The ABCs of Mandatory Housing Affordability (MHA)

By: Alicia Teel Posted: 02/18/2019

A pathway to unlocking more housing options across our city

Aerial_Seattle_WideOver the next month or so, you’ll hear a lot more of the acronym MHA as City Hall considers legislation to address housing affordability, one of Seattle’s most pressing issues. An important part of addressing this issue is updating our zoning laws: currently, it is illegal to build even a duplex on 75 percent of the land zoned for housing in Seattle. MHA, which stands for Mandatory Housing Affordability, is a citywide proposal to address this.

The Chamber is engaged on this issue because high housing prices push people farther away from where they work – making it harder for our 2,400 members to recruit and retain workers. That’s why we are a proud member of the Seattle for Everyone coalition to support the Housing Affordability and Livability Agenda (HALA) recommendations a comprehensive package of affordable housing policies that will provide for a growing, inclusive city over the coming decades.

MHA is one of these policies and is simple in concept: to gain more development capacity, developers must provide affordable housing units within new buildings or contribute to a city fund to build affordable housing. The result in either case is more affordable housing. MHA is already in place in Downtown, South Lake Union and four other neighborhoods throughout the city and raised more than $13 million last year to create affordable housing.  

Putting MHA in place citywide will provide even more desperately needed affordable units in our city. Consider that had MHA been in place last year, we could have raised another $87 million worth of affordable housing without needing to raise taxes.



The Seattle City Council is considering the legislation in the Select Committee on Citywide Mandatory Housing Affordability. This Committee has been meeting for over a year and has held meetings around the city as it has considered this legislation.

City Council has three upcoming meetings:

  • February 21: Public hearing in Council Chambers at Seattle City Hall (600 4th Ave., Seattle)
  • February 25: Committee Discussion and Potential Vote on amendments
  • March 18: Planned Full Council Final Vote


The Council hopes to pass MHA legislation next month, but it’s a critical time for Council to hear from supporters of affordable housing. 

  • Share your support for Mandatory Housing Affordability with the Seattle City Council at
  • Attend the February 21 public hearing on MHA at 5:30 p.m. at Seattle City Hall (600 4th Ave, Seattle)
For more information, please contact Mackenzie Chase, the Chamber's senior policy manager.