Frederick County Shed Setback Requirements: Placement, Size & Permits

Reviewed October 5, 2026 • Ordinary sheds and detached garages • County zoning outside incorporated municipalities

For an ordinary detached shed on a property governed by Frederick County zoning, start with 6 feet from every lot line and 6 feet from any other building on the lot. Then check the required front yard, accessory-building size limit and permit route before paying a delivery deposit.

Frederick shed rules at a glance

Measure the shed location before choosing its size

A fence is a useful visual reference, but your plan needs the actual property boundary. Use a survey or recorded plat to identify the line, then draw the proposed shed and every existing building. A location six feet from the rear line can still fail the separate six-foot building-clearance requirement.

If your design shares a wall with the dwelling, use the county’s main-building classification rather than treating it as an ordinary detached shed. For a corner lot, irregular boundary or proposed front-yard location, ask zoning staff to mark the applicable yards on your sketch.

Record walls and roof edges separately

On your sketch, label both the wall footprint and the outer roof/eave dimensions supplied by the manufacturer. §1-19-6.150 addresses architectural projections into required yards. Ask zoning how it applies to the proposed accessory building; do not subtract a projection allowance automatically from the six-foot accessory clearance.

For the front yard, use the applicable district design requirements and have staff confirm any lot-specific modification. The six-foot accessory rule does not replace the required front yard. For height measurement, use the county’s building-height worksheet.

Two size limits that are easy to confuse

On residentially zoned property, the house’s footprint and its total floor area are different measurements. A two-story house may have a 1,000-square-foot footprint and 2,000 square feet of floor area. Under the ordinary footprint formula, half of 1,000 is 500, so the larger 600-square-foot allowance controls. Using half of 2,000 would overstate that footprint allowance.

For a house with a 1,800-square-foot footprint, half is 900 square feet. Separately, the total floor area of all floors of an accessory structure cannot exceed the dwelling’s total floor area. For a two-level accessory building, count both levels; the footprint calculation alone is not enough.

§1-19-8.240 also provides an R1 exception: on an R1 lot of at least 20,000 square feet, one accessory structure may exceed the ordinary footprint cap, up to 2,000 square feet. Do not assume this applies to another zone or removes the other limits. Accessory height is generally capped at 70% of the maximum height allowed for the principal permitted use—not 70% of the existing house’s actual height.

Check the ordinary footprint formula

How to establish the house footprint

Use an existing approved plan, a survey showing the building, or measured exterior ground-level dimensions. Split an irregular house into rectangles and add their areas. Record attached garages, porches and other projections separately so zoning can confirm which portions belong in the principal-dwelling footprint. An assessor’s living-area figure may include multiple stories and is not automatically the footprint.

Example: a 25 × 40 ground-level rectangle has a 1,000-square-foot footprint. Two full stories may total 2,000 square feet, but the ordinary accessory footprint calculation still starts with 1,000.

Does a 10 × 15 shed need a Frederick County permit?

A 10 × 14 shed is 140 square feet; a 10 × 15 shed is exactly 150; a 12 × 16 shed is 192. That middle size deserves a call before purchase.

The adopted residential-code amendment, R105.2 exempts qualifying one-story detached tool/storage sheds and similar uses with floor area not exceeding 150 square feet. The county FAQ instead tells owners that sheds 150 square feet or larger require a building permit. Because those statements differ at the boundary, confirm an exactly 150-square-foot shed with the permit office at 301-600-2313, option 4. Provide the manufacturer’s measured floor area, use and number of stories.

Below the threshold, check whether a zoning certificate is needed. New electrical work has its own permit requirements. A storage-shed exemption does not authorize sleeping accommodation or a separate dwelling.

Well and septic areas can decide the location

The Frederick County Health Department prohibits accessory structures over designated septic areas and principal septic components. Its guidance requires foundations to be at least 30 feet from a well unless a health variance is granted. An accessory structure with a basement must also maintain the stated 10-foot separation from the septic tank, leaching area and septic area. Ask Health to confirm how your proposed foundation and shed are classified.

Show the approved septic reserve area, not just the visible tank lid. A clear patch of lawn may be reserved for future wastewater treatment. Contact Health at 301-600-1726 before locking in a pad location.

Before you order or schedule delivery

Corner lots, roof edges and private restrictions

A street-facing lot edge may require front-yard treatment. Have zoning identify the required front yard on both road edges before using the ordinary six-foot accessory rule. The district table alone does not establish the classification of an unusual lot. Source: Frederick yard definitions.

Record the wall and roof-edge distances separately on the site sketch. A roof overhang, gutter, access ramp or mechanical unit may need a different projection or building-code check. Ask staff which edge controls the measurement; do not treat the calculator’s wall-distance result as clearance for every projection.

If the property has an HOA or recorded covenants, obtain the shed placement, height, appearance and approval requirements before ordering. County permission does not establish compliance with those private restrictions.

From a proposed location to the right application

1. Confirm the review authority. Identify county or municipal zoning and the building-permit office.
2. Prepare the parcel sketch. Show the shed model, wall/roof dimensions, boundary distances, other buildings, easements and well/septic features.
3. Resolve the permit route. Describe the story count, intended use and floor area; get an explicit answer for a 150-square-foot model.
4. Submit the required application. Use the county portal if the county handles the application. Arrange trade permits and inspection requirements with the permit office before construction.

For a garage, identify vehicle storage rather than describing it as a tool shed. Ask the permit office to confirm the garage drawings, foundation, fire separation and fee classification. The small storage-shed exemption is not a blanket exemption for every detached building.

Frederick shed planning worksheet

A question you can adapt for the county

Replace the bracketed details with your actual proposal. This page does not send messages to the county.

Questions homeowners ask

Official sources and your next step