Mapping CodeNEXT: Units and Height

Austin’s proposed land use code rewrite would line major city corridors with narrow strips of dense, mixed-use development zoning. But just behind those ribbons of mixed-use street design, vast swaths of Central Austin neighborhoods would remain much less dense.

These two effects are brought into stark light by two new interactive maps produced for the Austin Monitor that visualize how the second draft of CodeNEXT would shape future development.

The first map, below, colors the city in various shades of red to chart the maximum number of residential dwelling units allowed per lot, acre or building. The darker the color, the more units allowed per building. Clicking a shaded block within the map brings up an infobox breaking down the residential dwelling unit regulations.

For an expanded version of this map, click here.

The second map, at the bottom of this article, colors the city in various shades of blue to chart the maximum allowable heights permitted under CodeNEXT’s second draft. Likewise, the darker the shade, the greater the allowable height. Clicking a shaded block within the map brings up an infobox focused on height regulations.

As you can see, and as to be expected, downtown is the focus of the densest allowable residential development and building massing. Here, most of the zoning is split between new high-intensity zoning categories such as Commercial Center and Downtown Core that are explicitly designed to produce mixed-use environments. Developers here will have no dwelling unit restrictions, but their buildings must meet other zoning requirements.

But spreading out from downtown are thin curtains of dense, mixed-use zoning that almost form a wall hiding neighborhoods designed for detached housing. Consider the East Cesar Chavez Street corridor. As it stretches east from Interstate 35, CodeNEXT calls for Main Street 2B zoning, which allows “multi-unit residential, office, service and a broad array of retail uses in attached block-scale buildings.” In hard numbers, that zoning designation allows up to three dwelling units per acre for medium-sized rowhouse-style buildings, and has no upper dwelling unit limit defined for block-form building types.

But if you travel half a block south from East Cesar Chavez Street, the zoning quickly downshifts into the Residential House-Scale, or R3C, category. It’s a zone designed for detached housing, but also allows duplexes and accessory dwelling units. With the exception of those accessory dwelling units, it’s a lot like what’s there already, and it’s a pattern repeated throughout the central core of the city: suburban-esque interior neighborhoods walled by rings of denser development, with dramatic transitions between allowable residential uses and height.

It is with accessory dwelling units that CodeNEXT could make its biggest impact on Austin neighborhoods, according to the data. The proposed code calls for a dramatic expansion in the number of parcels and lots zoned to allow these small secondary dwelling units, often dubbed “granny flats.” In all, more than 11,130 zoned blocks would now explicitly be allowed to build at least one accessory dwelling unit per lot or building, depending on the building type. Only 6,330 zoned blocks, many of them downtown areas featuring high-intensity uses, do not allow accessory dwelling units. Current zoning, which only allows accessory dwelling units on lots zoned Single-Family 3 and Single-Family 2, a suburban-style detached housing similar to CodeNEXT’s R3C zone that covers – at maximum – about 8,600 blocks.

Further, CodeNEXT proposes to allow accessory dwelling units in many medium-intensity multifamily and mixed-use zones that would line the city’s major corridors. Today, while many are undergoing rapid changes, vast stretches of these corridors are dominated by asphalt-fronted, single-story strip-retail development. Consider Far West Boulevard in Northwest Austin. On the northern side of Far West, where there is currently a three-block-long strip of unassuming yellow-brick, single-story retail development, CodeNEXT would permit a base standard of “medium-intensity” mixed-use development under the Mixed-Use 3A zone that permits up to 36 units per acre. If the development qualifies for the affordable housing bonus program, an additional 18 units per acre are allowed.

Also worth noting, vast stretches of Tarrytown and West Austin would remain, effectively, as they look today. Exposition Boulevard, West Austin’s main north-south surface-street corridor, is mostly zoned at R3C and R2C, two relatively spread-out suburban-esque zones with max heights of 32 feet.

For an expanded version of this map, click here.

These maps do have limitations. Most pressingly, they do not accurately portray height and dwelling unit regulations in areas of the city where special zoning designations, such as planned unit developments, corridor overlays and Neighborhood Conservation Combining Districts, are being carried forward in some manner. Due to the nature of the data available from the city in version 2 of CodeNEXT, these zones are labeled simply Former Title 25, or F25 zones. On the map, they are shaded according to the citywide average maximum values for allowable height or dwelling units, respectively. City officials plan to more fully detail their plans for these zones in the next major CodeNEXT revision.

And, of course, these maps reflect the highest potential use of the newly proposed zoning, not what is guaranteed to be built along the city’s corridors and in its neighborhoods. That, as with any land development code, will be determined by a number of factors outside of the scope of zoning.

Curious about how we got here? Check out the Austin Monitor’s CodeNEXT Timeline.

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