The Marin County Planning Commission sided with a San Geronimo Valley landowner last month in his quest to secure approval for a 93-square-foot addition to a second unit—despite the county staff’s argument that the addition is illegal. Commissioners unanimously ruled in favor of owner Dylan Arroyo, swayed more by personal pleas to keep the home—occupied by his father-in-law, Paul Sanner—intact than by strict interpretations of code. 

The commission’s ruling leaves the Community Development Agency in a bit of a quandary, said Tom Lai, the agency’s assistant director, who struggled to articulate the commission’s decision. For now, he said, the county’s legal team is assessing “how to legally issue a permit when—how shall I say this? In the case where the commission’s action does not comport with the code.” 

The agency’s role, he added, is to defend the decisions of the planning commission and the Board of Supervisors. But he has no idea what will happen if the county counsel cannot find a way to issue a permit. “I’m not aware of another situation like this. There’s no precedent I can think of,” he said.

Mr. Arroyo’s parents built the second unit in 1983 on a 1.2-acre parcel in Woodacre, without permits. In 2008 Mr. Arroyo and his brother, then co-owners of the property, applied for an amnesty permit offered as part of a temporary county program. (Mr. Arroyo and his wife, Catherine Sanner, became the sole owners in 2010.) But the appearance of additional square feet between the original application for the permit and its approval in 2013 led the Deputy Zoning Administrator to order the offending footage removed late last year as part of a design review decision. The owners appealed to the Planning Commission. 

It is possible that Mr. Arroyo will have an out. The agency plans to propose development code amendments this summer that will likely include an expansion of the allowed size of second units—from 750 to perhaps 1,000 square feet. But there’s no guarantee that the idea will get approval from the commission or the Board of Supervisors, which has turned down the request before. But if 1,000-square-foot units are deemed acceptable, Mr. Arroyo might have a path to legalize the addition.

The agency has tried, and failed, before to get the bigger allowance; the last attempt was about three years ago, Mr. Lai said. But it will try again because there is a need for affordable housing for small families in the county. “You know, 750 square feet is probably good enough for a one-bedroom second unit, but it’s stretching it for two bedrooms,” Mr. Lai said. 

The 2008 amnesty program was meant to provide homeowners with a way to legalize second units. But second units larger than the existing 750-square-foot cap could only be legalized if they were built before 1987. (Units under that cap could have been built as recently as 2003. Units built after that year weren’t eligible for the program.)

At the commission hearing, Mr. Sanner said his daughter and son-in-law started to remodel their home at 312 Redwood Drive soon after submitting the application for the amnesty permit. Inspections revealed rot problems that led them to tear down the main house and rebuild it. They also installed a new septic system after a neighbor voiced concerns about the old one. Because of the septic issues, the amnesty permit wasn’t issued until the fall of 2013.

The square footage reported to the agency in 2008 was 905 square feet. By 2013 the second unit was up to 998 square feet. The Deputy Zoning Administrator said last December that those extra 93 square feet must be removed to comply with the amnesty permit and design review for the home.

There is some confusion about precisely where those square feet came from. During the hearing last month, Mr. Sanner admitted that sometime between 2008 and 2013, they made a “slight addition” that amounted to about 50 square feet. The rest of the differences, he said, appeared to arise from rough calculations submitted when the amnesty permit was applied for, which were not completely accurate. (He added that an unpermitted yurt had also been removed from the property to comply with a code enforcement request.)

Mr. Sanner pled with commission to uphold his appeal despite the 50-foot modification. “Our argument is that it substantially complies with the amnesty permit. It makes no sense to require any reconstruction to remove a portion,” he said.

Some of the commissioners—who spent much of the hour-long discussion just trying to piece together a timeline—seemed to hope for a loophole in the code, so they could uphold the appeal. Since the amnesty permit was approved in 2013, they wondered, could it be construed as an approval of all construction until that point in time?

But planner Jeremy Tejirian said the amnesty program and county code were absolutely clear on one thing, at least: for a building over 750 square feet, the agency could not permit additions built after 1987. Period. 

“We have no permit we can issue…We’re sort of stuck in this quandary,” Mr. Tejirian said. To comply with the amnesty permit and current county code—and get a retroactive building permit for the structure—those extra square feet have to go, he explained.

“Why is it before us if we can’t act on it?” Wade Holland, the commissioner representing West Marin, asked at one point. Mr. Tejirian responded that if the commission decided the facts presented by the agency were wrong, it could make a different ruling. “The problem is, that’s not true,” he said.

This week, Mr. Lai added that even in cases in which additions seems small, lax enforcement can create a slippery slope. “If we start going down the road of, ‘Oh, this additional square footage is acceptable,’ how are we able to enforce our codes?” 

Mr. Tejirian recommended that the commission deny the appeal, which would put the project in the hands of code enforcement. (He later added that code enforcement has hundreds of open cases and is usually busy addressing the most egregious violations that pose health or safety threats.)

But commissioners seemed loath to force Mr. Arroyo to tear down part of his father-in-law’s home, particularly since nothing had been added since the amnesty permit was finalized.

One commissioner, Margot Biehle, did echo Mr. Lai’s concerns. “There is the question of the slippery slope and all these illegal buildings, particularly in West Marin, who could now look at this and say, ‘Well, we’re just gonna do our work and beg for forgiveness later,’” she noted.

Mr. Tejirian responded: “Well, yes, even while they were in the process of trying to legalize what they had, they kept on constructing.”

Ms. Biehle said the owner could have been a “better actor.” But, she added, “It’s ameliorated, in my view, by the fact that they came forward in the first place and asked for amnesty and have been, for the most part, forthcoming with what their building was.”

Despite Mr. Tejirian’s recommendation to deny the appeal, he complimented the home’s design during his presentation to the commission, calling it a “lovely structure.” It was an example, he said, of how larger second units can “fit nicely into an existing site.” 

He suggested that commissioners keep the project in mind when he brings development code amendments before them, which will likely be sometime this summer and include the allowance for larger second units.

“Hopefully this will be fresh in our memory when the development code [amendments] come along,” one commissioner said before the seven ayes were cast in favor of Mr. Arroyo.

Mr. Arroyo is grateful for the commission’s call. “We still have to work through building permit issues pursuant to the amnesty rules, but we now see that there is a light at the end of the tunnel,” he said in an email to the Light.