I think it goes without saying though that there could be issues because of roof penetration if the system is installed by less than reputable solar installers - due diligence on these then is critical.

Embrace an expensive market by diversifying your options.

A few years back the city made the decision to embrace high rise structures, since than upscale high density condo and apartment construction has increased significantly, and there is more on the way.

The rain penetrated through the stucco and the wood frame siding got very wet. 

Area must have over 1 million people with mass transit/easy commute, area must have 80% workforce penetration either working or actively looking for work, and the area must have a vibrant tech based higher educational system.The cities are:BostonDallas (sorry Austin) PhiladelphiaHere is why I think these are the markets to beat and why others are not on the top three list.Pros:Boston has Harvard, MIT, Brown, BC, and UMASS is not far away either (Best).

I am sure concepts like AirBNB seemed crazy at first but now people are really starting to embrace it. 

In my market, I'm seeing an appreciation for this, so I'm embracing it.

If you only have piping penetrating the exterior walls it's a fairly small job.

While I knew I liked solving problems, it was embracing how much I valued my freedom that led me to discover working a job where your boss may or may not care about your opinions or what you wanted to do didn't work for me. 

Also, the city seems to embracing Airbnb rather than rejecting it.