Guide to Washington, D.C. Zoning Code for Landscape Design (Part 1):

Setbacks, Yards, and Exceptions, or What You Can Build Where

So you live in Washington, DC and you want to make your yard more enjoyable and usable. You may be thinking of outdoor improvements such as a deck, screen porch, steps, fence, retaining wall, trash enclosure, bike storage,  patio, or shed. Because DC is a dense city, there are a lot of regulations that limit what and where you can build. The million-dollar question (sometimes literally!) in DC is this: Can you build it there? The goal of this article is to help you determine what you can build and where you can build it. You're in luck: I've never encountered a property where nothing could be done. If you don't live in DC, I plan to write similar guides for Montgomery County, MD and Prince George's County, MD soon. Section two of the guide, Lot Occupancy, Sheds, and What you Can Build in Required Yards, can be found here.

This article will be pretty technical, so buckle up! Remember that I'm always here to provide assistance; since I do this every day it's really easy for me to get a handle on the regulations that affect your property and start running through design possibilities. Please reach out to me at renee@sandboxlandstudio.com to set up a consult or inquire about a design.

For the purpose of this guide, I'll assume you're in a residential (R) or residential flat (RF) zone. R zones consist mostly of freestanding houses, while RF zones consist mostly of row houses. The code that discusses spatial regulations is called the Zoning Code. DC's most recent zoning code was passed in 2016. It is a living document that changes with time. As such, I will copy the text of the code (in case links move around) and also link to the code (in case the text is out of date). The information in this article should be accurate as of January 2025. Make sure to confirm and/or clarify the code before making any decisions based on this information! Please reach out to me at the above email address if you discover the information is no longer correct or if links have broken.

Which Residential Zone Are You In?

What you can build may depend on where in the city your house is located. Different parts of Washington, DC have different zoning regulations. To look up the zoning for your house, use the interactive DC Zoning Map. Type in your address and scroll down on the left sidebar to the box that says 'Zoning/Land Use'. You will see a code with a R, like R-2. Click on this link, and on the subsequent page, click on the button that says "See (your zone) Development Standards." The development standards page is a great snapshot of your property including setbacks, lot occupancy, and pervious surface requirements­—all things we'll be talking about in a bit, so keep the page open or take a screenshot.

DC Zoning Map Screenshots
DC's online zoning map with a rowhouse parcel highlighted and a link to information about the zone district and zoning code for the property

Once you've located your property by typing in your address, click on the name of the zone below 'Zone District' on the left sidebar. Here it says R-2.

Example of DC's development standards for Zone R-2

After clicking through 'See (your zone) Development Standards', you'll see a table of zoning information related to your property. This is really useful!

Defining Terms

Before we get into more detail, we need to define some terms because things are not always as they seem. You can find the full list of definitions at 11-B100 in the code , which can be downloaded and searched. Keep this document open, because we'll need it again.

What Does DC Consider a Structure?

Structure:  Anything constructed, including a building, the use of which requires permanent location on the ground, or anything attached to something having a permanent location on the ground and including, among other things, radio or television towers, reviewing stands, platforms, flag poles, tanks, bins, gas holders, chimneys, bridges, and retaining walls. The term structure shall not include mechanical equipment, but shall include the supports for mechanical equipment...

Clear as mud, right? I generally think of a structure as anything that is permanently attached to and sticks up from the ground (a fence, a building, a deck, something extending from a building) or holds back soil (a retaining wall). If it's overhead (a pergola, a carport, a shade sail), it's a structure. If it needs to be engineered, it's a structure.  If it's flat on the ground like a patio, it's not considered a structure. Planting beds are not structures, nor are stepping stones or parking pads.

How Does DC Define a Yard?

Yard: An exterior space, other than a court, on the same lot with a building or other structure. A yard required by the provisions of this title shall be open to the sky from the ground up, and shall not be occupied by any building or structure, except as specifically provided in this title. No building or structure shall occupy in excess of fifty percent (50%) of a yard required by this title.

Courts are a special type of yard that I rarely run into; I wouldn't worry about them unless you have a semi-enclosed courtyard situation. In that case, take a look at the definition of 'court' on the definitions page and in section 11-B321.

To clarify the above definition, note that the code is making a distinction between a yard and a required yard:

  • A yard is the total exterior space around a building or structure and inside the property line. This includes both required yards and any additional yard space not required by the city. This is how most people commonly think of their yards.
  • Required yards are the portions of yard around the edges of a property that the city has decided should remain open for health, safety, and sunlight/ventilation reasons. Required yards may usually contain things flat to the ground like patios and parking areas, and vegetation including trees. We'll learn about the dimensional standards for required yards in just a bit.

Note the requirement that "no structure shall occupy in excess of fifty percent (50%) of a yard required by this title." At first glance, this seems contradictory. If a yard shall not be occupied by any building or structure, how could half of it be occupied by a building or structure?? The key is in the phrase 'except as specifically provided in this title.' As we'll see in the next article in this series, there are some exceptions to the rule, which become quite important in landscape design.

Which Yard is the Front? Side? Rear?

According to the definitions document, DC defines front, side, and rear yard as follows:

Front Yard: "A yard between the front facade of a building and the front lot line. The front yard when required, shall extend for the full width of the front of the lot."

Side Yard: "A yard between any portion of a building or other structure and the adjacent side lot line, extending for the full depth of the building or structure"

Rear Yard: "A yard between the rear line of a building or other structure and the rear lot line, except as provided elsewhere in this title. The rear yard shall be for the full width of the lot and shall be unoccupied, except as specifically authorized in this title."

Note that while front yards and rear yards extend the full width of the lot, the side yard only extends as far as the building or structure. This is different from almost every jurisdiction I've worked in! I just got off a call with a very nice zoning technician from the Office of Zoning Administration in DC's Department of Buildings who confirmed this and also answered a few other questions.

The zoning tech said that, unlike other jurisdictions, DC doesn't have a guidance document specifically for irregular lots, so reach out to them if you have any questions about which is your front, side, and rear yard. He noted that there are some weird lots in DC and it's often based on what is most in compliance with the existing zoning. Every time I've had to reach out to the City I've had a response within a few days. They really do want to help you if you're asking good-faith questions to try to understand and comply with zoning.

Required Yard or Setback?

Note that a required yard is not (quite) the same as a setback, although even DC sometimes uses the terms interchangeably, as in the development standards web page shown above. DC seems to be moving away from using the term setbacks in official language except in front of the house. Setbacks specify the required distance a structure should be 'set back' from the property boundary. The setbacks for a principal structure (your house) are different from the setbacks for an accessory dwelling unit, garage, or shed. If two setbacks are in conflict, the most stringent applies. Here is the only remaining definition related to setbacks:

Setback, Front: A distance required between a building and a street lot line, and measured from the street lot line inward to the lot.

Requirements for Front, Rear, and Side Yards

Depending on what zone you're in, you may be required to have a  setback or yard of a certain size. This will limit where you're allowed to build "structures". But don't despair- there are a number of exceptions, so keep reading!

The development standards for residential (R) and residential flat (RF) zones are in two slightly different locations online, but the actual code numbers and text are mostly the same. Here are the links to the residential zone standards at 11-D2 and residential flat zone standards at 11-E2. The following text is excerpted from the code. If the information was not relevant to this article, I didn't copy it. I would always recommend clicking through to read the full text in case it applies to you! If you're unsure about how to measure yards or setbacks, the section 11-B3 General Rules of Measurement provides guidance, so take a look at the applicable subsections.

Front Setback
206.2 For all residential buildings, a front setback shall be provided within the range of existing front setbacks of all residential buildings on the same side of the street in the block where the building is proposed.
Side Yards
208.1 Except as provided elsewhere in this title, the minimum side yard requirements shall be as set forth in this section.
208.2 Two (2) side yards, each a minimum of eight feet (8 ft.) in width, shall be provided for all detached buildings.
208.3 In any of the R-2 zones, one (1) side yard, a minimum of eight feet (8 ft.) in width, shall be provided for all semi-detached buildings.
208.4 In any of the R-3 zones, one (1) side yard, a minimum of five feet (5 ft.) in width, shall be provided for all semi-detached buildings.
208.5 No side yards are required for row buildings. An existing detached or semi-detached building shall not be treated as a row building through construction or additions.
208.6 Existing conforming side yards shall not be reduced to a non-conforming width or eliminated.
208.7 In the case of a building with a non-conforming side yard, an extension or addition may be made to the building; provided, that the width of the existing side yard shall not be reduced or eliminated; and provided further, that the width of the side yard adjacent to the extension or addition shall be a minimum of five feet (5 ft.).

The rear yard is the one case where the text between R and RF zones is slightly different, despite the code number and the surrounding text remaining identical.

Rear Yard
207.1 Except as provided elsewhere in this title, the minimum required rear yard shall be as set forth in the following table:
Minimum rear yard table for Washington DC's RF zonesMinimum rear yard table for Washington DC R zones

DC's Mysterious "Public Parking" Areas

Unlike many other municipalities, DC doesn't define corner lots as having two front yards. Instead, they regulate something else that I just learned about: Public Parking. Now, you won't find this term in the definitions list, and it doesn't have anything to do with parking a car. It goes way back to 1870 when DC wanted to increase the amount of green (park) space and passed a law called the Parking Act. Basically, they decided to make the street right-of-way much wider than the pavement itself so that the streets could be lined with "parks." Then they made the maintenance of these parks the responsibility of the adjoining property owner. Many people think their property extends all the way to the sidewalk or street, but in reality it rarely does.

In many areas with older row houses, this public "parking" area stretches all or most of the way to the house. In 1871, the "Projection Act" allowed porches, bay windows, and corner towers to project into this public space. So in many areas, the entire "front yard" is really a park owned by the city, maintained by the homeowner, normally treated as private property, and subject to special regulations. Your front porch may even be located on public space, but you still have to maintain it. In the case of a corner house, part of the side yard may also be a parking area and subject to the same regulations. Parking Area regulations cover hedges, fence height, walls, grading, and paving. I may write an article on this specifically but for now, know that most activity in the public space requires an additional permit. The relevant codes are at 24-102 through 24-104 (the three sections labeled "public parking").

Here are some more articles discussing DC's "Public Parking"
Forest Hills Connection 'The City Park Outside Your Front Door'
Mount Pleasant's spacious yards, and "public space"

Map of Public Parking Areas
Graphic showing private property and DC's Public Parking Areas

In this graphic from the DC zoning map, gray is private property, white are streets, and pink is "public parking". You can see that the corner lots have public parking on two sides. There is no public parking along alleys.

Aerial Image of the Same Block
Aerial image showing Public Parking areas in DC

As you can see from this aerial image, there's no indication on the ground that part of the yard is technically public property! Most residents think their property begins at the street or sidewalk, which is often untrue.

Text of Washington DC's 1870 Parking Act
Original text of DC's 1870 Parking Act

Combining What We've Learned So Far: An Example

So far we've learned about structures; front, rear, and side yards; setbacks; and public parking. When I'm doing a design for a client I'll combine these into a single graphic so it's really easy to see the opportunities and constraints at a glance. I don't always show it to the client, but it always informs my design work. This is not the end of the process, but it's a good stopping point. There are many exceptions to the rules, which we'll cover in the next article, but it's always good to know the general rule before getting into exceptions.

Each of these row houses is in zone R-2. Interior row houses have no required side yards, but end units (because they are 'semi-detached') have 8' required side yards (in blue). All row houses in this zone have a 20' required rear yard, in red. The existing front building line is at the face of the rowhouses and the front setback is shown in orange. All of the green is "public parking", technically owned by the city, but maintained by homeowners. Note that the row house on the corner has public parking on two sides of the lot . The white area in the graphic is where  structures may be located so long as all other requirements such as lot coverage, pervious surfaces, and other setbacks are met. I don't usually deal with additions as I'm not an architect, but note that rowhouses are only allowed to project up to 10' beyond their neighbors.

Other areas of the city with different densities may have very different proportions of public space, buildable area, and setbacks, so don't be surprised if your graphic is very different!

Rowhouses in R2 zone in Washington DC showing required side and rear yards, front setback, and public parking

This post got out of hand and is continued in Part 2: Lot Occupancy, Sheds, and What you Can Build in Required Yards. Keep reading for exceptions to the rules about what you can build in required yards, lot coverage requirements, and—very important—shed size and location!

And remember, you can always reach out to me for help at renee@sandboxlandstudio.com. I'd love to set up a quick chat to discuss how I can help you improve your outdoor space!
Renee