Investing in a property in Zilker area to rebuild

[Stef Martin]

We are looking to purchase an old home from the 50's in the Zilker area in Austin to tear it down and rebuild 2-3 homes on this large lot. My question is, in calculating comps what do I use for the comparables?  Normally I know that I would use similar homes recently sold.  But in this case, since we will only be needing the property and tearing down the home what do we use to: 1. come up with comps  2. develop my repair estimates.

My guess is that I need to find other older properties that have been bought, torn down and turned into multi-property homes in the area...

Any help would be greatly appreciated!