From now on, you won’t be able to build a really big — say 6,000- to 16,000-square-foot — house on most lots in Los Trancos Woods, even if the new sewers can serve it.
On Sept. 11, the San Mateo County Board of Supervisors amended the zoning for 137 lots in the former summer-home community to limit the size of houses that can be built in two zones.
The new zoning replaces the old means of calculating maximum house size with a new formula that bases total square footage of a house on the size of the lot. For a lot of 7,500 square feet, the maximum house will be 3,200 square feet. For larger lots, the maximum house size will increase by 10 percent of the lot area above 7,500 square feet.
Under the new zoning, a half-acre lot can support a house of 4,628 square feet, according to the county staff report.
More than 16,000 square feet could be built under previous zoning, which allowed a three-story house to cover 25 percent of the lot.
Amazingly, no one from the community spoke at the hearing, either for or against the dramatic change in zoning restrictions.
Planning Director Lisa Grote presented the zoning amendments for two areas of the foothill community. The board voted unanimously for the new limits.
Supervisor Rich Gordon congratulated the community on coming together to support a compromise on maximum house size. He recalled the first community meetings about eight years ago as full of “contention, disagreement, and argument.”
“Sewers were the impetus,” said Armin Staprans of Los Trancos Woods, who chaired the semi-official committee that finally came up with the compromise adopted last week.
Sewers for small wooded lots that often have problems with septic tanks have been under discussion in the community for almost 10 years. Finally, in June, legal and financial issues had been resolved, and construction started on sewers that will serve some 60 lots — for starters. They should begin service this winter.
Sewers mean that much larger houses can be built. With no sewers, the size of a house is limited by the capacity of the lot to support a septic tank drain field; with sewers, that limitation goes away, and house size is determined by zoning.
“In the beginning, the subject was very contentious,” Mr. Staprans said. Some people wanted to keep house sizes way down, while property rights advocates wanted no limits. “We really got nowhere; the county threw up its hands.”
As it became clear that the sewers were coming, Mr. Staprans and his group came together to seek common ground. They decided not to tinker with zoning details like setbacks, height and slope, he explained. Instead, the committee focused on a formula that related total floor area to lot size.
“We found the neighborhood could live with that,” Mr. Staprans said. “We were racing with sewers.”
A survey of the community generated an 86 percent response; 72 percent supported the compromise, Ms. Grote reported.
As the time neared for sewer construction to begin, the county revived the planning effort. A community meeting in June drew strong support, and the Planning Commission approved the community proposal in August, with no opposition.
“Everyone was notified,” Mr. Staprans said. “Under the previous zoning, you could build a 9,000-square-foot house on a sixth of an acre.”
