ALAMO -- One of Alamo's most historic homes, the 84-year-old Westminster Retreat, is back on the market after a potential sale to a local developer fell through.

Branagh Development of Danville had planned on purchasing the retreat at the end of Hemme Avenue and building luxury homes on the site, with a deadline of the end of August to finalize a deal.

On Thursday, company CEO Matt Branagh called the deal "likely dead."

"In our area, things are tough to get entitled," he said. "The risk sometimes outweighs the reward."

Set on eight acres near Las Trampas Regional Wildlife Preserve, the 8,000-square-foot, three-story Westminster manor was built in 1929. Sporting redwood paneling inside, the mansion has 20 rooms, including eight bedrooms, six bathrooms and numerous fireplaces.

The property, which includes the seven-bedroom Carriage House Lodge, a meditation garden and outdoor seating, has been rented out as a retreat for churches, businesses and nonprofit groups for the past 60 years.

The Presbytery of San Francisco, based in Berkeley, has owned Westminster Retreat since purchasing it from the Englehart family in 1953. The church has been looking for a buyer since last year, according to Pastor Leonard Nielson, chairman of the Presbytery's finance and property oversight committee.

The property, managed by United Camps Conference, will cease operation as a retreat Dec. 31.

Nielson said the church would like the eventual buyer to keep the main house intact, but it is not requiring its preservation as part of the sale.

"We don't want the land to be left vacant," he said. "It may just be the biggest house-sit in the world."

The Presbytery is asking $4.65 million for the property.

"I'd be surprised if we don't have a buyer by mid-November," Nielson said.

News of the manor's availability, at least temporarily, could breathe life into the efforts of a handful of Alamo residents looking to preserve it as a historic site. DeNova Homes of Concord, which also entertained ideas of purchasing the Westminster Retreat, conducted a historical analysis of the manor in 2012. The report concluded that the main house was of "definite historical and historic architectural interest" and recommended it be saved for rehabilitation.

However, Branagh said it's only a matter of time before the retreat is sold and replaced by homes.

"It's zoned residential, and therefore I think most likely that site will be developed, even if it's not us," he said.

Contact Jeremy Thomas at 925-847-2184. Follow him at Twitter.com/jet_bang.