The dollar amount of rent that is reported by available data sources varies greatly, with different estimates being designed to measure different things. In the report, we generally use Zillow’s Observed Rent Index to get the most recent information on how much landlords are requesting for their units and Census Bureau contract rent data to measure the amount current tenants are actually paying.

• Contract rent is the monthly rent agreed to or contracted for, regardless of any furnishings, utilities, fees, meals, or services that may be included. Data are from the American Community Survey (ACS).
• Gross rent is the contract rent plus the estimated average monthly cost of utilities (electricity, gas, and water and sewer) and fuels (oil, coal, kerosene, wood, etc.) if these are paid by the renter (or paid for the renter by someone else). Data are from the ACS.
• Fair Market Rents are estimates of 40^th percentile gross rents for standard quality units within a metropolitan area or nonmetropolitan county. Data are from the U.S. Department of Housing and Urban Development.
• The Zillow Observed Rent Index (ZORI) measures changes in asking rents for vacant units available to rent, regardless of the final contracted amount, controlling for changes in the quality of the available rental stock over time. Data are from Zillow Research.

Asking rents, as measured by the Zillow Observed Rent Index (ZORI), track the list price advertised by landlords, which may differ from the final lease amount. The types of apartments available for rent in a community at any particular moment can change markedly. To reflect actual movements in market prices, ZORI looks at price differences for the same rental units over time. 

Asking rents reveal the prices people encounter in the local market when they are actively searching for an apartment—whether they are renting for the first time, moving for work, or reentering the rental market after selling a home. High asking rents make it harder for young adults to get their own place, more difficult to move for a job, and less appealing for older adults, who might otherwise sell their home and downsize to an apartment.

Methodological notes about the Zillow Observed Rent Index can be found here: Methodology: Zillow Observed Rent Index (ZORI) – Zillow Research.

This measure compares the amount of income needed to afford typical asking rents to the actual current median income of renters in these cities. Following convention, rents are affordable when they do not exceed 30 percent of gross income. It is important to note that current asking rents are not the average amount paid by all current tenants in the city. Average rent among all renter households is typically significantly lower because of long-term leases and the fact that landlords will lower asking rents when they find that they have priced a unit too high.  

Housing affordability is not determined by rents alone—it is equally about the amount of income households have to pay them. Comparing asking rents to renter incomes is one indicator of how wide the affordability gap is in Gateway Cities. Asking rent burden also provides a leading measure to gauge how affordability is changing in the marketplace because the data reported by Zillow are much more timely than the data on all renter households that we receive from the ACS.  

Methodological notes about the Zillow Observed Rent Index can be found here: Methodology: Zillow Observed Rent Index (ZORI) – Zillow Research. Wage data are from 2023 ACS estimates and were adjusted upward to account for inflation. 

This measure uses ACS data to track the share of renter households that are considered cost-burdened or severely cost-burdened. A household is classified as cost-burdened if its members spend more than 30 percent of their income on rent, and as severely cost-burdened if rent consumes more than 50 percent of income. The estimates are based on five-year ACS averages. Combining years provides greater reliability for smaller geographies like Gateway Cities, but it smooths out short-term changes in rents and incomes. 

This measure captures what renters are actually paying for housing relative to their incomes, rather than what landlords are asking for newly available units. Because it reflects the lived experience of households who may be locked into leases or living in units below current market prices, it provides a more accurate picture of affordability pressures across the entire renter population. While asking rent data offer timely signals about conditions facing new entrants to the market, ACS cost-burden data show how deeply housing costs weigh on current residents’ budgets, and whether families have enough left over for other basic needs. 

The ACS is the source for all cost-burden estimates. Rent burden is calculated using gross rent, which combines the contract rent for which the tenant is personally responsible with estimated average monthly utility costs if paid by the renter. These figures reflect what households actually pay out of pocket. For households with Section 8 Housing Choice Vouchers or similar subsidies, ACS records only the tenant’s portion of the rent, not the total rent paid to the landlord. As a result, the data account for the role of these subsidies in lowering rents below market rates. 

The term “affordable housing” can mean different things depending on the context. The figures above quantify the rental stock of both naturally occurring affordable housing (NOAH) and deed-restricted affordable housing. 

NOAH refers to apartments that are affordable to households earning less than 50 percent of the state median income without any subsidy or income restriction. Few data sources attempt to quantify NOAH, yet doing so provides a fuller picture of the affordable housing stock across Massachusetts.  

Deed-restricted housing includes apartments reserved for low- and moderate-income households through legally binding use restrictions recorded on the property deed. While often called “subsidized housing,” not all deed-restricted units are produced with government subsidy—for example, some units are created through affordable housing set-asides required by inclusionary zoning ordinances.  

Standard measures of affordable housing often understate the stock available in Gateway Cities because they focus only on deed-restricted apartments. This approach makes sense in Greater Boston, where NOAH is scarce, but it distorts the reality in Gateway Cities, where NOAH has long been the backbone of affordability. By counting both deed-restricted units and NOAH, this measure provides a more balanced view of the housing options available to low- and moderate-income households. As NOAH is depleted, deed-restricted housing plays a growing role in preserving affordability. Equitable development ultimately requires a balanced mix of housing types across all communities. These figures provide a full view of how much affordable housing exists across the Gateway Cities.  

The ACS is the main source of data on NOAH. Contract rent for occupied units and asking rent for vacant units form the basis of our estimates. We then subtract deed-restricted affordable housing and households with mobile housing vouchers from the total number of units with asking rent or contract rent that are affordable for incomes below 50 percent of the state median. To deduplicate households with vouchers that occupy deed-restricted housing units, we assume that 26 percent of tenants of units subsidized with Low-Income Housing Tax Credits are using a mobile housing voucher to help pay their rent based on data from the Massachusetts Executive Office of Housing and Livable Communities and the U.S. Department of Housing and Urban Development. Vouchers were assumed to be distributed proportionally to the location of rental units. Note: Compared to the figures published in the 2024 Housing Monitor, the estimates presented here are significantly lower for the remainder of the state NOAH estimate. This is the result of improvements and corrections to the methodology used. 

Data collected by Housing Navigator Massachusetts provide detailed information on the supply of deed-restricted affordable rental housing across the state. As part of its update process, Housing Navigator also collects data on how much deed-restricted rental housing each community produces on an annual basis.  

Tracking changes in the stock of deed-restricted affordable housing is essential because these units provide the most durable guarantee of long-term affordability. Unlike NOAH, which can disappear quickly as markets shift, deed restrictions ensure that apartments remain accessible to low- and moderate-income households for decades. These data reveal the extent to which all communities are contributing their fair share of permanently affordable housing, a critical factor in addressing residential segregation by income and ensuring that families of different means have genuine options for where to live. 

Housing Navigator Massachusetts first began publishing this data in 2024. More information about tits methodology can be found here: https://housingnavigatorma.org/wp-content/uploads/2025/02/2501-Our-Data.pdf  

The Zillow Home Value Index measures changes in typical home value for homes in the 35^th to 65^th percentile range. These monthly figures provide another real-time indicator of how residential real estate prices are changing in different communities across the state. 

Tracking typical home values reveals how affordable—or unaffordable—it is becoming for households to enter the housing market. In Massachusetts, where prices have risen steeply, changes in home values directly affect whether moderate-income families can realistically pursue homeownership or are locked into the rental market. At the same time, persistent gaps in values between Gateway Cities and their suburbs reflect long legacies of disinvestment and redlining. Monitoring these differences highlights not only where affordability pressures are most acute, but also whether communities historically left behind are catching up—or falling further behind—in today’s housing market. 

Methodological notes about the Zillow Home Value Index can be found here: Zillow Home Value Index Methodology, 2023 Revision: What’s Changed? – Zillow Research  

This indicator estimates the share of households in each Gateway City that can afford to buy a home in their community. It combines Zillow’s measure of typical home values with ACS income distributions to calculate the share of households that is able to carry a new mortgage at current prices and interest rates. 

Measuring the share of households that can afford to buy in their own city shows whether local housing markets provide realistic pathways to homeownership. Because owning a home can stabilize housing costs and support long-term residency, this measure helps assess whether residents can remain in their community and build wealth as prices rise. 

Affordability is modeled using a 30-year fixed-rate mortgage with a 3 percent down payment at the prevailing 2025 interest rate of 6.69 percent. Monthly costs include principal and interest, property taxes based on city-specific 2025 rates, and homeowner’s insurance premiums equal to 0.3 percent of home value; private mortgage insurance is excluded. Because incomes are measured from 2023 ACS 5-year estimates adjusted for inflation to 2025 dollars, they may not fully capture recent changes in income. Results are benchmarked against Zillow’s measure of typical home values, meaning that they reflect the financial feasibility of buying a representative home rather than the number or type of homes actually for sale at affordable amounts. Methodological notes about the Zillow Home Value Index can be found here: Zillow Home Value Index Methodology, 2023 Revision: What’s Changed? – Zillow Research   

This measure draws on Massachusetts’ Subsidized Housing Inventory (SHI), the official list used to track compliance with Chapter 40B’s requirement that at least 10 percent of a community’s housing stock be affordable to low- and moderate-income households. The SHI includes both rental and ownership units that meet state affordability criteria, though deed-restricted affordable ownership units are relatively rare. Because entire developments are added to the SHI if they meet a minimum set-aside—typically 25 percent of units affordable at or below 80 percent of area median income, or 20 percent at or below 50 percent of area median income—not every unit listed is actually affordable. At the same time, not all affordable units have been added to the SHI, making it an imperfect but still valuable source of information on affordable homeownership. 

Producing affordable homeownership units opens doors for lower-income households to buy into their own communities—an especially important intervention in Gateway Cities, where ownership may look attainable on paper but remains out of reach for many residents with modest incomes. These homes provide residents with a foothold in the housing market, offering stability and a pathway into the middle class. They can also help balance the tenure mix in rental-heavy neighborhoods, strengthening communities and reducing displacement pressures. And even as deed restrictions expire at different rates, the public investment can leave a lasting imprint when they create ownership opportunities where they would not otherwise exist. 

The SHI is only required to be updated every two years, and data for 2025 are not yet available. For this reason, the figures reported above are the same data presented in the 2024 Housing Monitor. More information about the SHI inclusion criteria and update process can be found here: https://www.mass.gov/doc/guidelines-gl-c40b-comprehensive-permit-projects-and-subsidized-housing-inventory/download