Housing Development in Montgomery County since 1940

This story map illustrates the history and geography of housing development in Montgomery County since 1940. In addition to showing how housing spread across the county over time, it breaks housing down by three types—single-family detached homes, townhomes, and units in multi-family buildings—to show the relationship between land availability and development trends.

As the county grew and matured, it used land for housing more intensively. In 1940, single-family detached housing occupied almost all the county’s residential land and housed almost all the county’s population. By 2024, single-family detached homes still occupy almost all the residential land but house less than half the population.

In 1940, 92% of the county’s housing units were single-family detached homes, which occupied nearly all (99%) of the residential land. By 2024, a majority of the county's housing units (54%) were in structures other than single-family detached homes, such as apartment buildings or townhouses. However, the percentage of residential land occupied by single-family detached homes hasn’t changed much, ceding only about eight percent of the total land area.

Most housing units in the county are now townhomes or multi-family buildings, and few new single-family detached homes are built. With little space left to expand, the county must now make the most of its available space. As the storymap shows, this trend is not new to the county. Multi-family housing construction has been outpacing construction of single-family detached and attached housing combined for more than two decades. The challenge will be to find room for housing in a county in which almost all of the residential land is already occupied by single-family houses.

Data Notes

The housing data in this storymap comes from the Maryland State Department of Assessment and Taxation (SDAT) property records for Montgomery County and includes all records categorized as housing as of January 1, 2024.  Units that are demolished and rebuilt are only recorded once in the database; the year built is the year of new construction. When looking at totals, this results in a minor discrepancy between current housing stock and historical building activity.  

The pie charts and bar charts showing area and units by housing type over time do not include units in agriculturally zoned land, but the map and map totals do include these units.

Note that totals in this storymap do not match totals in an  August 2024 blog  about housing construction over time in Montgomery County, which used a database that reflected units built as of January 1, 2022 and excluded senior housing.