I would go with gas, it is more efficient and will save on cost long term.  

As a solar energy consultant for SolarCity I have been working with portfolio investors, helping them add value to their residential rental properties with clean solar energy, without tying up any cash flow.

This is becoming a popular option for cabins in the area to install, much more efficient than the baseboard heating many have and more practical than installing a propane system.My place: https://post.craigslist.org/k/tqTJaAlD6BGJPAqtBO1S...

It's a great strategy by having a larg amount of cash at once (when you sign off) and time off between ships to put your energy into investments.

I had to get my 3rd party manager set up with multifamily flooring, painting, and supply vendors and different maintenance so that turns would be faster, more efficient and affordable.

To be efficient, we'll be tearing down all existing framing, reusing just the foundation and 1st fl floor joists.

I came stumbled onto a company that are in the business special if you looking at houses using alternative energy.

I just hate to see all that energy put into such a low probability strategy.  

Developing is also another option, with a scale of doing 20-25 projects at a time, I think you can easily get a bank to give you a shot.Construction is not where I want to spend a lot of time and energy on.

I don't have experience with 1 but I believed they're more efficient than a furnace.We have a 2 flat with shared furnace as well.