The heating, ventilation, air conditioning, and refrigeration industry shows a trend toward increased adoption of condensing boilers in heating systems, but the full impact on design and construction is complex. In design the selection of the boilers, heating coils, and operating temperatures play equally important roles in the composition of an efficient system. The failure to optimize design for a system as a whole can lead to wasted energy and money. This paper investigates the effect on overall system performance and construction cost of various heating system metrics with regards to condensing and noncondensing boilers.