Deed restrictions are a huge constraints. There are entire neighborhoods where duplexes are prohibited by deed restrictions even though allowed by zoning. It's important that any zoning capacity analysis take these constraints into account, otherwise we will undershoot the housing target.

Austin History Center on Guadalupe.

I doubt that was the intent. But maybe they did mean that. I went back over the ADU standards and they don't say they're limited to being accessories to single family residences only.

Tom, (1) With regard to your neighborhood specifically -- and many, many others -- this is an academic exercise, as I'm pretty sure the homes in your neighborhood are deed-restricted to single-family homes. (If they weren't, you'd see a lot of duplexes being built over there, and you don't). Feel free to correct me if I'm wrong about this. The same will be the case in many (most?) of the drivable areas built from 1960s on: CC&Rs limit the lots to one single-family home. Zoning is irrelevant in much of the city. (2) Let me turn this around: Where does IA say that you can't lower the minimum lot size for duplexes? Or permit an ADU and duplex on the same lot? Both of those are "relaxing" SF-3 standards. Page 107 of IA does not say you cannot relax SF-3 standards. I'd submit that all of these are consistent with IA. (3) I also think there are neighborhoods in the city where 4-plexes are consistent either with historical development patterns or with the goal of "serv[ing] neighborhood needs and creat[ing] complete communities." (p. 107). At the very least, there are transition zones between commercial corridors and neighborhood interiors where these are appropriate. (As far as I can recall, none of the medium R zones allow zero lot lines.)

I've been assuming that they will work the reduction in with the density bonus section, but that may be unwarranted.

Ron, are you suggesting that the director could require a fee in lieu in order to take advantage of the reductions along transit corridors? If not, then I don't see how a fee in lieu makes things worse as long as it's just an additional option. Developers can always fall back on the legislated minimums, which are better than today's.

Any change to the gross floor area IS huge and I need to address it. If they stick with the definition of "gross floor area" in the definition section of 23-2, then you are right. Enclosed garages will no longer be exempt at all from the FAR limit. That would be a large reduction in buildable space. On the other hand, I don't read the definition to count open carports or front porches as gross floor area.

Each of the lots has to be at least 3,000 sf, but they have to add up to 7,000 sf.The owners of a condo regime can always (if unanimous) dissolve the condo regime. I'd suggest verifying the subdivision requirements first!

Or handle using conditional overlays, which is exactly what they have said needs to be pruned from the code.

To expand, in T4N.SS, a multi-plex (MP) must have 3-8 units. This implies you can't build a duplex and call it a MP. A MP in T4N.IS isn't limited to 3-4 units. So maybe a two-unit MP is allowed. On the other hand, a front-and-back duplex is not allowed. So maybe you can build a two-unit MP as long as it is not a front-and-back duplex. These ambiguities illustrate why the form-based code will be hard to administer.

It's not clear that you can build a 2-unit multi-plex.

These are all fair questions. I don't know the answers. My guess is that they are trying to regulate the internal layout of the duplex; it's not just an envelope regulation. That will generate all sorts of complicated code interpretations as builders present creative layouts. On the other hand, I suspect the categories for single-family homes will be conjunctive rather than disjunctive. That is, if you build a house that falls within the small house, wide house and long house footprints, it qualifies as all of them.