Hello BiggerPockets Community,TL;DR: Looking to house hack up to 4 units in NJ/NY using FHA loan + 203(k) rehab, can handle 3.5% down payment + closing costs on my own (+/- $100k-$150k)I’m a new investor in my early 30s looking to dive into the real estate market with a strategic approach.

I would like to legalize it and was wondering if anyone would be able to give me a rough estimate of the cost to convert the property to a 3 family.It does not have a sprinkler system. 

A mold specialist will cost you and arm and a leg and likely recommend unnecessary repairs.

The 'shovel-ready' value add will be a compelling feature but could cost a lot.

It has been shown to drive the cost of renting up for new tenants. 

They suggested while the property is vacant it is easier to repair, which costs 10-15k. 

I do not have much knowledge on real estate but I am the hitting  books: BRRRR by David Greene, Estimating Rehab cost by J.Scott, Investing real estate with no/low money down by Brandon Turner and finally, Rental property investing by Brandon Turner.Outside of real estate, I enjoy swimming, bike riding, watching anime, playing video games and interests in the stock/house market.Excited to learn and connect with you all!

But when I got my first bill from the attorney for 3000K+ I started to worry about how high legal costs could get even if they buyers dont win.

Cost segregation is a popular tax deferral strategy and there is often confusion as to the difference between bonus depreciation and reclassification.Bonus DepreciationBonus depreciation is a tax incentive that allows a business to immediately deduct a large percentage of the purchase price of eligible assets, such as washers and dryers, rather than write them off over the "useful life" of that asset.

Cost is mostly legal, with about $10K - $15K being average.