USACE SPK anticipates a potential requirement for design-build (DB) construction services to replace the existing heating, ventilation, and air conditioning (HVAC) system with a geothermal heat pump solution at the historic Hacienda building located at Fort Hunter Liggett (FHL) outside Jolon, California (CA). The 19,588 square-feet, 2-story building was built in approximately 1930, was placed in the National Register of Historic Places on 2 December 1977 and is currently used as a hotel. This project is anticipated to include:- Demolition and removal of existing mechanical, piping, plumbing, flue, electrical, architectural, structural, seismic, civil and controls equipment, as needed, to install the new geothermal heat pump system, water heaters and associated storage tanks.- Installation of a geothermal bore-field to consist of twenty-four (24) each 500-foot deep closed-loop vertical bores.- Underground geothermal headers feeding into the building. Pipes are anticipated to be emplaced underground to maintain the visual appearance of the historical structure.- Demolition of multiple domestic hot water heaters to be replaced by water connections for the new domestic hot water heat pump system and hot water storage tanks.- Installation of new geothermal heat pump console units.- Installation of new geothermal heat pump horizontal units.- Installation of new mechanical units to include seismic design category ?D? braces. This project is not anticipated to include fire protection. AMENDMENT 0001 - This amendment is being issued to add the following: NACIS: 238220 - PSC: Z2FB - SBA Size Standard: $19M - Magnitude of Construction is estimated to be between $1M to $5M. 2. Add Attachment 05 revised appendices 20250707. 3. Add Attachment 06 - Site Walk Sign In sheet 20250819. 4. Add updated WD CA20250018 - 20250822. All other items remain unchanged. Amendment 0002 is being issued for the following: 1. Proposal due date has been extended to 10 September 2025. 2. Spec section 01 10 10.07 DESIGN REQUIREMENTS - ARCHITECTURAL - Delete paragraph 1.5.3 Fire Extinguishing System in its entirety. 3. Spec Section 01 57 19 TEMPORARY ENVIRONMENTAL CONTROLS - a. Add to paragraph 1.5 Submittals: Well Drilling permit; G; b. Add a new subparagraph 1.12.6 Well Drilling permit: The contractor will be responsible for obtaining a well-drilling permit from the Monterey County Water Resources Agency. 4. Add CLIN OPTION 1002 - Hot Water Work. All other items remain unchanged. AMENDMENT 0003 - PROPOSALS ARE DUE 10 SEP 2025 @ 0900 HRS/09:00AM PST. ALL OTHER ITEMS REMAIN UNCHANGED.