MORAGA -- One hundred years ago, passengers traveling from Oakland to Chico on what was to become the Sacramento Northern Railroad could stop and visit the Moraga Barn, a two story hotel building nestled amid the town's pear and walnut trees.

Cattle grazed nearby and as developers were enticed by the area's rolling ranch land, they lay down roots in subdivided property sold to them by James Irvine's Moraga Land Company. Over time, the 2,500-square-foot hotel became a mercantile and library, and gained its permanent name as a 1930s Prohibition-era bar, when the "n" was added to comply with a State law restricting use of the term "bar."

Sadly, after serving various purposes for nearly 63 years, the Moraga Barn was left to decay in about 1997.

That might have been the end of the story if not for Canyon Construction. Searching for home offices, Chris Avant's company purchased the Moraga Barn with a plan to restore the aging building to its former glory, and more.

Last year, a renovation project preserved and transformed the 100-year-old building as a state-of-the-art model of sustainability and a home for the company.

Upon its completion, the US Green Building Council certified the Moraga Barn at the LEED Platinum level (the top of five categories). Everything from construction materials to energy used to water efficiency contributed to the rare designation.

But what residents and admirers of historic buildings will appreciate at an upcoming May 4 open house, is the melding of old and new in the old Barn's "second century" identity.

During the three-hour "Pop In at the Barn!" event, guests can check out the building's reclaimed redwood lumber detailing, tiles repurposed from San Francisco's Union Square, and East Bay artisan Chuck Splady's recycled steel stair railings. Or walk across the courtyard and learn about the 5,000-gallon tanks buried underground that collect runoff rain water for irrigating the property. Or peer through the marvelous third-level glass-bottomed floor and note the natural light and openable windows that both heat and cool the interior space without using carbon-emitting, man-made energy sources.

Best of all, Canyon Construction has created not only a home for themselves, but a rental space for the community. A news release promotes use for corporate functions, weddings, wine tastings and special celebrations. A series of "Pop In at The Barn!" events will kick of the new venue and introduce visitors to the facility's preferred vendors.

The open house on Saturday, runs from 11 a.m. to 2 p.m. at the refurbished building, 925 Country Club Drive in Moraga. For information about rental rates and facility features, visit http://www.moragabarn.com/