Any aging components should have be replaced so the investor shouldn't have major cap ex for the first 5-7 years.

Ultimately, the property is mine so I don't want to risk components breaking down and costing a lot more later because I expect the tenant to take care of it.

just fyi:  there's a TIME component to CoC. 

As mentioned above, they do a great (fabulous) job with their education component as well as with their networking component, which allows investors on the borrow and lend side to network.

And of course, if economics is not the only play, there's the environmental factor that is good for our own conscience and could be marketed to a tenant who cares about this stuff.One good thing that solar does is, whether you decide to go solar or not, is that you will be on a path to make the houses more energy efficient; better weatherization, stop leaks, better insulation.

It has 0 VOCs, which keep the odors down and is more environmentally friendly than many.  

I think the best and most objective source to date is the PWC Emerging Real Estate Trends report.There are reasons I chose not to go with Austin, Atlanta, and other hot markets of the sort after looking deeper into the environmental factors.

The businesses are related but two different components.  

The environmental ones are the ones that can get out of control: mold, lead, and asbestos.  

If you are thinking about breaking out the cost of individual structural components to depreciate separately, that won't get you anywhere because the depreciation class life for the structural components of a residential rental property is the same as the class life of the dwelling structure itself.