Househack: do you calculate the lack of a mortgage into your ROI?

[Gabe Viteri]

Hi all, First steps out of the gate here, and I just wanted to get some input from the folks here that have been doing this for awhile.

I came across BP too late in the game and had already purchased a SFR. I now want to buy a triplex, house hack the other two units, and rent my SFR out. As an aside, I don't want to sell my SFR because I have a favorable HELOC that I plan to invest using the BRRRR strategy.

SFR

My existing mortgage is $2537 all-in. I can get $3k to rent this house. After I calculate my capex + vacancy + maintenance, I am -$70 a month. I will have to manage it on my own for a time, which I am okay with.

Triplex

The HouseHack Triplex after Capex + vacancy on the other two units + maintenance while I'm living there will be -$296 while I'm living there (1 year minimum for loan purposes), and +$1005 when I move out based on current rental rates.

Assuming all units are filled when I move into the Triplex, I am technically exchanging my $2537 mortgage for a $371 payment to own two properties. Here's my question, am I fudging the numbers if I use the balance of $2166 (2537 - 371) as a positive monthly number? I understand this is no longer an income, but it is more specifically a reduction of debt. 

How should I be framing this concept financially? It seems like the cost of inaction is very high.