The project was to prepare a Request for Proposal (RFP) report and develop cost estimates to replace the hydronic heating and domestic water heating boilers in various buildings located at Marine Corps Air Station (MCAS), San Diego, CA. The second part of the project was to provide engineering study for solar thermal system of the domestic water. A design/build contractor will be awarded the contract to perform the installation work. Teza Design conducted a field investigation of the existing systems to provide the Design/Build contractor with guidelines and criteria according to unified Facilities Criteria (UFC), American Society of Heating Refrigeration and Air Conditioning Engineers (ASHRAE), International Plumbing Code (IPC) and International Mechanical Code (IMC). The existing domestic hot water storage tanks are to remain and to be reused. The solar systems are to be connected to the existing domestic hot water storage tanks and new boilers. Primary and secondary pumping system is to be utilized. The secondary main pumps are to be duplex type controlled by VFD responding to new pressure differential controller. The existing boilers, pumps, piping and flues and appurtenances are to be removed and replaced with adequately sized boilers and equipment, capable to carry the load. The hydronic boilers are to have a minimum of 85% efficiency and the plumbing boilers 92% efficiency. Where appropriate tank-less gas-fired water heaters are to be installed. Adequately sized bladder type compression tank with pressure reducing makeup valve, relief valve, make-up cold water pipe and associated backflow preventer on the make-up cold water line were specified. The vent stacks are to be long lasting with double walled stainless steel construction.