Residential Setback Requirements

The distance from any proposed addition to the property lines is regulated by the minimum yard requirements (setback requirements) set forth in the zoning district regulations in the Zoning Ordinance. Each zoning district has unique minimum required yards and the answer depends on the zoning district in which your property is located. The construction of a deck is also regulated by the minimum yard requirements, but, depending on the height and features of the proposed deck, it may be permitted to extend into the minimum required yards. You will need to contact the Zoning Permits Branch of the Department of Planning and Development at 703-222-1082, TTY 711 to discuss location restrictions on your property.

The county's Zoning Ordinance regulates the location of fences and walls on a lot based on the height of the fence or wall. On most residential lots, the Zoning Ordinance only allows a fence or wall of 4 feet or less in the front yard. Remember that on corner lots, the two yards which lie between the principle building and the intersecting streets are both deemed to be front yards. In a side or rear yard, a fence or wall of not more than 7 feet is generally allowed. There are some limited exceptions to these rules for particular types of lots that abut or are in close proximity to major thoroughfares. For specific information regarding your property and designation of the yards on your lot, please contact the Zoning Permits Branch of the Department of Planning and Development at 703-222-1082, TTY 711. In many instances, a Building Permit is not required for a fence. For information regarding building permit requirements, please contact the Permit Application Center of Land Development Services at 703-222-0801, TTY 711.

The county regulates the location of all free-standing accessory structures and, in most instances, also requires the approval of a building permit prior to the errection of any structures. Article 10-104 of the Zoning Ordinance regulates the location and permitted height of accessory structures and uses.

No accessory structure or use, except a statue, basketball standard or flagpole, shall be located (a) in any minimum required front yard on any lot or (b) in any front yard on any lot containing 36,000 square feet or less. When located in a front yard, basketball standards shall not be located closer than fifteen feet to a front lot line or twelve feet to a side lot line, and shall not be used between the hours of 8 p.m. and 8 a.m.

Generally the following rules apply to the location of accessory structures:

• An accessory structure or use that does not exceed 7 feet in height may be located anywhere in a side or rear yard. Any accessory structure or use that exceeds 7 feet in height shall meet the minimum required side yard setbacks, and shall be located no closer than a distance equal to its height to the rear lot line.
• A shed that is 8 ½ feet or less in total height may be located anywhere in a side or rear yard. Any shed that exceeds 8 ½ feet in height shall meet the minimum required side yard setbacks, and shall be located no closer than a distance equal to its height to the rear lot line.

The total height of the accessory structure is measured from grade to the highest point of the structure. In instances where there is a slope in grade height is measured from the lowest point of the slope.

These regulations apply regardless of whether or not a building permit is required. If county easements are present on a lot, no structures shall encroach into the ground or air space of the easement. Before locating a shed on your property, please contact the Zoning Permits Branch of the Department of Planning and Development at 703-222-1082, TTY 711. Building permits may be required for sheds and other free-standing accessory structures depending on the size. Please contact the Permit Application Center of Land Development Services at 703-222-0801, TTY 711, or view the Additions and Garages page.

Under the Zoning Ordinance, a tree house is an accessory structure and subject to the following regulations:

• A tree house up to seven feet in height (1) is not permitted in any part of a front yard on a lot containing 36,000 sq. ft. or less, or in any required front yard setback on a lot containing more than 36.000 sq. ft.; and (2) is permitted in any part of a side or rear yard.
• If the tree house exceeds seven feet in height, it must be setback at a distance equal to its height from the rear lot line and a distance equal to the side yard setback from the side lot line.
• (As an example, a 15-foot tall tree house that’s located on a property with a 12-foot minimum required side yard must be setback at least 15 feet from the rear lot line and at least 12 feet from the side lot line.)  
• The height of the tree house is measured from the highest point of the house to the lowest point of the finished ground adjacent to the tree house.
• Building permits are required for tree houses greater than 256 sq. ft. in size. 

For information on permitted extensions into setbacks, please refer to Article 2-412 of the Zoning Ordinance.