However, the houses on the lots seem to be in such awful condition, it would probably be more efficient to demo the houses and re-build on the lots.

I will be conducting demos but don't want to skip something valuable or spend time on something people are hating. 

Most of my projects are new construction/heavy demo with major additions.

Additionally, the pandemic accelerated growth in relocation from northern cities to southern/southeast metros and the continuing trend of work from home looks likely to only continue those demo shifts. 

But he is taking some forms of demo debris.

http://www.biggerpockets.com/renewsblog/2013/04/11/bp-podcast-013-seller-financing-leon-yang/This podcast may help a bit.

Before we send out our demo crew we checked several times with this wholeseller (both their acquisition person and sales person) about the property being vacant and were given the assurance of it being vacant. 

Looking at buying a home in Philadelphia that needs some work and would appreciate some more experienced eyes going over the numbers.896 sqft 2/2:- Currently has central heat with gas furnace- Currently has no central airExpected construction and estimated cost:- Demo of central heat and new HVAC - 20,000- Complete demo and rehab of kitchen and two bathrooms 15,000 for kitchen 4,000 per bathroom- Finish basement 15,000- Flooring in bedrooms 3,000 - Interior paint 3,000- New W/D 5,000- Misc 10,000Estimated: +/- 80,000?

If you later demo the property, you do not recapture bonus depreciation on these items.

You'll eliminate the demo cost and time, as well as some of the material cost (1/4" vs  1/2" or 5/8").