Seeking to hold the line against large-scale development on the Gaviota coast, a county design panel on Friday told planners to deny a proposed 10,000-square-foot home visible from Highway 101.

The project -- which would sit on a 17-acre-parcel and include a 1,200-square-foot barn and 1,368-square-foot guesthouse -- violates requirements that builders obscure projects from public view and blend them into the natural environment, members of the Board of Architectural Review said.

While the panel lacks the authority to deny the project, county planners had asked for comment as they move closer to a decision on whether to grant a permit for the home. They expect to rule on the matter next month.

The project is one of 135 new development proposals pending on the pristine rural coastline widely considered the last of its kind in the county and possibly in Southern California.

The glut of applications follows an unsuccessful campaign by environmentalists to win national seashore status for the coastline.

The home proposed on land owned by the Ballantyne family is the second large-scale residential project to come up for review.

The first -- a 10,370-square-foot home also visible from the highway -- cleared the Planning Commission in May and could come before the Board of Supervisors on appeal.

Without voting, panelists provided informal comments to project designer Barry Berkus and his staff. Several highlighted the proposal's failure to meet a visual resources policy that prohibits new buildings that can be seen from a public place.

"This is obviously on the top of a ridge line," said board member Valerie Froscher, who also asserted that the modernist-style building was wrong for the landscape. "The design and scale is not compatible. It is too large."

Mr. Berkus disputed the panel's findings. He said a screen of vegetation and earthen mounds would block the home from the highway but still provide an ocean view.

"The house is going to be obscured by the land forms in front of it, plus landscaping," said Mr. Berkus, who insisted that the owner of the property had a right to an ocean view. "Everyone below has a view, and they're unsightly houses."

He also said that well-designed homes visible to the public complemented the area's natural beauty. "We go to visit architecture when we travel," Mr. Berkus said, referring to hillside villages in Italy. "We don't go to visit barren hillsides."

Board members also questioned the size of the lawn adjacent to the 314-foot-long home.

"The turf is quite extensive," said board member Bethany Clough.

Agents for Mr. Berkus said the project size was appropriate because it sits next to an "urbanized" area, Rancho Embarcadero -- a description that county planner Allen Bell rejected.

"The area is designated rural," Mr. Bell said.

Gaviota Coast Conservancy spokesman Mike Lunsford called the proposal "starkly inconsistent" with the area's character.

The Board of Architectural Review provides input on the design quality of proposed buildings. If planners deny the project, Mr. Berkus and his clients could file an appeal to the Planning Commission.

Foreshadowing a project-by-project showdown over development, Ms. Froscher said future proposals would receive intense scrutiny.

"The Gaviota coast is at such a complete crossroads," Ms. Froscher said. "Any move that anyone makes is under a microscope."

e-mail: bmcmanigal@newspress.com