How to account for "rent saved" on primary residence ROI

[Frankie Woods]

The debate rages on about the cons and benefits of buying a primary residence. As a military member, one of my primary strategies has been to purchase a primary residence with a low ( <5%) down payment and rent upon moving. Each period of living in a primary has averaged about 3 years. In the future, I'd like to increase my acquisition period to one year time frames. However, when calculating ROI and IRR, I've struggled with a way to account for the "rent" I'm saving. I'm curious if the community gives an income "credit" for "rent saved". For example, if I would pay, on average, $800/mo for a place to live for three years, would you include this in your overall return calculations. In my eyes, if I am accounting all expenses (e.g., settlement costs, maintenance, loan payments, interest, taxes), I should be able to include this phantom savings. This is not as critical for ROI, but is definitely important for IRR and XIRR. Thoughts?