SIR: Savings to Investment Ratio
A ratio used to determine whether a project that aims to save money in the future is worth doing. The ratio compares the investment that is put in now with the amount of savings from the project. SIR takes the total energy savings over the lifetime of the improvement (Present Value) divided by the upfront cost of the investment. This calculation may or may not include increases in energy prices or inflation rates.
Lifetime Improvement Chart
This set of lifetime measures is applicable only for the State of New York, and determined by selecting the State of NY for the homeowner's address when creating a new job.
Attic: 30
Ceiling: 30
AirSealOnly: 20
Walls: 30
Door: 20
Windows: 20
Floor: 30
BsmtSlab: 30
Crawl: 30
Thermostat: 11
SealDucts: 20
Heating: 20
Cooling: 15
CFL: 7
Refrigerator: 17
Freezer: 15
DHW: 15
Dishwasher: 15
ClothesWasher: 15
We set the lifetime for heating systems in general to 20 years, but we currently have no way to set it to 25 years if it’s a boiler.