flexiblefullpage -
billboard - default
interstitial1 - interstitial
catfish1 - bottom
Currently Reading

Conversions of multifamily dwellings to ‘mansions’ leading to dwindling affordable stock

MFPRO+ Research

Conversions of multifamily dwellings to ‘mansions’ leading to dwindling affordable stock

New York City has lost more than 100,000 homes since 1950 to conversion projects.


By Peter Fabris, Contributing Editor | September 11, 2023
Image by David Mark from Pixabay
Image by David Mark from Pixabay

Small multifamily homes have historically provided inexpensive housing for renters and buyers, but developers have converted many of them in recent decades into larger, single-family units. This has worsened the affordable housing crisis, say researchers.

These buildings, commonly called “triple-deckers, two-flats, or brownstones,” provide historical context and add character to urban neighborhoods along with affordability. Nationwide, low-cost rentals have vanished by more than half a million units per year between 2014 and 2018, according to a report from the Harvard Joint Center for Housing Studies (JCHS). New York City alone, lost more than 100,000 homes since 1950 due to conversions of multifamily buildings into single-family “mansions,” according to a report by Dwell.

Many of these buildings supply what is termed “naturally occurring affordable housing (NOAH)”—unsubsidized units rented at relatively low rates. A 2021 McKinsey report found that NOAHs constitute the nation’s largest category of affordable housing units, and that has prompted legislative action to preserve them in some cities.

For instance, in 2021 Chicago’s city council passed two ordinances to discourage developers from eliminating NOAH in two neighborhoods. Developers face up to $15,000 (or $5,000 for each lost unit) for tearing down or converting multifamily buildings.

Preserving older NOAHs takes more than laws, though, it requires someone to spend money to keep them in working order. According to a recent JCHS report, the median unit in small multifamily structures was built 54 years ago. That’s nine years older than the typical single-family home. NOAHs also “face significantly higher quality and structural issues” than your average single-family house, the JCHS report says.

Related Stories

Giants 400 | Dec 20, 2023

Top 40 Student Housing Construction Firms for 2023

Findorff, Juneau Construction, JE Dunn Construction, and Weitz Company top BD+C's ranking of the nation's largest student housing facility general contractors and construction management (CM) firms for 2023, as reported in Building Design+Construction's 2023 Giants 400 Report.

Giants 400 | Dec 20, 2023

Top 30 Student Housing Engineering Firms for 2023

Kimley-Horn, Wiss, Janney, Elstner Associates, KPFF Consulting Engineers, and Olsson head BD+C's ranking of the nation's largest student housing facility engineering and engineering/architecture (EA) firms for 2023, as reported in Building Design+Construction's 2023 Giants 400 Report.

Giants 400 | Dec 20, 2023

Top 90 Student Housing Architecture Firms for 2023

Niles Bolton Associates, Solomon Cordwell Buenz, BKV Group, and Humphreys and Partners Architects top BD+C's ranking of the nation's largest student housing facility architecture and architecture/engineering (AE) firms for 2023, as reported in Building Design+Construction's 2023 Giants 400 Report.

MFPRO+ News | Dec 7, 2023

7 key predictions for the 2024 multifamily rental housing market

2024 will be the strongest year for new apartment construction in decades, says Apartment List's chief economist.

Student Housing | Dec 5, 2023

October had fastest start ever for student housing preleasing

The student housing market for the upcoming 2024-2025 leasing season has started sooner and faster than ever.

Industry Research | Nov 28, 2023

Migration trends find top 10 states Americans are moving to

In the StorageCafe analysis of the latest migration trends, each U.S. state was looked at to see the moving patterns of people in the last few years. These are the top 10 states that people are moving to.

MFPRO+ News | Nov 21, 2023

California building electrification laws could prompt more evictions and rent increases

California laws requiring apartment owners to ditch appliances that use fossil fuels could prompt more evictions and rent increases in the state, according to a report from the nonprofit Strategic Actions for a Just Economy. The law could spur more evictions if landlords undertake major renovations to comply with the electrification rule. 

MFPRO+ News | Nov 21, 2023

Underused strip malls offer great potential for conversions to residential use

Replacing moribund strip malls with multifamily housing could make a notable dent in the housing shortage and revitalize under-used properties across the country, according to a report from housing nonprofit Enterprise Community Partners.

MFPRO+ News | Nov 21, 2023

Renters value amenities that support a mobile, connected lifestyle

Multifamily renters prioritize features and amenities that reflect a mobile, connected lifestyle, according to the National Multifamily Housing Council (NMHC) and Grace Hill 2024 Renter Preferences Survey.

Industry Research | Nov 17, 2023

Air conditioning amenity sees largest growth in Pacific Northwest region

The 2024 Renter Preferences Survey Report sheds light on the demographics, lifestyle, connectivity needs, and more for the renters of today. At the top of this list—the feature that respondents are “interested in” or “won't rent without”—is air conditioning.

boombox1 - default
boombox2 -
native1 -

More In Category


MFPRO+ Special Reports

Top 10 trends in affordable housing

Among affordable housing developers today, there’s one commonality tying projects together: uncertainty. AEC firms share their latest insights and philosophies on the future of affordable housing in BD+C's 2023 Multifamily Annual Report.



halfpage1 -

Most Popular Content

  1. 2021 Giants 400 Report
  2. Top 150 Architecture Firms for 2019
  3. 13 projects that represent the future of affordable housing
  4. Sagrada Familia completion date pushed back due to coronavirus
  5. Top 160 Architecture Firms 2021