | 50 ft / otherwise 20 ft | 50 ft / otherwise 20 ft |
| Rear setback on qualifying corner lot* | 10 ft / otherwise 5 ft | 10 ft / otherwise 5 ft | 12 ft / otherwise 7 ft | 12 ft / otherwise 10 ft | 12 ft / otherwise 10 ft |
| Maximum accessory-structure height | 20 ft | 20 ft | 35 ft | 50 ft | 50 ft |
*The larger side-street and corner-rear figures apply when the abutting lot fronts on the side street and is in a Residential Detached zone. All three tables also require the accessory structure to sit behind the principal building’s rear building line, in addition to meeting the front setback. Sources: §59.4.4.9.B, R-60; §59.4.4.8.B, R-90; §59.4.4.7.B, R-200; §59.4.4.6.B, RE-1; §59.4.4.4.B, RE-2. RE-1/RE-2 lots abutting a national historical park also have a 200-foot accessory-structure buffer unless the cited code exception applies.
Read the lot lines before choosing a building location
A setback is the required distance between a structure and the relevant lot line. County code distinguishes front, side street, interior side and rear lines; a through lot has two front setbacks. Use Montgomery Planning’s Digital Zoning Finder to identify the zone, then use a boundary survey to locate the lines. The main house and a detached accessory structure have different placement tables. See §59.4.1.7.B.1.
Shed and garage setback estimator
Shed and garage setback estimator
For ordinary non-dwelling accessory buildings on standard-method lots under County zoning. Select ADU or a special lot to see the verification step instead of a misleading number. Sources: the zone tables linked above.
Select your zone and enter the dimensions to calculate the published ordinary-lot reference.
Results exclude easements, coverage, projections, fire-code review, historical-park buffers and special approvals. The ADU Feasibility Checker helps organize the wider dwelling project.
When five feet becomes nine feet
The R-60 and R-90 tables increase minimum side and rear setbacks by two feet for each foot of building height above 15 feet. Separately, when a structure’s length along a side or rear lot line exceeds 24 feet, the corresponding setback increases by two feet for each two feet of extra length.
Height example: An R-60 accessory building that is 17 feet high and 22 feet long starts with a five-foot ordinary side or rear setback. Its two feet of height above 15 add four feet: 5 + 4 = 9 feet.
Length example: An R-90 accessory building that is 14 feet high and 28 feet long along a side lot line has four feet of excess length. That adds four feet to the five-foot side minimum: 5 + 4 = 9 feet. These examples isolate one adjustment each; ask DPS how it calculates a design that triggers both or has fractional dimensions.
The published R-200 standard-method accessory table does not list those R-60/R-90 adjustment formulas. Use its own standards rather than transferring a rule from another zone. A building can also meet its maximum permitted height while needing a larger setback.
Does a shed under 200 square feet need a permit?
Yes. The DPS shed guidelines, revised April 15, 2025, require a building permit for any shed installation or construction. A single-story shed of 200 square feet or less avoids structural review, but still needs a final inspection for its location and anchorage. Size does not waive zoning setbacks.
For those small sheds, DPS requests a permit application and a scaled site plan showing the proposed shed, existing structures and distances to lot lines, based on an accurate boundary survey. An attached shed is treated as an addition and follows different review procedures. Before ordering, use our Maryland ADU site-plan guide to organize the site information; follow DPS’s shed-specific submission requirements for a shed application.
Can I use these setbacks for a detached ADU?
Do not assume that a shed or garage location also qualifies for a dwelling. A future conversion changes the zoning question. Ask DPS to evaluate the intended ADU use before committing to a new garage or purchasing a structure for conversion.
The published §59.3.3.3.C still shows the older detached-ADU provisions: buildings constructed after May 30, 2012 use the principal dwelling’s minimum side setback and a 12-foot rear minimum. Length beyond 24 feet adds one foot of corresponding setback per extra foot; the rear calculation starts at 12 feet.
That section also has an exception for legally constructed structures dating before May 31, 2012, provided they are not enlarged in size or height and do not receive new windows on the wall nearest an abutting property. It allows the detached ADU without regard to setbacks or floor area under those conditions. It does not establish eligibility for every older garage.
2026 verification note: ZTA 26-06 proposes changes to ADU standards. The Council’s September 15, 2026 agenda scheduled action on the amendment. An agenda establishes the scheduled item, not the adopted text or effective date. I checked published Chapter 59, the DPS ADU presentation and the September 15 Council agenda on October 5, 2026. I did not verify a final adopted ZTA 26-06 text and effective date in those materials. The Council amendment index could not be retrieved during this check. Ask DPS which enacted provision it currently applies to your permit; do not treat either the older code text or an introduced proposal as confirmation of today’s ADU setback.
What to check before drawing your building location
- Identify zoning and the development method. Record the parcel address, zone and any applicable approval. A neighborhood name alone does not identify the right table.
- Use a boundary survey. Mark lot lines, streets and existing buildings. Do not rely solely on the visible fence as the boundary.
- Describe the actual use. Tell DPS whether this is storage, vehicle parking, an attached addition or a proposed dwelling, including any planned future conversion.
- Provide height and dimensions. Ask DPS to confirm how height, projections and the length along each lot line are measured for the plan.
- Check the rest of the site. Have the reviewer assess lot coverage, easements, utilities, access and any other site restrictions. Passing a setback check does not resolve the entire permit.
For a dwelling project, work through the ADU Feasibility Checker before requesting construction quotes. If you are converting an existing building, the garage-conversion guide explains the broader planning questions.
Basement, attached addition or detached garage conversion?
An interior or basement conversion within the existing house does not add a detached footprint to the backyard. Check any proposed exterior stairs, entrance, window wells or expansion separately. An attached addition needs the applicable principal-building placement review; do not use the shed table merely because the addition will contain an ADU. The attached and detached definitions in §59.3.3.3.B–C distinguish these uses.
For a detached garage, gather the original permit, evidence of its construction date and a current survey. The older-structure exception described above has specific conditions; an existing wall near the boundary is not proof that a new dwelling or a second story can use that location. Ask DPS to review any enlargement, height increase or new windows before designing around the exception.
Municipal boundaries, historic review and private restrictions
Rockville and Gaithersburg have independent zoning. Their own standards control rather than this County table. Montgomery Planning’s official municipal map layer places Takoma Park, Somerset and the Chevy Chase municipalities under M-NCPPC zoning. They should not be described as blanket exemptions from County zoning. Identify the exact municipality, then ask its permit office which additional municipal approvals apply. “Chevy Chase” in a postal address alone does not identify the reviewing municipality.
For a designated historic property or district, check Historic Area Work Permit requirements before new construction or exterior changes. Historic review is a separate approval question, not a universal extra setback number. Review the property’s recorded covenants and any HOA architectural requirements as well; the County’s accessory-structure permit guidance flags private deed restrictions and covenants.
Ask your surveyor to show recorded utility, sewer, drainage and access easements. A zoning setback is measured from a lot line; an easement has its own recorded limits and terms. Do not assume that satisfying the zoning distance gives permission to build across an easement.
Is there enough usable backyard space?
Site-plan preparation checklist
Tick these as you gather evidence. The checks are a planning record, not an eligibility decision.
If those answers are incomplete, use the ADU Feasibility Checker to prepare your next questions. A leftover rectangle on a sketch does not establish that an ADU can be permitted.
Setback questions that change a site plan
Can I apply for a setback variance?
Yes, there is a County variance process, but approval is not automatic. The Board of Appeals filing guide says to consult DPS about the precise relief needed and obtain the building-permit denial required for the application. The applicant must satisfy the standards in §59.7.3.2; needing more room for a preferred design is not an approval by itself. Use the Board’s current forms and filing instructions.
Do eaves, gutters and air-conditioning units count?
§59.4.1.7.B.5.a.vii allows eaves, cornices and light shelves to project up to 2½ feet into a setback, normally remaining at least two feet from the lot-line plane. The section has a separate lot-line-wall provision; ask DPS before using it. Subsection B.5.b.i allows residential mechanical equipment, including HVAC, to project up to five feet into front or rear setbacks. That text does not give the same general allowance for a side setback. Show gutters, equipment and overhangs on the plan and ask which specific exception applies.
How close can a detached ADU be to the main house?
The lot-line table does not establish a fire-code separation between two buildings. I did not find a single minimum that can be applied to every ADU configuration in the Chapter 59 sections and DPS ADU presentation reviewed October 5, 2026. Ask DPS’s building reviewer to evaluate the actual spacing, walls, openings, eaves and proposed construction. Do not label the green area in the diagram as an approved ADU envelope.
For the permit discussion, use the DPS zoning and permitting presentation for ADUs and DPS permit services. The presentation explains the earlier ADU framework; verify later amendments with staff. DHCA’s Class 3 ADU portal handles the licensing side, which is separate from building-plan approval.
Questions to ask Montgomery County DPS
Bring the survey and a simple dimensioned sketch. Ask: “Which accessory-structure or ADU provision applies to this address and use? Is this a standard-method lot? Which lines are treated as side, rear and side street? What adjustments apply to this height and length? Which enacted ADU amendment and effective date govern this application?” Request the code section supporting the answer.
DPS lists 311 within Montgomery County and 240-777-0311 from outside the County for shed setback information. For comparisons elsewhere, see our Maryland ADU setback guide.
Maryland ADU Guide is an independent research publication maintained by Gijo John. Send source-backed corrections to gijo.j@marylandaduguide.com.