SAN FRANCISCO -- The homeowners at Unity Homes here aren't experts in green building, but they're still in charge of a renovation that is making their community of aging government-subsidized co-op apartments a healthier, more energy-efficient place to live.

“You don't have to be the supreme green expert to go green,” said Cathy Craig, senior program officer for Bay Area Local Initiatives Support Corp. (LISC). LISC, a national nonprofit affordable housing investor, provides technical assistance to help groups like Unity's co-op board perform green rehabs on existing affordable housing properties.

Now LISC is sharing that information with anyone who wants it — for free. Bay Area LISC has teamed up with Build It Green, a local nonprofit, to write Green Rehabilitation of Multifamily Rental Properties. (The information in the guide applies to both rental and homeownership multifamily projects, said Craig.)

The 68-page guide is a distillation of everything LISC has learned in its years of green rehabs. The two nonprofits have made the publication available for download at www.bayarealisc.org.

Many affordable housing owners have little experience in doing green redevelopments. That's especially true at Unity Homes, which was built in 1974 under the Department of Housing and Urban Development's Sec. 236 limitedequity co-op program. Unity's 94 garden apartments are owned by its residents.

Planning the renovation, the homeowners had advice from green experts at LISC and Practica Consulting, based in Austin, Texas. However, many redevelopers aren't so lucky. “Sometimes for a rehab job you might not even have an architect,” said Craig.

LISC and Build It Green kept Unity's owners and others like them in mind as they designed the guidebook, an assessment tool that will help owners decide which green building materials and techniques make sense at their aging properties from the start of the rehab process to the finish.

The guide includes definitions and basic descriptions of green techniques. Its focus on rehabilitation of existing properties sets it apart from many other green guides and standards. “It doesn't presume that you can re-site the buildings,” said Craig.

Each green building technique or material listed in the guide is rated both for its extra cost and for the benefit it will bring to a property. Items covered range from low-cost paints that don't emit harmful gasses to much more expensive solar systems. The authors include cost information wherever possible.

Energy efficiency is especially important to older affordable housing properties like Unity that struggle to cover rising utility costs with fixed operating budgets set by HUD.

Work is expected to finish on Unity's green renovation by the end of 2008. Financed by a Federal Housing Administration Sec. 221(d)(4) substantial rehabilitation loan, the improvements will include Energy Star-rated windows and appliances, water-saving fixtures, and new, durable cement board siding—features that should save the 34-year-old property energy and maintenance costs for decades to come.