Land development costs for town homes apartments

[Curtis Eddie]

Splitting off 6 acres off my home 6721 strawberry plains pike Knoxville TN. I just rezoned it to 12 units per acre and can do apartments or town homes.... (hard to get zoning)I am a realtor and builder and have build 1 offs SFRs but this is a big step up. Does anyone have experience developing 6 acres and a range of the costs for roads and utilities? My land is mostly flat with just some dirt work needed and I have utilities to the sight. Looking at small starters 3/2 1 car 1200 sf range that I can build for 110k to a door but development costs I have no idea....

Also thoughts on buildings rentals to hold be town homes to sale? 60 to 70 units is prob to heavy on the 25% down payment for me to swing. Thinking specking the first 40 and trying to hold the rest?

Would love some thoughts