Housing Data

Home Values

Zillow Home Value Index (ZHVI): A smoothed, seasonally adjusted measure of the typical home value and market changes across a given region and housing type. It is a dollar-denominated alternative to repeat-sales indices.

Home Listings and Sales

Zillow provides data on sold homes, including median sale price for various housing types, sale counts (for which there’s detailed methodology), and foreclosures provided as a share of all sales in which the home was previously foreclosed upon. There are current and historical for-sale listings data, ranging from median list prices and inventory counts to share of listings with a price cut, median price cut size, age of inventory, and the days a listing spent on Zillow before the sale was final.

Rentals

Zillow Rent Index (ZRI): A smoothed measure of the typical estimated market rate rent across a given region and housing type. ZRI is a dollar-denominated alternative to repeat-rent indices. Details available in ZRI methodology.

Definitions

HOME TYPES AND HOUSING STOCK

• All Homes: Zillow defines all homes as single-family, condominium and co-operative homes with a county record. Unless specified, all series cover this segment of the housing stock.

• Condo/Co-op: Condominium and co-operative homes.

• Multifamily 2+ units: Units in buildings with 5 or more housing units, that are not a condominiums or co-ops.

• Duplex/Triplex: Housing units in buildings with 2 or 3 housing units.

• Top-Tier, Middle-Tier, and Bottom-Tier: Zillow Research classifies each home as bottom-tier, middle-tier, or top-tier by dividing the local housing stock into thirds based on the distribution of Zestimates (for value-based metrics) and Rent Zestimates (for rental-based metrics). Top-tier metrics are computed over only the top third of homes by value, middle-tier metrics are computed over only the middle third of homes by value, and bottom-tier metrics are computed over only the bottom third of homes by value.

TYPES OF ZILLOW HOME VALUE INDEX (ZHVI)

• All Homes (SFR, Condo, Co-op) ($): Typical home value for all homes of these types within a region.

• 1-Bedroom Homes ($): Typical home value for all homes with one bedroom within a given region.

• 2-Bedroom Homes ($): Typical home value for all homes with two bedrooms within a given region.

• 3-Bedroom Homes ($): Typical home value for all homes with three bedrooms within a given region.

• 4-Bedroom Homes ($): Typical home value for all homes with four bedrooms within a given region.

• 5+ Bedroom Homes ($): Typical home value for all homes with five or more bedrooms within a given region.

• Bottom-Tier ($): Typical home value for all bottom-tier homes within a given region. Bottom-tier homes are the homes that fall into the bottom third of home values within a given region.

• Top-Tier ($): Typical home value for all top-tier homes within a given region. Top-tier homes are homes that fall into the top third of home values within a given region.

• Condo/Co-op ($): Typical home value for all condominiums and co-ops within a given region.

• Single-Family Residences ($): Typical home value for all detached single-family homes within a given region.

• Median ZHVI per sq. ft. ($): Typical value of all homes per square foot. This number is calculated by taking the estimated home value for each home in a given region and dividing it by the home’s square footage.

RENT METRICS

• ZRI Multifamily, SFR, Condo, Co-op: Median of the estimated rent price for all homes and apartments in a given region, including those not currently listed for-rent.

• ZRI per Sq Ft ($): Median of the estimated monthly rent price of all homes, per square foot. This is calculated by taking the estimated rent price for a home and dividing it by the homes square footage.

• Median Rent List Price ($): Median of the price of homes listed for rent on Zillow in a given region.

• Median Rent List Price Per Sq Ft ($): Median of the rental price per square foot of homes listed for rent on Zillow in a given region.

OTHER METRICS

• Median List Price ($): Median of the list price (or asking price) for homes listed on Zillow.

• Median Sale Price ($): Median of the selling price for all homes sold in a given region.

• Median List Price Per Sq Ft ($): Median of list prices divided by the square footage of a home.

• Listings With Price Cut (%): The percentage of current for-sale listings on Zillow with a price cut during the month.

• Median price cut (%): Median of the percentage price reduction for homes with a price reduction during the month.

• Foreclosure Resales (%): The percentage of home sales in a given month in which the home was foreclosed upon within the previous year (e.g. sales of bank-owned homes after the bank took possession of a home following a foreclosure).

• Sale-to-List Price Ratio: Median of the ratio between the sale price and the list price for all homes (e.g. if a home with a list price of $200k sells for $250k, its ratio would be 5:4 or 1.25).

• Monthly Inventory: The count of unique listings that were active at any time in a given month.

• New Monthly Inventory: The count of unique listings that were newly listed at any time in a given month.

• Median Daily Inventory: Each Wednesday, daily inventory is calculated as the number of currently active listings. These counts are then aggregated into the number reported by taking the median across weekly values.

• Age of Inventory: Each Wednesday, age of inventory is calculated as the median number of days all active listings as of that Wednesday have been current. These medians are then aggregated into the number reported by taking the median across weekly values.

• Days on Zillow: The median days on market of homes sold within a given month, including foreclosure re-sales. The latest data is for one month prior to the current ZHVI (e.g., if the most current month for ZHVI data is January, the most current month for Days on Zillow data will be December).

• Home Sales: The number of homes sold during a given month. Note: ZIP code sales data is not latency adjusted, but is filtered.

• Home Sales, SA: The number of homes sold during the given month, seasonally adjusted using the X-12-Arima method.

• Zillow Home Value Forecast (ZHVF): The ZHVF is the one-year forecast of the ZHVI.

• Mortgage Affordability, Rental Affordability and Price-to-Income Ratio are calculated as a part of Zillow’s quarterly Affordability Indices. To calculate mortgage affordability, we first calculate the mortgage payment for the median-valued home in a metropolitan area by using the metro-level Zillow Home Value Index for a given quarter and the 30-year fixed mortgage interest rate during that time period, provided by the Freddie Mac Primary Mortgage Market Survey (based on a 20 percent down payment). Then, we consider what portion of the monthly median household income (U.S. Census) goes toward this monthly mortgage payment. Median household income is available with a lag. For quarters where median income is not available from the U.S. Census Bureau, we calculate future quarters of median household income by estimating it using the Bureau of Labor Statistics’ Employment Cost Index. The affordability forecast is calculated similarly to the current affordability index but uses the one year Zillow Home Value Forecast instead of the current Zillow Home Value Index and a specified interest rate in lieu of PMMS. It also assumes a 20 percent down payment. We calculate rent affordability similarly to mortgage affordability; however we use the Zillow Rent Index, which tracks the monthly median rent in particular geographical regions, to capture rental prices.