Subdividing two properties on one lot and selling them separately

[Sean Connolly]

I own a 3 Family property. On 1.4acres, there is one Duplex ( 2 1BR, 1BA) and a single family ( 3BR, 1BA) I bought the property for 315K. I have 305K left. I have seriously been considering subdividing the two houses. They currently share a well and septic. Both well and septic are on the duplex side, so I will have to put the new ones on the single family. The single family and one of the duplex units also share a driveway.

I was thinking, Put a new septic (15-20K), new well ( 5-10K) and redo driveway (10k???)

Ballpark quoted on $2000 for land surveying, fees, plans, and hand-ins to the town planning board.

A Duplex can go anywhere from 270-300K, and a single family can go for 230-270.

If my math is correct, am I really going to make possible over 100K for this deal? Or am I missing something big here? The pessimistic part of me is telling me its too good to be true.

[Sean Connolly]

Hey Richard,

 I was actually planning on writing a new post on it. The ups and downs of this deal is long enough to write a book on, but it eventually worked out. About 2 years longer and 30k+ over budget. 
I was able to subdivide. I sold the third lot and used it to pay down the mortgage. Originally bought for 319k. Sold land for 85k. By subdividing the two remaining houses, it dramatically increased the appraised value. One house appraised for 270k so I was able to put the remaining mortgage balance on that one and now the other house is mortgage free.