After years of delays and extensive public input, DC’s zoning board approved a new zoning code in January. It will actually take effect in September. This map helps homeowners understand how the new zoning applies to them.

The zoning update includes some key steps forward, like allowing some homeowners to rent out garages or basements where it’s illegal today.

Otherwise, unless you live downtown, nothing dramatic will change. The zoning update generally doesn’t change the density and form someone can build in your neighborhood. Most specific rules, like how big and what shape a “court” can be, also don’t change, and you’re not expected to know them all unless you’re an architect or land use attorney.

But what does it mean?

The reason so little seems to be changing is because the zoning code basically consists of three parts: an administrative framework, rules for development in general, and land use rules specific to each zone district.

Most of the rewrite was reorganizing existing rules written in 1958 and patched several times over the years. That means updating the language, addressing new uses, and closing loopholes. Sure, there are some big controversial city-wide changes like permitting granny cottages in single family residential areas and reducing parking minimums.

What will likely change is the name of the zone you live in. In the old code, most zones were R (Residential) or C (Commercial); now, residential zones include the old R, RF (for residential flats, like row houses), and RA (for apartments); many commercial zones, which have long allowed residential and commercial together, are called MU (mixed-use), or D for downtown zones, and so on.

This table shows how the existing zone districts fit into the new zones. The interactive map (image at the top of the post) lets you compare old and new zoning side by side.

There are a lot more zone districts now — sort of. Some neighborhoods (like Cleveland Park) have “overlays” that customize their zones. Many changed the underlying zoning dramatically, which wasn’t readily understandable without flipping back and forth between sections.

In the new code, instead of overlays, there is just a new basic zone with all the rules from the underlying zone or the overlay. For example, the old R-1-B zone with the Foxhall and Tree and Slope overlay (for areas near the Potomac river on the west side of DC) will be R-9. The R-1-B zone with Naval Observatory overlay will be R-12.

The actual effect of the overlays remains, but you don’t have to reconcile two totally different sections of zoning code to figure out what’s going on. I think it’s a lot simpler to understand, whether you’re designing a building or imagining what your neighborhood could look like.

Neil Flanagan grew up in Ward 3 before graduating from the Yale School of Architecture. He is pursuing an architecture license. He really likes walking around and looking at stuff.