A housing unit is owner occupied if the owner or co-owner lives in the unit even if it is mortgaged or not fully paid for. The owner or co-owner must live in the unit and usually is Person 1 on the questionnaire. The unit is "Owned by you or someone in this household with a mortgage or loan" if it is being purchased with a mortgage or some other debt arrangement such as a deed of trust, trust deed, contract to purchase, land contract, or purchase agreement. The unit also is considered owned with a mortgage if it is built on leased land and there is a mortgage on the unit. Mobile homes occupied by owners with installment loan balances also are included in this category.
A housing unit is "Owned by you or someone in this household free and clear (without a mortgage)" if there is no mortgage or other similar debt on the house, apartment, or mobile home including units built on leased land if the unit is owned outright without a mortgage.

All occupied housing units which are not owner occupied, whether they are rented or occupied without payment of rent, are classified as renter occupied. "No cash paid" units are separately identified in the rent tabulations. Such units are generally provided free by friends or relatives or in exchange for services such as resident manager, caretaker, minister, or tenant farmer. Housing units on military bases also are classified in the "No cash paid" category. "Rented for cash rent" includes units in continuing care, sometimes called life care arrangements. These arrangements usually involve a contract between one or more individuals and a health services provider guaranteeing the individual shelter, usually a house or apartment, and services, such as meals or transportation to shopping or recreation. (For more information, see " Meals Included in Rent .")

From 1996-2006 the American Community Survey questions were the same. Starting in 2006, the instruction Mark (X) ONE box. was added following the question, and the instruction Include home equity loans. was added following the response category "Owned by you or someone in this household with a mortgage or loan?" Additional changes introduced In 2006 included revising the wording of two of the response categories from "Rented for cash rent?" to "Rented?" and "Occupied without payment of cash rent?" to "Occupied without payment of rent?"

This measure divides the room distribution into two equal parts: one-half of the cases falling below the median number of rooms and one-half above the median. In computing median rooms, the whole number is used as the midpoint of the interval; thus, the category "3 rooms" is treated as an interval ranging from 2.5 to 3.5 rooms. 'Median rooms' is rounded to the nearest tenth. (For more information on medians, see the discussion under "Derived Measures.")

'Aggregate rooms' is calculated by adding all of the rooms for housing units in an area. A value of "10" is assigned to rooms for units falling within the terminal category, "9 or more rooms." (For more information on aggregates, see "Derived Measures.")

Since 1999, the American Community Survey provided response categories from "1 room" to "9 or more rooms." The 1996-1998 American Community Survey question provided a space for a write-in entry.