St. John’s Medical Center’s new expansion plan is 21 percent smaller than the original, according to a letter project architects sent to town staff.

Hospital officials have revealed little about the revised plans since submitting them to the state March 30. The letter from Hawtin Jorgensen Architects to Town Planner Tyler Sinclair offers the first glimpse of how the expansion has been trimmed since construction stopped in November 2011.

The letter precedes a presentation hospital officials will make before the Jackson Town Council during a workshop at 3 p.m. Monday. Town staff said the changes are minor, since they are reductions, and do not need to be approved by the town.

The original expansion plans called for roughly 28,000 square feet of renovations and 25,000 square feet of additional space for the oncology, obstetrics and surgery departments.

The recent letter outlines 18,800 square feet of renovations, a reduction of 9,200 square feet, and 23,200 square feet of additional space, a decrease of 1,800 square feet.

The hospital proposes reducing the area for a central energy plant, taking it from 5,000 square feet to 4,700 square feet. The plant would be set at the rear, or north, of the property.

While the plant construction will run concurrently with renovations and additions, hospital staff see it as a separate project.

St. John’s COO Gary Trauner said the size of both projects could change because costs have not been finalized.

The existing 258,500-square-foot facility sits on 16.32 acres in east Jackson, according to town documents.

Hospital officials will have a better grasp of costs when J.E. Dunn, the project’s construction manager, opens subcontractor bids at 9 a.m. Tuesday. Sub-contractors have until 5 p.m. Monday to submit bids.

Contractors are bidding on specific portions of the larger construction project, such as drywall and wiring.

Local and out-of-town contractors are submitting bids, Trauner said.

J.E. Dunn will organize the information in the bids so that cost estimates from subcontractors can be compared accurately.

Based on the information provided by J.E. Dunn, the hospital board’s facilities committee will recommend a subcontractor for each phase of the project.

The board plans to hold a public meeting at 4 p.m. July 5 to approve the chosen subcontractors and establish a maximum price for the project. Construction could then begin July 9.

St. John’s halted the project in November 2011 when price estimates came in $2 million to $3.5 million higher than expected. Architects drafted revised plans, which could receive final approval from the state in the next week, Trauner said.

The board will want a maximum price close to $25.9 million, which was the initial cost estimate for the project, Trauner said. Funds from the specific purpose excise tax will pay for $11.75 million of the renovations and additions.

While the central energy plant construction will run concurrently with renovations and additions, it will not be funded with SPET money, hospital staff said.