Automated edits/whammo

whammo (on osm, edits, contrib, heatmap, chngset com.)

DC rowhouse tag modifications

Motivation

DC's buildings were imported into OSM in 2010, with all buildings receiving the generic building=yes tag. This has meant that apps like StreetComplete ask users to fill out details about all of DC's many structures, leading to inconsistent or incomplete entries. However, many residential buildings in the District are rowhouses (also called townhouses), and should have the tags building=house and house=terraced. A systematic approach to classifying these structures will create a uniform standard for DC's building classification, allow StreetComplete users to focus on quests that are harder for remote mappers to address, and generally improve the quality of OSM data in the District.

The District has about 160,000 building ways according to the Ohsome dashboard. My very rough estimate is that about 40,000-70,000 of them would qualify as rowhouses covered by this automated edit proposal.

Process

Using JOSM, I plan to go ward by ward, starting with Ward 8 and going down. Some wards, like Ward 2 and 3, have relatively few rowhouses compared to Wards 6, 7, and 8.

Download all buildings within a given ward of DC in JOSM using an Overpass query.
Use the search function with the following string, explained below:
```
parent (type:node ways:2-) "addr:street" building areasize:30-300 -(amenity OR shop OR office OR building=retail OR (building=house AND house=terraced))
```
This search looks for nodes that belong to two or more ways, and selects the parent objects of those nodes. Of those parent ways, it selects ways with addr:street=* and building=*, with an area between 30 and 300 square meters. Of those results, it removes ways that have an amenity=*, shop=*, office=*, or building=retail tag, or already has the proper rowhouse tags.
Visually scan the search results for structures that are duplexes, and remove them from the selection. See step 6.
Visually scan the selection for other structures that do not appear to match a typical terrace, such as adjacent garages, sheds, or other buildings, and remove them.
Update building=yes to building=house and add house=terraced.
Repeat step 2, updating structures that appear to qualify as duplexes and were removed from the selection in step 3, from building=yes to building=semidetached_house.
Upload modifications in geographically compact changesets using the "Upload selection" function, with no more than 10,000 changes per changeset. All changesets will link to this page.