I think one thing missing here is you still need good cashflow to sustain the investment. 

I'm sure I don't need to explain to you the FHA self sustaining test for 3-4 units either.

They could care less about the effect on appeal but do care that they live in a space that is more sustainable and supports renewable energy.

Someone posted a very great mention about staying slightly under comps (as this helps keep up the good relationship with the tenant---because they feel they are getting a good deal) and it also gives you room to go up if you need to (for reasons outside of regular rental increases that sustain with inflationary demands).

The ROI that is quoted/projected on these to the syndication (funding partners) is often in excess of what the income could sustain/justify.

I like passive income sources that are sustainable business models.

Cash flow is a little tight, but appreciation has been healthy and sustainable.

We wanted to focus on building something more sustainable albeit with lower initial margins.

It is not a sustainable way to run a business nor is it an adviseable idea. 

This appears to have been working great for them, however at a great amount of management on their part.I knew up front that their current AirBNB type model would not work for me, and was not sustainable past a few more years (due to changing job markets in the area).