Request to increase impervious cover for 12,000-square-foot home postponed by BoA

A couple building their dream home can find it disheartening to make it through the architectural design and site plan process, only to have an administrative hiccup put their plans on pause.

John and Amy Porter, who own 1704 and 1706 Channel Road, found themselves in this position when they came before the Board of Adjustment at its July 8 meeting. The Porters requested a variance to increase the maximum impervious coverage requirement from 35 percent to 38.5 percent on the 1704 portion of the site, which is zoned under Lake Austin zoning.

“The goal of this development project was to maximize the amount of impervious cover that I’m allowed to use on these two lots together,” John Porter explained.

To accomplish this goal, the couple originally applied for a Unified Development Agreement to combine the lots, and designed their home within the impervious cover limitations of the two combined properties. However, in the building plan review stage of the project, reviewers asked to examine the impervious cover of the two lots individually, not as a single unit.

As a unified lot, the nearly 12,000-square-foot home design would be 540 square feet under maximum impervious cover allowed. However, as stand-alone lots, 1706 is 1,349 square feet under the limit, while 1704 is 809 square feet over the limit.

Bruce Aupperle, who was representing the applicants on the project, explained that due to the lot at 1704 being subject to Lake Austin zoning regulations – which limit impervious cover to 35 percent in addition to having two sides with shoreline setback – it severely curtails the amount of impervious cover allowed on the lot. He acknowledged that the design could move some of its massing onto the 1706 side, but there are three protected pecan trees that the design currently avoids uprooting.

“To me, this seems like a self-imposed hardship because of the size of this building,” said Board Member Ada Corral. She noted that removing 800 square feet from the design would be doable and would allow the homeowners to develop their lot without a variance.

Board Member Don Leighton-Burwell said that although the idea to create a Unified Development Agreement was wise, there was little reason for the house to be built at such a scale. “This is a huge house. The first floor is 10 times the size of my house,” he observed.

Commisioner Melissa Hawthorne noted that in requesting to see impervious cover calculations for the individual lots, the calculation becomes difficult to compare. The lot with Lake Austin zoning uses net site area, which means that slope categories and water quality setbacks are subtracted from the total developable site area. The other lot, which has single-family zoning, uses gross site, which means the total square footage of the site.

However, in the variance application the lots are only calculated with their respective site area requirements, not both. Requesting a variance for impervious cover and using that comparison, said Hawthorne, is like comparing apples to oranges.

In order to get a clearer picture of how much impervious cover is on each lot and compare it across the same base, she made a motion to postpone the case until Aug. 12. The board voted 8-2 in favor of the postponement with Board members Darryl Pruett and William Burkhardt voting against the motion.

Other board members requested that the applicant return in August with a more persuasive hardship than having shoreline setbacks. “To me it only sounds like you want a symmetrical house and a very, very large house,” said Board Member Yasmine Smith. “And there are ways to do this with being in code.”

Map courtesy of the city of Austin.

The Austin Monitor’s work is made possible by donations from the community. Though our reporting covers donors from time to time, we are careful to keep business and editorial efforts separate while maintaining transparency. A complete list of donors is available here, and our code of ethics is explained here.