Every time I post on the Vertical Mixed Use ordinance, one of the commenters asks me what it is and why it's a good thing. Here's a very short VMU primer.
For reasons that I still do not understand, residential development is forbidden on commercially-zoned tracts. Since most properties lining busy streets are (understandably) zoned for commercial uses, there are few places on these streets to add new housing. But it is difficult to add multi-family residential in neighborhood interiors -- neighborhoods fight it tooth and claw. This leaves little room for new multi-family, at least without a zoning fight.
VMU zoning is supposed to fix that. The "VMU" designation permits residential development on commercially-zoned tracts on "core transit corridors" (major streets like Lamar and Riverside), unless they have been specifically opted out. The VMU ordinance promises to open up thousands of new tracts for residential development.
VMU comes with strings attached: the residential must be bundled with ground-floor commercial or office uses (whence "mixed use"), and the development must meet stringent design standards. (The ordinance even specifies minutiae like glass height and tinting in excruciating detail.) VMU projects remain subject to compatibility (height), impervious coverage, floor-to-area ("FAR") and density limitations (where applicable). However, FAR and density limitations are waived for developments that reserve 10% of the units for affordable housing. (A density limitation -- "minimum site area requirement," in code lingo -- is an anachronistic suburban-style zoning tool that limits the number of units per acre, regardless of the allowable height, lot coverage, or floor-to-area ratio.)
The waiver of FAR limits is important. For example, the FAR limit for a CS (general commercial) lot is 2. This means a half-acre lot can hold a 43,560 square foot building. That might sound like a lot, but that's just a three-story building, assuming development to the minimum setbacks. The height limit might permit six stories, though, which means the FAR restriction chops the buildable area in half. Waiving the FAR limit might give the development 25%-100% more space. (Density limits are even more draconian when they apply.)
Neighborhoods get a say in the process. They get to set the level of affordability necessary for the FAR/density waivers -- e.g., 60% or 80% of median family income. Or they can opt out of the relaxed dimensional requirements completely. They can relax the minimum parking requirements. And they have the option of opting in properties that were not originally zoned VMU.
As originally drafted, the VMU ordinance did not permit neighborhoods to opt properties out of VMU altogether. That was one of the ordinances' strongest features: it eliminated the contentious property-by-property haggling that marks Austin's land-use regulation. However, in February 2007, Council amended the VMU ordinance to permit neighborhoods to recommend that specific properties be opted out of the VMU district. Some neighborhoods, predictably, now want to scale back VMU zoning.
Council began considering neighborhood applications in November 2007. Since 40 or so neighborhoods filed applications, the process will drag on into the spring of 2008. By the time it's done, though, there should be a lot more room for residential development in central Austin.