Way beyond me: Calculate ROI of home energy improvements... while also taking into account increases

[uberyes]

Hi,

I want to make an ROI energy improvements calculator.

I've got this far:

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Improvement Cost Saving per year
Cavity wall 750 150
Roof insulation 500 175

Total 1250 325

ROI: 3.8 years

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So far, so embarrassinly simple.

However, I'd like to add a bit more...

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Probable yearly energy price increase: 12%
Actual savings:
Actual ROI:
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Any thoughts?



Many thanks,

Uberyes

 

[Bernie Deitrick]

Uberyes,

=NPER((4%-12%),325,-1250)

The 12% is the assumed increase in energy costs, and 4% is the assumed loss of income if you had
otherwise invested the funds...

HTH,
Bernie
MS Excel MVP