A Chicago building permit row is an administrative record with a defined scope. It is not a complete history of a property, and its date does not automatically tell you when construction began or finished. Before using a row to explain a renovation or count neighborhood activity, identify the source, the event its date describes, and which records the source excludes. Chicago provides several official...
Real Estate
Philadelphia Atlas can bring several kinds of city information onto one screen, but a shared map does not make every identifier interchangeable. An address describes a location in familiar language. A property assessment account and a Department of Records map reference serve different administrative purposes. Before comparing information across Atlas panels, establish which identifier each panel is using...
A Seattle permit status is useful only when you know which record it describes and which documents belong to that record. A site can have several applications, permits, and historical files. Reading one status at the top of a result and treating it as a verdict on the whole property skips the relationships that make the information meaningful. Seattle's Department of Construction and Inspections, or...
A table headed units in structure can sound like a building inventory. In ACS housing tables, however, the categories generally describe housing units according to the size or type of structure that contains them. Reading a count in an apartment building category as a count of buildings can multiply the apparent building inventory and distort a neighborhood description. This guide uses fictional...
A home described as having five rooms does not necessarily have five bedrooms. In Census housing statistics, rooms and bedrooms are separate measures. Occupants per room uses the room count, not simply the number of bedrooms. Confusing these concepts changes the denominator of a housing indicator and can lead to unsupported claims about how a home is used. This guide explains the statistical distinctions...
A chart of reasons for moving can tell a useful housing story, but its wording matters. A reported main reason describes the answer recorded for a move. It does not measure every consideration behind that decision, establish what would have happened under different circumstances, or reveal the preferences of everyone who stayed. Those distinctions are essential when translating national survey findings...
A New York City building search can look incomplete because the researcher stopped in the first system that returned an address. The Department of Buildings directs readers to both the Building Information System, known as BIS, and the DOB NOW Public Portal. The useful task is matching the question and record type to the system that holds it, then preserving the identifiers needed to connect the...
A spreadsheet contains the median rent for every neighborhood. Averaging those medians produces one convenient citywide number. The calculation is easy, but the result is not generally the median rent of the city's households. Each neighborhood median is a summary that has already discarded much of its underlying distribution. Census guidance notes that derived estimates such as medians cannot simply...
Two neighborhoods report renter shares of 20% and 80%. Their simple average is 50%. That average describes the two percentages when each neighborhood receives equal weight. It does not necessarily describe the renter share of all occupied units across the neighborhoods. For that question, the counts behind the shares matter. Census housing tables identify tenure categories and their occupied housing...
A housing report can contain two income figures that look almost interchangeable: median household income and median family income. Replacing one with the other changes the population being summarized. It can also change whose earnings enter a particular income total. Before using either measure to describe a neighborhood, identify the unit of analysis, the people whose income contributes, and the...