"Passive open spaces are desirable and necessary to maintain the quality of life enjoyed by the residents of the community," according to the ordinance the Town Council unanimously voted to amend last month.
Development within 100 vertical feet of a major ridgeline, or on hills with a slope of more than 30 percent, is currently prohibited. However the code allows for an exception to the rule for parcels where there's no other feasible location to build.
And, in those exceptional cases, the code's language treats hillside and ridgelines equally, though when faced with a choice between the two the town would value preservation of ridgeline areas first and foremost, town staff said.
To clarify this, the language banning hillside developments was removed. This gives the town some wiggle room for cases in which building on a slope - even one with more than 30 percent steepness - would be preferable to building on the ridgeline.
"It kind of comes on a site-by-site basis," said David Crompton, principal planner for the town.
Another section of the ordinance prohibits any new subdivision that would result in a building site close to a major ridgeline.
It was tightened to also forbid any subdivision resulting in a parcel that had no feasible building site that wasn't on a ridgeline or an over-30 percent slope.
"We wouldn't approve the subdivision," Crompton said.
This limits potential construction on steep slopes or ridgelines to parcels that already exist in town.
"Since Danville incorporated you don't see much ridgeline development except the stuff that was already there, approved by the county," Crompton said. "And we won't be creating any more."
The ability to request an exception from this rule was also deleted from the section.
The decision to stiffen restrictions was an outcome of the Skyvilla lawsuit that ended in the construction of a 7,000-square-foot home on the Danville ridgeline last fall.
When the Planning Commission and Town Council denied Skyvilla's application to build the home the company filed a lawsuit, saying the spot was the only suitable place to build. The council's denial was overturned by the Contra Costa County Superior Court.
After the long legal battle the council finally approved the development in September. It now sits at 1621 Lawrence Road, overlooking Dougherty Valley. The town then decided to revisit the ridgeline ordinance to have it better reflect Danville's values.
Per procedure the council voted a second time on the changes at its Aug. 12 meeting. The ordinance goes into effect 30 days after that.