ADU Potential Atlas
LiveHow many backyard homes could the neighborhoods of Greater Cleveland hold?
Checks every single-family lot in 10 Greater Cleveland cities against public parcel, building and zoning records, and shows how many could take an accessory dwelling unit (a backyard cottage or a garage conversion) under current, proposed and hypothetical rules.
What it does
- Screens 180,517 single-family lots. 89% have physical room for an ADU: after keeping clear of lot lines, the house and any garage, a 20 ft footprint fits behind the house, or there is a garage to convert.
- Encodes each city's own rules with citations. Under today's rules 22,339 lots are both allowed an ADU and have room; uncertain rules are shown as unknown, never as zero.
- Checked by hand: 300 sampled lots were judged from aerial photos before seeing the answer, and agreed with the screen 95% of the time.
- Turns lots into housing with an adjustable uptake assumption based on cities that reformed their rules. At the default 2% over 10 years, a by-right reform in all 10 cities would add about 3,200 homes, 0.9% more housing.
- Static from end to end: a Python pipeline publishes JSON and GeoJSON chunked by H3 hexagon to a static site. No database and no server.
Screening estimates from public data, not legal determinations or a forecast. It is informative, not advocacy, and a specific property needs a site visit and the city planning office.