I currently have the treasurer of the board, who lives under neath one of my rentals, and will text me at 10:01 PM if he feels the TV is too loud from my tenant.  

They replaced all the flooring with padding underneath.

We just recently built an ADU from the ground up ~1100 sqft in Rosemead that cost us about $250k when all was said in done, this one requires a longer drawn out process such as soil tests, etc since you will be building framework from the ground up.

Predevelopment costs include site preparation, architectural designs, permits, soil tests, impact fees, property survey, utility trenching, land clearing and energy reports.

The age of the house, the location/market, expansive soils, ground water levels, and many other things can affect the answer. 

@Kelton Johnson  and were you live.. there is Hail and wind damage and your deductible and foundations.. every deal I have funded in your town had or has major foundation issues.. its not if its when .. and of course none of the location turn key companies mention this pesky reality of owning properties were you have major expansive clay soils.

American soil. 

I cut the flooring to the shape of the frame moding, and push it against the moding, instead of sliding underneath it.

We raise them 10-12 feet here, parking underneath.

It turned out that someone had tunneled underneath the ENTIRE house.