Austin HOME Initiative: New ADU Rules Explained (2025)

The HOME Initiative Has Changed Everything

In a major push to address housing affordability, the Austin City Council passed the HOME (Housing Options for Middle-Income Empowerment) Initiative. For homeowners, this is the biggest zoning change in decades.

Key Changes for ADUs

1. Three Units Per Lot

Previously, most single-family lots were limited to a house plus one ADU. Now, under Phase 1 & 2 of HOME, many lots can have up to three dwelling units. This could be a main house and two ADUs, or a triplex configuration.

2. No More Parking Mandates

One of the biggest hurdles to building an ADU was finding space for a paved parking spot. The new rules eliminate parking requirements for ADUs citywide. You can still build a driveway if you want, but the city won't force you to pave over your yard.

3. Size & Height Limits Relaxed

ADUs can now be two stories tall (up to 30-35 feet depending on zoning), allowing for "garage apartments" or 2-story cottages that preserve more backyard space.

What About "Impervious Cover"?

While density limits have relaxed, drainage rules haven't. You generally still need to keep impervious cover (buildings + concrete) under 45% of your total lot area. This is often the real constraint on how much you can build.

Who Benefits Most?

Homeowners with large lots (over 7,000 sq ft) or deep backyards stand to gain the most. The ability to add a second or third unit creates massive equity and rental potential.