Subdividing Land in Salt Lake County, Utah

No subdivision is legal here without a recorded final plat

Salt Lake County's code is explicit on this point: no person may subdivide any tract of land within the jurisdictional limits of the unincorporated county unless and until a final plat, prepared in accordance with Title 18 of the County Code of Ordinances, has been reviewed and approved by the county's land use authority and recorded in the office of the Salt Lake County Recorder. In practice, that means an informal lot split -- dividing a parcel by deed alone without going through this platting process -- is not a legally recognized subdivision in the unincorporated county, whatever a seller or prior owner may have represented.

Title 19 of the county code (zoning, covered on our main county hub) tells you what a resulting lot can be used for and how large it has to be; Title 18 is the separate title that governs the actual subdivision and platting process itself. Both titles matter for a subdivision project, and they're administered by the same office.

The process: preliminary plat, agency review, technical review, then final plat

A subdivision request in unincorporated Salt Lake County requires review and approval of a preliminary plat first, followed by a Technical Review of the Final Plat. An Agency Review Meeting -- coordinating input from the relevant county and utility agencies on a single application -- is a required step in that process, and an engineering review of both the preliminary and the final plat is required before either can be approved and, ultimately, recorded. This is a multi-step, multi-agency process rather than a single planning-department sign-off, which is part of why subdivision timelines in the county can run longer than a buyer might expect from a smaller, single-department rural county.

Because unincorporated Salt Lake County's day-to-day planning, zoning, and building services are provided by the Greater Salt Lake Municipal Services District (MSD) rather than a conventional county planning department, MSD is the office that actually runs this preliminary-plat, agency-review, and final-plat sequence -- not the county's longer-range Office of Regional Development, which leads countywide plans like the West General Plan but doesn't process individual subdivision applications. MSD also publishes the current fee schedule for subdivision review and recording, which should be confirmed directly since fees are adopted and updated annually.

If your parcel is anywhere near the Kennecott-owned west side

Our county hub covers how Rio Tinto Kennecott's large west-side landholdings are mostly being master-planned and annexed into incorporated cities like South Jordan rather than subdivided and sold as individual lots under the county process described here. If a parcel you're evaluating sits near or within a Kennecott-held or recently-annexed area, confirm with MSD and the relevant city whether the land is still subject to Salt Lake County's Title 18 subdivision process at all, or whether it has already been annexed into a city with its own separate subdivision ordinance -- annexation changes which government's subdivision rules (and plat-review process) actually apply.