Glossary

A reference for terminology used in housing studies with a focus on the United States.

Absorption period: The period of time necessary for a newly constructed or renovated property to achieve the stabilized level of occupancy. Begins with the issuance of the first certificate of occupancy and ends when the last unit reaches the stabilized occupancy with a signed lease.

Absorption rate: The average number of units rented each month during the absorption period.

Acceptable rent burden: The rent-to-income ratio used to qualify tenants for both income-restricted and non-income-restricted units. Varies by funding sources and local conditions.

Achievable Rents: Also referred to as Market Rent, Achievable Restricted Rent.

ACS (American Community Survey): An ongoing survey by the U.S. Census Bureau that provides detailed demographic, social, economic, and housing data annually. The 5-year estimates provide reliable data for areas with populations as small as 65,000.

Affordable housing: Housing affordable to low or very low-income tenants.

AMI (Area Median Income): The midpoint of a region's income distribution, meaning that half of households earn more and half earn less. Used by HUD to set income eligibility thresholds for housing programs.

Amenity: Tangible or intangible benefits offered to tenants, such as recreational facilities or planned programs.

Annual demand: The total estimated demand in the market in any one year for the type of units proposed.

ARIMA (Autoregressive Integrated Moving Average): A statistical model for time series forecasting that combines autoregression, differencing, and moving averages. ARIMA(0,1,1) uses first-order differencing and a moving average term.

Asking rent: The listed rental rate for vacant units on the market.

Assisted housing: Housing where federal, state, or other programs subsidize tenant costs.

Attainability gap: Difference between housing supply and demand at each income level group.

Bedroom count: The number of bedrooms in a housing unit.

Bias: A preference that inhibits impartial judgment.

Capture rate: The percentage of qualified renter households that the property must capture to fill the units.

CBSA (Core Based Statistical Area): A geographic area consisting of one or more counties anchored by an urban center of at least 10,000 population plus adjacent counties with strong commuting ties.

CCD (Cohort Change Difference): An additive measure of population change between age cohorts: CCD = Pop(age i+5, year t+5) - Pop(age i, year t).

CCR (Cohort Change Ratio): A multiplicative measure of population change between age cohorts: CCR = Pop(age i+5, year t+5) / Pop(age i, year t).

Cohort-Component Method: A demographic projection technique that divides population into age-sex cohorts and projects each group forward using fertility, mortality, and migration assumptions.

Comparable property: A property similar to the subject in aspects like construction, size, amenities, and location, used to derive market rent and evaluate the subject's market position.

Competitive property: A property that is comparable to the subject and competes at nearly the same rent levels and tenant profiles.

Concession: Discounts offered to tenants to induce lease signing, such as reduced rent or free amenities.

Cost burden: Spending more than 30% of household income on housing costs.

Cost burden, severe: Spending more than 50% of household income on housing costs.

CPI: Consumer Price Index. A measure of inflation.

Demand: The number of households in a market area that would potentially move into proposed housing, adjusted for factors like age, income, and size.

Effective rents: Contract rent minus concessions.

FRED (Federal Reserve Economic Data): An online database of economic data maintained by the Federal Reserve Bank of St. Louis, including interest rates, employment, and economic indicators.

GEOID: A unique geographic identifier code used by the U.S. Census Bureau to identify specific geographic areas (states, counties, census tracts, etc.).

Household trends: Changes in the number of households over time due to factors like new formations, changes in size, and migration.

Housing needs assessment: An analysis of a community's housing market to determine the current and future housing needs in order to guide planning and policy decisions.

HUD (U.S. Department of Housing and Urban Development): Federal agency responsible for housing policy, including setting Area Median Income standards for affordable housing programs.

Income band: Ranges of household incomes that can afford specific rents, adjusted for program-specific limits.

Infrastructure: Services and facilities such as roads, water, sewerage, and parks.

Leslie Matrix: A matrix representation of age-structured population projection where the first row contains fertility rates and the subdiagonal contains survival/migration rates.

LIHTC: Low Income Housing Tax Credit. A federal program that provides tax incentives for affordable housing development.

Market advantage: The difference in estimated market rent for a property without income restrictions versus proposed or maximum permitted rents.

Market analysis: A study of real estate market conditions for a specific property type.

Market area: Also referred to as the primary market area from which a property draws most of its residents.

Market demand: The number of households that would potentially move into any new housing in a defined area.

Market rent: The rent an apartment would command considering its location, features, and amenities, adjusted for concessions.

Market study: A study of a specific proposal and the housing market in a defined area, used to determine housing needs.

Market vacancy rates: Metrics on rent loss due to concessions, vacancies, and non-payment, as well as the average unoccupied units in a market.

Marketability: How a property fits into the market and its desirability relative to similar properties.

Migration: The movement of households into or out of an area.

Mixed income property: Properties with both income-restricted and unrestricted units, or with units restricted at different income levels.

Mobility: The ease of moving from one location to another within a market.

MOE (Margin of Error): A measure of uncertainty in ACS estimates, representing the 90% confidence interval around the point estimate.

Move-up demand: Estimate of consumers willing to relocate to more expensive or desirable units.

Multifamily: A housing structure with multiple separate housing units, such as an apartment building.

Neighborhood: An area within a city or town with common demographic and economic features.

Net rent: Gross rent minus tenant-paid utilities.

NOAH: Naturally occurring affordable housing. Market-rate housing that is affordable to low- and moderate-income households without public subsidy.

Organic growth: The natural increase in households over time, excluding growth from major new developments or projects.

Overcrowding: Housing condition where there is more than 1.0 person per room, excluding bathrooms, kitchens, and hallways.

PCHIP (Piecewise Cubic Hermite Interpolating Polynomial): An interpolation method that produces smooth curves while preserving monotonicity and avoiding oscillations.

Penetration rate: The percentage of qualified renter households all existing and proposed properties must capture to achieve stabilized occupancy.

Pent-up demand: A market with very low supply and vacancy rates.

PMI (Private Mortgage Insurance): Insurance required by lenders when down payment is less than 20% of home value, typically 0.5% of loan amount annually.

Population trends: Changes in population levels due to births, deaths, and migration.

PostGIS: A spatial database extension for PostgreSQL that enables storage and analysis of geographic data.

Primary market area: The main geographic area from which a property draws its residents.

Programmatic rents: Also known as restricted rents.

Project based rent assistance: Rental assistance allocated to specific properties or units, available to income-eligible tenants.

PUMA (Public Use Microdata Area): A geographic area containing at least 100,000 people, used for releasing census microdata while protecting privacy.

PUMS (Public Use Microdata Sample): Individual-level Census data with geographic identifiers no smaller than PUMAs, allowing custom tabulations.

Purchase price: The sale price of a home.

Redevelopment: The redesign or rehabilitation of existing properties.

Regional mover: A household that has moved into the region in the last 12 months.

Rent burden: Gross rent divided by adjusted monthly household income.

Rent burdened households: Households with a rent-to-income ratio above acceptable levels defined by lenders or programs.

Restricted rent: Rent charged under specific housing program restrictions.

Restricted rent, Achievable: Rents attainable considering market and income restrictions.

Saturation: The point at which no additional units are demanded in a specific market segment.

Secondary market area: An area that provides additional support to a property beyond the primary market area.

Single-family: A stand-alone housing unit detached from any other house.

Special needs population: Specific groups not typically served by conventional properties, such as those with disabilities or special requirements.

Stabilized level of occupancy: The expected number of occupied units a property maintains after the initial rent-up period.

Substandard conditions: Housing conditions considered unacceptable due to issues like inadequate facilities or overcrowding.

Substandard Housing: Housing units lacking complete plumbing facilities (hot/cold running water, flush toilet, bathtub/shower) or complete kitchen facilities (sink with running water, stove/range, refrigerator).

Subsidy: Income received to cover the difference between contract rent and tenant payment.

Target income band: The income range from which a property draws its tenants.

Target population: The specific group(s) a development aims to serve, often defined by state agencies based on income or demographic criteria.

Tenant paid utilities: Costs of necessary utilities paid by tenants, excluding cable, telephone, or internet.

Tenure: Whether a housing unit is owner-occupied or renter-occupied.

TIGER (Topologically Integrated Geographic Encoding and Referencing): The U.S. Census Bureau's geographic database that provides boundary files for all census geographies.

Townhome: An attached home as part of a larger structure, sharing walls with other units.

Turnover: The rate at which occupants change in a housing unit or property.

Unmet housing need: The need for additional units to accommodate growth, homeless individuals, or those in substandard conditions.

Unrestricted rents: Rents without any income or rent restrictions.

Unrestricted units: Units without any restrictions on income or rent.

Vacancy period: The time an apartment remains vacant and available for rent.

Vacancy Rate: Percentage of housing units that are vacant, calculated as vacant units divided by total housing units.

Vacancy rate, building: Metrics on potential versus actual rent revenue, and the proportion of habitable units that are vacant.

Vacancy rate, community: The percentage of available housing units that are vacant or unoccupied. A vacancy rate of 5-6% is considered healthy.

ZCTA (ZIP Code Tabulation Area): A generalized areal representation of U.S. Postal Service ZIP Code service areas, created by the Census Bureau for statistical purposes.

Zillow: Real estate database providing up-to-date for-sale and rental housing figures.

Zoning: Local government regulations on land use and density.