Even brand new homes do not (usually)..So you would have to demo the garage and slab and start over.

@Wei Jie Yang There's no one right way to do a partnership.

From there add the "approximate" additional costs for demo and prep, landscaping etc, and you would have your answer pretty quick.

We had an accepted offer when we just completed the demo.

Demo, framing, tiling, flooring, painting, cabinets, you name it. 

On deals where I purchased from the MLS, I either bought after another buyer did not perform and got a better price or I tore the house down and built a new larger one in a high end area where the cost at purchase was basically my land cost plus cost to demo and where I could build for under $200 pSF and resale for over $750pSF.

We have done a lot of the initial work (new foundation, demo, stabilizing the hillside, minor framing. 

I worked with Demo and Claudia Nunez of Tremont Realty Group.

It is usually one day for demo and 1-2 days to rebuild.

Maybe have them demo a load of clothes to see how wet they are coming out of the washer (not every person knows what the clothes SHOULD look like- it could actually be an issue with the washer).