Created en suite bed/bath, extra bedroom/office/playroom, created family/tv room, added a couple of windows in dark rooms, installed new HVAC, ran all new pex lines/valves/shut offs, all new hardwood flooring and carpet, all new and expanded kitchen cabinets, new appliances, converted 1/2 bath into full bath, repurposed 2 unused rooms (1 into a 4th bedroom/office/playroom and one into a family room, installed new interior and exterior lighting, new electric garage door w/remote, and landscaping What was the outcome?

Trust me, I've toyed with the idea.Vacant land where it makes sense to build large MFH stock might make sense, but chances are this isn't the land we're talking about here.The reality is most vacant land in Detroit is being repurposed for parks, the Joe Luis Greenway, solar farms, neighborhood gardens, etc.Beyond that, let's say you plan to hold long enough for SFH prices to get high enough where it does make sense to build. 

I presume it would be advantageous for my in-laws to pay back that $250,000 in multi-year installments to limit their capital gains tax liability? 

Once was installing a new microwave. 

Technically I believe you're covered if there is an accident because they were correct at the time they were installed.

Solar on main house. 

I have a tenant that wants to install a fence in the backyard of my property for their dog.

The electric company installed the new meter for free after giving me a credit for adding laying the conduit required for the 200amp to 400amp upgrade.As for the 1/2" (non fire code) gyp, my understanding of the code is that a 1 hour rated assembly is required between "dwelling units."

-Install a New Mailbox: Replace your old, worn-out mailbox with a new, stylish one that matches your home's aesthetic.

I owner-financed a small property in Ridord, PA that is under an installment contract or contract for deed for 15 years starting Sep 2015.