Experts say that changes to subdivision rules are necessary for Austin's ambitious affordable housing initiative to succeed.

Austin has implemented big changes to housing development rules through its HOME Initiative, but experts say more tweaks are needed at city hall if the potentially city-altering plan is to work well. With a goal of taming rising home prices, Austin has OK'd two phases through its HOME Initiative, which stands for the Home Options for Middle-income Empowerment. The first phase was passed in December and allowed for three homes to be built on a single-family lot. The second phase, which drastically reduced minimum lot sizes to 1,800 square feet, was implemented on Aug. 16.

HOME offers "that variety of housing that Austin very much needs for its teachers, its first responders," said Taylor Jackson, the CEO of Home Builders Association of Greater Austin. But, as she and others point out, it won't do much if the process to add the homes is too expensive or cumbersome. "Taking a 6,000-square-foot lot, you could theoretically divide it into three units, but it's not going to make sense to spend $100,000 in a year to do that," said Brita Wallace, a board member of the Austin Infill Coalition, an organization that strives for more housing options.

Currently, the subdivision process doesn't substantially differentiate between large or small housing projects, Wallace said, and it can cost over $100,000 and take several months or even years to subdivide residential property, which would need to be done if a homeowner or developer wants to sell a chunk of a single-family lot.

Without changes to the subdivision process, Wallace doesn't expect the changes in HOME Phase 2 to be used by homebuilders, and it's likely more projects will be built under HOME Phase 1 changes. That basically entails one landowner renting out any new homes built on a site. Phase 1 also allows developers and homebuilders to seek approval through the city's general residential review process instead of the more expensive and time-consuming site plan review process. As of Aug. 21, Austin's website shows 173 applications that propose to build 324 units have been submitted to the city under HOME Phase 1, and 112 of those applications were approved.

Changes to the subdivision process could be on the horizon as Austin's website said the city council should consider changes to its subdivision rules sometime in September to "better accommodate small lot single-family development."

But it's not clear what those exact changes will be or if the city council will approve them.

Jackson said the city of Austin has been a good partner with homebuilders on working on issues to remove affordable homebuilding barriers, and she hopes changes to subdivision rules are made soon so they can be paired with HOME Phase 2.

HOME Phase 2 "truly has the potential of being very effective if we can work through that subdivision process... it will just really unleash a lot of that missing middle housing," said Jackson.