As an approach to evaluating an investment, would you agree that changing that variable - ideally into a cost segregation study using *actual* lifespans for components - would give you your expected Capex that should be planned for?

I'm actually interested in repeating this approach with future rentals, as I love to be environmentally friendly and imagine solar panels becoming more trendy in the future. 

I can stomach being stuck in a deal for many years with no cash flow and pathetic returns, but I can't stomach losing all my money due to optimistic underwriting.My current thought is to only enter deals that have longer term loans in place and would be able to hold for a long time if necessary without bank calls, do business with syndicators that rode out 2008 with stellar track records, only do deals that have some sort of value add component, and that have a "story" of how/why the deal is notably better than what an average market deal would be.

And also unlikely that it spilled enough oil into the soil to really be an environmental problem for that small property.  

Even in the US, rehabs vary greatly in price from one region to another, but it's a great book for understanding all the various components of a property, including the lifespan. 

The actual measure is EFFORT, of which a huge component is MARKETING BUDGET.  

Right now, I'm more concerned with long term cash flow potential viewed as a component of ROI, rather than what a property might be worth in 25 years. 

You do need some legal advise and you might go to someone who is well versed in environmental issues or look for someone who has dealt with dams/water issues, that is the closest I would imagine getting to owning a lake bed.

You can then set up an LLC to outline the agreed upon terms/structure and lenders will look at both of your credit and personal financial situations in making loan decisions.The split can be done a number of different ways, but what I would suggest doing is looking at all of the key components to a property and determining what those pieces are worth to you and your partner.  

This is important because if they process dry cleaning on premise there could be environmental issues.