The two dated starts
The Treasure Island Development Authority's Fall 2026 forecast, last updated on 14 September 2026, puts the behavioral health building on Parcel E1.2 first on its table. The estimated start is November 2026 and the estimated end is July 2028, at a value of $70 million.
The developer's own solicitation dates the same building more tightly. Mercy Housing California issued its request for proposals on 4 August 2026 and scheduled a construction start of 2 November 2026 with an anticipated completion in December 2028.
The authority's table projects the dates, and the developer's request for proposals schedules them. Both documents describe the same parcel.
What the parcel holds
The developer's document describes a 120-unit, 100 percent affordable residential step-down facility, a turnkey development to be owned by the San Francisco Department of Public Health. Mercy Housing California is the developer and owner, Cahill Contractors the general contractor, and Gensler and Paulett Taggart the architects.
The authority's row for the same parcel reads 240 treatment beds and supportive housing. The Mayor's Office release of 12 March 2026 sets 44 residential addiction treatment beds inside the building on a $14.2 million Proposition 1 award. The release describes a 64,000-square-foot, six-story building at Tradewinds Avenue and Mackey Lane that will also hold 172 Treasure Island beds relocated from former U.S. Navy housing.
The order behind the parcel
Three rows hold the earliest starts. Parcel E1.2 Senior adds 100 residential rental units from February 2027 to October 2028. Parcel IC4.3 adds 150 rental units from June 2027 to May 2029 under John Stewart Company and Catholic Charities, with Cahill as contractor.
The four remaining parcels belong to Treasure Island Community Development and carry TBD for general contractor with no published value. Parcel B1-B2 adds 117 rental units from 2027 to 2029. Parcel C2.3 adds 76 condominium units from 2027 to 2029. Parcel C2.1 adds 265 condominium units and Parcel C3.5 adds 160, both from 2028 to 2030.
The rooms the entitlement allows
The CEQA record for the project sets the entitlement at up to 8,000 residential units, 500 hotel rooms, up to 140,000 square feet of commercial and retail space, up to 100,000 square feet of office space and up to 311,000 square feet of adaptive reuse across three historic buildings.
The authority's forecast dates none of the lodging. Its preface states that the dates and values are projections, are not guaranteed, and are subject to change.
The demand the island already carries
Treasure Island Community Development has completed nearly 1,000 units in less than four years, about 27 percent of them below market rate (San Francisco Chronicle, 8 July 2026). Isle House, at 250 units, and Hawkins, at 178, both run above 90 percent rented. The Bristol, a 124-unit condominium building, runs about 70 percent sold.
Rents at 490 Avenue of the Palms run from $3,000 to about $9,000 a month, and the Palms Collection reaches $18,000 for a 2,250-square-foot penthouse. Eight parks are open across the two islands.
What a revenue team watches
Engine puts the San Francisco average nightly rate at $165 across 3.1 million public rate observations from May 2024 to April 2026. That figure ranks 18th of 50 markets and sits 11 percent above the $148 median.
The first keys on the authority's table belong to the 240 care beds on Parcel E1.2. Three items would put hotel rooms on a calendar: a contractor and a value on a commercial parcel, a lodging row on the forecast, and a named operator. Each carries a publisher and a date when it lands.