Frequently Asked Questions
The comprehensive planning process is complex, fast-paced, and can be challenging at times. We're answering common questions below about U.S. Census data, growth targets, new state legislation, and more on a weekly basis.
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What’s the purpose of comparing city-level data for Sammamish with county- or state-level data?
Any instances of showing county or state data alongside city data is simply for the purposes of comparison. For example, it is helpful to see how different racial/ethnic populations have increased/decreased in Sammamish versus how the same group has changed over time in King County or Washington State as a whole.
It’s also important to note that growth projections and targets are established at the county level, so Sammamish will frequently be compared to or expressed as a proportion of King County throughout the project.
Why are there inconsistencies among population and housing unit estimates in U.S. Census data?
The U.S. Census Bureau administers both the American Community Survey (ACS) and Decennial Census. The ACS samples the population on an ongoing basis to make estimates about social, economic, housing, and demographic characteristics. The Decennial Census provides an official population count and is conducted every 10 years. Planning Commission members may find the ACS Basics Handbook and this U.S. Census Bureau webpage useful.
We use ACS data, rather than Census data, for housing and demographic analysis. Oftentimes there is a different population number with ACS data compared to Census data, and it doesn't make sense to mix data sets. Population totals and housing unit counts also differ depending on topic and data source (ACS, Census, Washington Office of Financial Management). Population and unit counts that deviate by a few hundred do not make a difference for policy making.
What else is important to know about Census data?
The data on the U.S. Census Bureau page for Sammamish comes from multiple sources: the Decennial census, which is still limited for 2020; ACS 5-year estimates; and ACS 1-year estimates. 1-year estimates are typically less reliable–especially considering the rapid changes cities like Sammamish have experienced over the past few years. For example, the 1-year estimate for 2020 and 2021 might show more instances of residents working from home, but the 2022 1-year estimate shows this number has slightly decreased.
Ultimately, all of the data are estimates. Some types of data are only available from certain sources like the 2020 5-year estimates which were mostly estimated pre-pandemic.
What data sources are informing the comprehensive plan update?
A preliminary list of references consulted for the forthcoming existing conditions report, which will inform various comprehensive plan elements:
U.S. Census Bureau, Decennial Census for 2000, 2010, and 2020
American Community Survey, U.S. Census Bureau, 5 Year Data, 2016-2020.
Transportation Planning Products (CTTP) using ACS Census Data
King County 2021 Countywide Planning Policies, December 21, 2021.
King County Regional Homelessness Authority, June, 2022.
King County Urban Growth Capacity Report, King County Growth Management Planning Council, 2021.
LEHD Employment Statistics (LODES), U.S. Census Bureau
U.S. Department of Housing and Urban Development FY 2022 Income Limits Documentation System
U.S. Department of Housing and Urban Development, Point-in-Time Counts and Housing Inventory Counts
Vision 2050 A Plan for the Central Puget Sound Region. Puget Sound Regional Council, October 2020.
How are changes in housing stock and population accounted for after annexation?
The U.S. Census conducts an annual boundary and annexation survey to determine the latest legal boundaries of local jurisdictions. Any Census or ACS data includes annexed areas in its counts and estimates the year after Sammamish finalized its new boundaries.
If it is relevant to the comprehensive planning process, we will conduct a geospatial analysis to determine the additional housing units and population in annexation or potential annexation areas (PAAs).
What does workforce and middle housing imply?
Workforce housing can include townhomes, duplexes, cottage housing, small apartments, and other forms of small multi-family housing that can provide more affordable homeownership opportunities to Sammamish’s median- and low-income households. Small-lot single-family homes can also be suitable for certain households. Subsidized units in these structures or larger apartment buildings may be among the strategies developed to expand workforce housing.
Exact policies and implementation strategies will be determined during subsequent phases and will reflect public feedback we gather during future engagement opportunities.
What new legislation will impact the comprehensive plan update?
The following Washington State legislation has been introduced in recent years and is expected to influence the update process:
HB 1220 - updated Growth Management Housing goal to “plan for and accommodate housing affordable to all economic segments of the population”, provide for middle housing, and address racially disparate impacts.
HB 1241 - requires larger counties and cities to submit an implementation progress report on key outcomes, including housing affordability and availability, permit processing timelines, greenhouse gas emissions, and vehicle miles traveled, five years after the review and revision of their comprehensive plan.
HB 1717 - requires local governments to collaborate with federally recognized tribes during planning efforts.
The Department of Commerce is updating administrative rules for the Growth Management Act and is expected to finalize rulemaking by December 31, 2022. Click here for an overview of possible rulemaking.