My first house hack investment with reno in a high cost of living area

[Dasha Kosty]

I am closing on a multi-family (3-4 units) buy & hold investment in East Boston.

Purchase price: $969,000
Down Payment/ Closing Costs: $113,000

I am in the process of buying my first property, using a 2 for 1 buydown, which is in a non flood zone in East Boston. There are already 3 tenants bringing in a total of $7500 in rental income, if one moves out so I can owner occupy I make $5000. There is an unfinished basement which will likely be permitted to convert into an ADU but might trigger the installation of a fire sprinkler system ($30k). I was quoted $50k to renovate the basement. Does anyone know if the fire sprinkler system will be needed if I simply rezone the basement as part of the first unit? I am trying to figure out if it would be worth it to just bite the bullet and ADU the basement because of the appreciation that I will receive.

Interestingly, this property was on the market for over 100 days because the seller was firm on the price, but I was able to negotiate it down a bit. One of the units does have a minor infestation of brown wood cockroaches, but since they haven't spread to the other units, I'm hopeful they won't be too difficult to exterminate.