Here's a list I found for starters: http://www.missouribotanicalgarden.org/sustainability/sustainability/sustainable-living/at-home/hpwes/for-homeowners/find-a-contractor/st.

Slowing job growth in Central Texas, the impact of Hurricane Harvey on the price of building materials and housing development costs, and the overhaul of the U.S. tax plan are all factors that could hinder housing market growth and negatively impact housing affordability in the Austin area in 2018.”The ultimate outcome of the CodeNEXT process are still largely unknown:“2018 will be an incredibly important year in determining the future health and sustainability of Austin’s housing market and its communities,” concluded Guthrie.

I am currently in the process of doing some upgrades to the town house I bought last year.My main interests are adding 'green' and sustainable upgrades to homes and then renting them out.

My ultimate goal is to one day either have enough cash flow to be able to "retire" from my normal 9-5 job and do REI full time, or at least be able to have a sustainable cash flow for retirement. 

I realize this will not be sustainable as I get more properties.

Venture deals for early-stage startups and small real estate projects from unproven promoters with shorter track records will be what is available to the people least able to sustain the losses.  

I have friends who buy and hold here and they are having trouble maintaining rents.That said, if a deal works fundementally - can sustain cashflow, decent Cap rate, IRR, etc - then why not invest.

That's a number that I've seen sustained in my market over and over again, and if I'm inside that range at the end of the day I'm a happy man.That's not to say that I haven't had some serious partying going on when I've knocked it out of the ball-park and made 28%... or done the 'walk of shame' out of the attorney's office when I've made 5% (or worse)To answer your last question... yes, my number holds true across the price ranges.

Trouble is that's not a sustainable model.

Is this sustainable?