The occupants, who have lived there only since last summer, don’t know how the place next door fell into such disrepair. By the time Jannelle Davis and her boyfriend rented this 900-square-foot one-bedroom in northwestern Detroit, it was already so decrepit that even the scavengers seeking to strip it of copper were long ago done and gone.

“It’s disgusting,” Davis said, balancing her hair-grabbing 3-year-old on her hip. “This is what we could afford, and we’re doing our best with it. But I worry about my son crawling through there when I’m not watching.”

This block of Greenview, say Detroit civic leaders, is precisely why they are undergoing an ambitious, high-tech eight-week process of looking over all 380,217 parcels in this 139-square-mile municipality to identify what is worth keeping and what should be recommended for the bulldozer.

The legwork for the $1.5 million Motor City Mapping survey, which deploys more than 60 three-person teams fanned out daily across the city to provide assessments and photos via tablet computers, is due to be completed by the first week of February.

The contingents do “windshield” inspections, answering a checklist of questions from the curb on their tablets about the physical condition of a place and whether anyone lives in or uses it. Their responses, along with photos they snap, are beamed immediately to the headquarters on the third floor of a former Corvette-factory-turned-technology-startup-incubator downtown, where quality control reviews the input.

“Sometimes they get out of the car if something is blocking their view, but they are not walking into someone’s yard or into someone’s house,” said Sean Jackson, the project’s primary supervisor. “This is merely triage. We’re getting a base of what’s out there.”