Napa will take advantage of the slowdown in new development to begin a citywide survey of its historic resources.

Many buildings from the city’s century and a half of growth are architecturally and culturally important, but have never been evaluated as to their significance, according to Marlene Demery, the city’s interim planning manager.

Napa hired Page & Turnbull Inc., a San Francisco historic preservation firm, to analyze the forces that have shaped building styles over the decades.

Riverboat and railroad eras, devastating floods and changes in agriculture have shaped how the city grew and the styles of buildings, Demery said.

Once these historical influences are mapped out, Page & Turnbull will do an intensive survey of homes and commercial structures in the Soscol Avenue/East Napa area.

The city promised to do this survey when it approved the Soscol Gateway redevelopment project last year. Some residential areas near Napa Valley Exposition could qualify to become a historic district, Demery said.

The historic resources project will be launched on Dec. 16 when Page & Turnbull holds a community meeting at the Napa City-County Library to gather family stories and photographs about buildings more than a half century old.

Oral histories will be recorded and old photos scanned into computers as a first step to documenting the economic and natural forces that have shaped the city’s development, Demery said. “There may be some tidbits of history that no one knows,” she said.

Since the late 1960s, the city has fitfully tried to inventory its historic buildings, but the methodology was inconsistent, Demery said.

The current Historic Resources Inventory is about 20 years out of date and filled with sometimes shaky assessments of a structure’s importance, she said.

Page & Turnbull will help the city adopt new standards for future neighborhood-by-neighborhood historic surveys, Wendy Ward, a city Cultural Heritage Commission member, said.

“This is a huge step forward,” Ward said. Old surveys were often done by driving down a street with a clipboard and a camera. Future surveys will be rooted in greater historical research, she said.

The California Office of Historic Preservation awarded a $25,000 grant for a citywide historical context study. The city’s redevelopment agency is putting up $50,000 for the Soscol/East Napa survey.

Soscol/East Napa has an estimated 75 buildings that might qualify for the California Register of Historic Places, said Jennifer LaLiberté, the redevelopment agency’s senior project coordinator. Only 33 of these buildings are on the current Historic Resources Inventory, she said.

Many neighborhoods away from the city’s 19th century core have structures of historic importance that have never been looked at, Ward said. Browns Valley, for example, has farmhouses and barns from early times that should be tallied, she said.

A more comprehensive historic inventory may protect Napa from repeating some of the wrong-headed decisions of the past, Demery said.

The city’s redevelopment program destroyed a lot of downtown buildings in the ’70s that were thought to be blighted. “Now we look at the pictures and think we should have saved them,” she said.

Napa once had a Chinatown, but now there’s nary a trace. “It’s a shame,” Demery said. “Other communities have embraced their cultural heritage throughout history.”

An improved Historic Resources Inventory will give property owners information that could be useful during a restoration project. At the very least, owners will have a more informed story about their house or commercial building, Demery said.

Properties that score high for historic importance will come under greater city scrutiny if there is a proposal to demolish or significantly alter the facade, Demery said.

Demery said a half dozen neighborhoods might need detailed surveys such as the one that will be done for the Soscol Gateway project.

The Cultural Heritage Commission is asking the City Council to fund one study annually if future state grants are not forthcoming.

The community meeting on Dec. 16 will be from 5:30 to 7 p.m. in the Community Room of the Napa City-County Library, 580 Coombs St.