If I want to convert this sizeable space into 1 or 2 apartments, is there a tool or rule-of-thumb to use to estimate the costs of this project?

Always analyze comparable thoroughly and have a very good estimate for your rehab cost.

Always analyze comparable thoroughly and have a very good estimate for your rehab cost.

The above are conservative estimates.

Hello, This is my first time using the BRRRR calculator and I had to estimate some of the numbers since the property hasn't hit the market yet.

Ane,After getting the rehab costs estimated to the best of your ability, and If the numbers look like it will work, I recommend putting in the offer with a contingency based on inspection results.

How do people estimate rehab costs when driving for dollars for off market properties when all you ever see is the outside?

I estimate a realistic total lot value if done in 1/2 acre lots would sell on average for $65,000 or approximately $65,000,000. 

The email was one week before it hit the market and they were quoting him “estimated closing price: $ 6m.”

All that matters is buying distressed deals (hopefully below market price), properly estimating the ARV, accurately estimating rehab (you could crush this step!)