ACS Housing Units by Year Built Boundaries

Overview This feature service contains U.S. Census geography boundaries enriched with American Community Survey housing age characteristics. It brings together state, county, and census tract polygons with counts and median-year measures that describe the housing stock by year built, along with owner-occupied and renter-occupied housing patterns. Feature Layers State: State boundaries with ACS housing-unit-by-year-built summaries, including total housing units, housing units by construction period, ownership tenure breakdowns, and median year built measures. County: County boundaries with the same housing age and tenure indicators, supporting county-level comparison of housing stock across the United States. Tract: Census tract boundaries with detailed ACS housing-age and tenure summaries for fine-grained neighborhood-scale analysis. Geographic Coverage The service covers the United States using Census Bureau administrative and statistical boundaries. It includes statewide, countywide, and census tract geography for broad-to-local housing analysis. Use Cases Mapping the age distribution of housing stock across the United States Comparing owner-occupied and renter-occupied housing by construction period Supporting housing condition, neighborhood change, and redevelopment studies Analyzing median year built patterns at state, county, and tract scales Data Notes The layers include standard Census geography identifiers and automatically maintained shape fields, making the service suitable for display, filtering, and spatial analysis in ArcGIS applications. The housing attributes are derived from American Community Survey tabulations on year structure built and occupancy tenure.概述 本要素服务涵盖经美国社区调查（American Community Survey, ACS）住房年限特征补充完善的美国人口普查地理边界数据集。其整合了州、县及人口普查区（census tract）的面状地理要素，包含按建造年份分类的住房存量统计量、建筑中位年份指标，以及自有自住与租赁租住的住房保有模式数据。 要素图层 州级图层：包含美国各州行政边界，附带ACS按建造年份整理的住房单元统计数据，涵盖住房总单元数、按建造时段划分的住房单元数、住房保有类型细分情况，以及建筑中位年份指标。 县级图层：包含美国各县行政边界，附带与州级图层一致的住房年限与保有类型指标，可支撑全美范围内县级尺度的住房存量对比分析。 普查区图层：包含人口普查区（census tract）边界，附带详细的ACS住房年限与保有类型统计摘要，支持精细化的社区尺度分析。 地理覆盖范围 本服务基于美国人口普查局的行政与统计边界实现全美全域覆盖，包含州级、县级及普查区级地理要素，可满足从宏观到微观的住房相关分析需求。 应用场景 1. 绘制全美住房存量的建造年限分布图谱 2. 按建造时段对比自有自住与租赁租住的住房分布情况 3. 为住房状况评估、社区变迁研究与再开发项目提供数据分析支撑 4. 在州、县及普查区尺度开展建筑中位年份分布规律分析 数据说明 本要素图层包含标准的美国人口普查地理标识符与自动维护的空间形状字段，可适配ArcGIS应用中的可视化展示、数据筛选与空间分析需求。住房相关属性数据均源自美国社区调查中关于建筑建造年份与住房保有类型的统计制表结果。