In economic terms, a building design is deemed to be cost-effective if it results in benefits equal to those of alternative designs and has a lower whole life cost, or total cost of ownershipFor example, the HVAC system alternative that satisfies the heating and cooling requirements of a building at the minimum whole life cost, is the cost-effective HVAC system of choice. Components of the whole life cost include the initial design and construction cost, on-going operations and maintenance, parts replacement, disposal cost or salvage value, and of course the useful life of the system or building.