Every lot at Promontory carries a single letter on its recorded subdivision plat, and that letter decides whether you can make the home your primary residence. An "E" or "ESBD" marks Estate Base Density. "ID" marks Incentive Density. "R" marks a Resort Unit. The letter comes from the 2001 Promontory Development Agreement. Summit County adopted that agreement as Ordinance 406 and recorded it against all property in the Promontory Specially Planned Area on February 27, 2001. A buyer who plans to spend a few ski weeks and part of the summer here can treat the three letters about the same. A buyer who may someday retire here, or claim the home for property tax purposes, cannot.
The letter is also set long before a buyer walks the lot. It gets assigned when the developer draws units from a fixed pool and the county approves the plat. As that pool shrinks, the mix of letters on the remaining land is what's left to choose from.
What "permanent" means in the agreement
The rules turn on one definition. Section 1.37 of the Development Agreement defines Permanent Occupancy this way:
"the occupancy of a Residential Unit within the Community for more than six months of a calendar year or where the owner has claimed a primary residential property tax benefit under applicable law."
The second half of that sentence catches people off guard. The agreement counts how long you stay, and it also counts what you file. Under the agreement's own wording, claiming a primary residential tax benefit counts as permanent occupancy, whatever your calendar looks like.
That benefit is a big one in Utah. The state's primary residential exemption generally excludes 45% of fair market value on qualifying property, up to one acre. Part-year property must be used as a primary residence for 183 or more consecutive days in the application year to qualify, and transient-use property is excluded. Summit County's application asks owners to declare primary, rental or non-primary status, requires every owner to sign, and asks for each owner's Utah driver license as proof of domicile. Nothing here is tax or legal advice. The point is that one county form connects directly to a Promontory plat note.
Three letters, three sets of rights
The plat notes on Hawks Pass Phase 2 lay out the full taxonomy in one place.
| Plat letter | How the lot qualifies | Home size on this plat | Path to full-time residence |
|---|---|---|---|
| E / ESBD, Estate Base Density | At least one acre, designated base density by the developer | 3,500 to 8,000 sq ft; up to 12,000 across two combined lots if the design reviewer approves | The plat notes attach no conversion fee |
| ID, Incentive Density | Lots that don't qualify as estate lots, or estate lots not designated base density | 3,500 to 8,000 sq ft; up to 12,000 across two combined lots if approved | One-time conversion fee to Summit County: $10,000 in 2001 dollars, CPI-adjusted |
| R, Resort Unit | Tightly clustered, generally on lots of a half acre or less | 2,500 sq ft of net livable area maximum; lots cannot be combined to add floor area | Not available |
Floor area at Promontory is measured as net livable area. It excludes wall interiors, garages and unconditioned storage or mechanical space. The 8,000-square-foot cap is written for this plat and may be tightened further by the Design Guidelines, so each new subdivision's notes deserve their own read.
The Incentive Density note also says all owners may be required to submit an affidavit declaring their permanent or part-year occupancy status. Summit County's August 18, 2026 staff report for the Eastern Sky subdivision still gives the fee as "$10,000 in 2001 dollars," subject to CPI adjustment, without a current dollar figure. A buyer who needs the exact amount should confirm it with the county before closing.
Converting an ID lot takes four stops
Summit County publishes the conversion route as a one-page sequence.
- Promontory prepares the Affidavit of Conversion to Permanent Occupancy on request. The county sheet names Morgan Reese at the club's Ranch Club Trail office as the contact.
- Summit County Community Development in Coalville reviews it.
- The Summit County Assessor's Office takes the application and proof of residency, and collects the conversion fee once the application is approved.
- The Summit County Recorder records the affidavit and returns a recorded copy to the Assessor.
The same sheet carries one line in capital letters: "RESORT UNITS DO NOT QUALIFY FOR A CONVERSION."
Resort Units are second homes by design
The Development Agreement defines a Resort Unit as "a dwelling located in the immediate vicinity of a hotel or club facility and offered for rent or overnight stay as a part of the operations of the hotel or club facility." The occupancy rule follows from that purpose. Resort Units are limited to short-term occupancy of no more than six months by any resident in a calendar year, and owners cannot qualify for permanent resident status based on owning one.
The draft Notice of Restrictive Use for Hawks Pass Phase 2 adds a backstop. If a court ever finds the occupancy limit unenforceable and an owner then uses the unit as a permanent residence, a $10,000 impact fee is payable to the county "regardless of whether the Occupancy Limitation in Section 4.4.1.6 is held to be legally unenforceable." The same notice is already Note 12 on the Clubhouse Villas Subdivision plat. County staff require a notice like this to be recorded against each Resort Unit specifically "to further inform future buyers."
For a buyer who wants an East-side club residence for ski weeks and summer golf, a Resort Unit can be exactly the right product. For anyone who might later want to live in the home year-round, the notice on title rules that out.
The pool is filling, and the letters are fixed at approval
The 2001 agreement set up a pool of 1,901 units: 885 estate base lots, 716 incentive density lots, and two hotels with 300 resort units, on about 6,500 acres with at least 3,900 kept as passive open space. County staff reports show how quickly that pool has been drawn down:
- June 2, 2025: 1,481 units approved, in the staff report for Horizon Point, 14 Estate Base lots off Painted Valley Pass. Scenic Valley went to the same hearing with 19 Estate Base and 6 Incentive Density units.
- October 2025 and February 2, 2026: 1,520 units approved, in the Hawks Pass Phase 2 staff reports for both meetings, an increase of 39 that matches those two subdivisions combined.
- August 18, 2026: 1,535 units approved, in the staff report for Eastern Sky, a nine-lot plat off Golf Club Link with 4 Incentive Density and 5 Estate Base units.
That leaves about 366 units of the original 1,901. The step from 1,520 to 1,535 matches the 15 units, 8 Estate Base and 7 Resort, that the October 2025 staff report assigned to Hawks Pass Phase 2, the subdivision south of the Nicklaus Clubhouse on a new ring road called Hawks Meadow Lane. The February packet's 23-unit figure would not produce that number. The match suggests the county approved the plat, although the records reviewed here don't include a final decision notice or recording entry for that plat or the two 2025 plats.
The letter on each lot is decided in this approval process, and the paperwork doesn't always get it right the first time. At the Eastern Summit County Planning Commission's July 16, 2026 hearing on Eastern Sky, staff told the commission that some lots' density types had been mislabeled as Estate Base or Incentive, which threw off the unit counts. The applicant was to submit a corrected plat before the County Manager's hearing.
Hawks Pass Phase 2 shows the same problem. TownLift reported in February 2026 that it would draw 23 units from the resort pool. The county's staff report for the February 2, 2026 meeting uses the same 23-unit figure. The October 2025 staff report gives 8 Estate Base and 7 Resort units. The draft notice names lots 10 through 16, seven lots, as Resort Units. The applicant's own narrative lists seven villas, six estate lots and two incentive density lots. When the public summaries don't agree, the recorded plat and the notice on title for the specific lot are the documents to check.
The rest of the plat notes affect the build budget
The same notes put costs and limits on a lot purchase that rarely show up in marketing. The Development Agreement requires a $3,000 agricultural preservation contribution to Summit County at lot purchase, and $500 for the county's affordable housing program at building permit. Both apply to Resort Units too. All roads in Promontory are private and maintained by the association. Driveways and lot landscaping are the owner's responsibility.
Site work is changing as well. County staff wrote that because disturbance per lot had been increasing, Promontory adopted a limit on grading within each building pad in its Architectural Guidelines, and that note now goes on all future subdivision plats. The Eastern Sky plat says it directly: home plans "must utilize existing grade to the greatest extent possible." The county has not published a numeric cap. A large pad no longer means you can level it for a flat-site floor plan, so the architect should see the plat notes before the purchase contract goes firm. Our guide to contingencies in Park City transactions covers how to build that review window into an offer.
A short FAQ
Does the six-month rule apply to every Promontory home?
No. The six-month cap on Resort Units is recorded against lots marked "R." Incentive Density lots can convert to permanent occupancy by paying the county fee. The plat notes attach no conversion fee to Estate Base Density lots.
Is there a limit on how many owners can live at Promontory full time?
In 2021, KPCW reported that the original agreement limited year-round residency and quoted then-general manager Kelli Brown as saying there was no current limit on full-time residents. That statement predates the 2025 and 2026 plats. Rights for any specific lot depend on its density letter. Brown has since become managing director, and Jonathan Fillman was named general manager in February 2026.
Where do I find a lot's letter?
It's on the recorded subdivision plat as a symbol next to the lot, and Resort Units also carry a recorded Notice of Restrictive Use. County staff reports and hearing packets, posted on the Utah Public Notice site, show the proposed allocation before recording.
What if I want full-time flexibility later but buy as a second-home owner now?
Then the letter is the first thing to check on any lot you're considering, ahead of the view or the price. An ID lot keeps the conversion option open for a fee. An R lot does not. Our notes on choosing between a second home and an investment property cover the broader version of that decision.
If you're weighing a lot at Promontory, I'm happy to pull the recorded plat and any notice on title with you, go through the density letter, the size caps and the grading notes, and line them up with how you expect to use the home over the next decade. Tara Vaught works through these documents with buyers before an offer goes in. Let's Connect.
