New Housing Share
The share of a tract's housing units that stand in structures built in 2010 or later.
The share of housing units in a tract that stand in structures built in 2010 or later.
The Census Bureau defines year structure built as "when the building was first constructed, not when it was remodeled, added to, or converted." Housing units under construction "are included as vacant housing if they meet the housing unit definition, that is, all exterior windows, doors, and final usable floors are in place," and for mobile homes, houseboats and recreational vehicles "the manufacturer's model year was assumed to be the year built." The counts "relate to the number of units built during the specified periods that were still in existence at the time of interview" (ACS Subject Definitions).
The question is asked at both occupied and vacant units, and the denominator is every housing unit in the tract.
This measure records construction that was completed and is still standing. Permits record construction that was authorised, which may or may not have followed — see permit activity. Read together, the two describe delivered supply and intended supply.
Metrics in this family#
Considerations#
The 2010 cut-off is fixed while time is not. The span it covers lengthens with every release, so the measure means "built in the last decade and a half" today and will mean a longer period later. It is a comparison between tracts at one moment, not a rate of construction.
The Bureau's own construction-period bands are redefined periodically, with the newest band advancing as releases go on. Where a published band does not align with the 2010 cut-off, the share is read from whichever bands the vintage in question actually published.
Because the denominator is the whole standing stock, the share reflects both what was built and how much the tract already contained. The same volume of construction produces a much larger share in a lightly built tract than in a dense one, so the measure describes composition rather than volume.
Year built is reported by the occupant or owner rather than taken from permit records, and a substantially rebuilt building keeps its original construction year.
ACS 5-year windows overlap. Each vintage shares four of its five years with the vintage before it, so movement between adjacent vintages reflects smoothed rolling estimates rather than independent annual readings.
Census tract boundaries were redrawn for the 2020 census. Estimates published on earlier boundaries are carried onto current ones before use — see geography.
In tracts with few housing units the estimate rests on a small sample and carries a wide margin of error.
References#
- 1ACS Subject Definitionshttps://www2.census.gov/programs-surveys/acs/tech_docs/subject_definitions/2024_ACSSubjectDefinitions.pdf