Gardner Institute previews 2025 Utah city and town estimates; more than half of residents now in cities of 50,000+

The Kempsey Gardner Policy Institute, together with the Utah League of Cities and Towns, previewed the state’s 2025 city and town population estimates during an embargoed webinar, saying the new numbers show “2025 marked the first year that more than half of Utahns lived in a city with a population of 50,000 or more,” the institute’s researcher Megan Ravey said.

The estimates use a housing‑unit method that begins with 2020 census block counts and applies a 07/01/2025 municipal boundary file, building‑permit counts and adjustments for household size and group quarters to produce a July 1, 2025 point‑in‑time total for each city and town, Mallory Bateman, Director of Demographic Research at the Kempsey Gardner Policy Institute, said. The institute will publish a full table, a methodology guide, a fact sheet and an interactive web app on gardener.utah.edu when the data are released to the public.

Why it matters: the Utah Population Committee’s county estimates are now the standard reference in state code after recent legislation (HB 379), and the institute’s city‑level series has been produced so each subcounty area sums to those county totals. Natalie (Kempsey Gardner Policy Institute presenter) said the state’s first fully standardized, locally produced time series at the city/town level reflects extensive data validation and local inputs.

How the model works: the team translated building‑permit growth into household population using tenure, occupancy and census‑tract average household size, applied development‑size construction lags to estimate when permits become occupied units, and adjusted household totals so all places within a county sum to the Utah Population Committee county estimate. The process also incorporates updated group‑quarter counts—for example, college residence halls and nursing facilities—based on facility responses to the institute’s requests.

Quality checks: the presenters said they used roughly 110,000 building permits as inputs, filled gaps by collecting permits directly from 28 jurisdictions, standardized addresses to improve geocoding via the Utah Geospatial Resource Center, removed duplicate or ineligible permits, and conducted targeted reviews of large multifamily projects and short‑term rental markets. The team also produced 289 subcounty estimates and benchmarked them against Census estimates, prior years and other local data sources.

Key findings previewed: places with populations between 5,000 and 20,000 grew fastest between 2024 and 2025 at about 1.5%, compared with a statewide average of roughly 1.3%. The institute reported 172 communities gained residents in 2025, up from 151 the prior year. The top 10 growth communities are concentrated in Utah County, Salt Lake County, Washington County and Tooele County.

Differences from Census estimates: presenters said differences reflect several factors: the institute sources building permits from Construction Monitor while the Census Bureau uses the Census Building Permit Survey; model inputs differ (for example, the institute applies longer construction lags for large developments than the Census’s assumptions); and municipal boundary files are dated differently (the institute used 07/01/2025 boundaries vs the Census’s 01/01/2025), which can change time‑series values when annexations are applied retroactively.

Release and access: presenters said participants on the call would receive embargoed data and a memorandum later the same day and that the institute would hold a public data release and a media roundtable the following morning. Published products will include a time‑series table for every place, a downloadable dataset with additional variables, a fact sheet by community size, a methodology user guide, and an interactive web application.

The webinar closed with an invitation for communities to continue submitting building permits to the sources used by both local and federal estimators, and with organizers reminding attendees that the slides, recording and embargoed data would be distributed to registrants.