If you need to know for certain, the best way is to have a core sample made of a few locations around the construction site.  

@Kim Pham  However do not take our on line research as gospel.. it would be a good learning exercise for you to jump in your vehicle.Drive up the 101 to Santa Rosa go into the city planning department show them your plat map and ask them what can be done with the lot if anything. 

Sure, this vehicle will work, however you are suggesting that you will be improving the property before you exercise your purchase rights.

After remediation hire a home inspector to come into the home and perform an air sample test, which will give you an  idea what types of mole are present and what the levels are.  

When we compile our data scraped from Kijiji, we find the deviance of the medians and average to be within 4 - 8% ... much of that noise is likely due to our sample region being a little tighter and more selective than theirs.I particularly like to use CMHCs historical data when analyzing (aka debunking) pro forma and memoranda of offering we receive.Even where we can command rent 10% or 15% over market, we make certain we can operated profitable at 5 - 10% below market.

I'm not saying be open to purchasing a strip mall or doing new construction, but go through the exercise of doing a detailed evaluation of a deal on a 2 or 3 or SF home you could buy now.  

You will definitely want a certified company to do the work and a certified hygenist to do air sampling to confirm the mold had been remediated.

Sometimes the fireman will use the old houses as a controlled burn exercise for training and then you pay someone to just scrape the land.

That's an exercise in frustration. 

I will admit that this was mainly an exercise for myself to see if I am analyzing this all right.