buying old rental properties

[Su Lee]

Hello,

thanks for all the information/knowledge you all share here. :) 

I'm new to MF investment, considering buying duplex in AZ.

I see many houses are built in 1950-70's and hear some folks saying they would not buy anything older than 1980's. 

I'm thinking old houses needs major repairs such as air conditioning/ducts/plumbing/hazard material removal (popcorn ceiling, asbestos, lead) if not done yet.  Is it true that it's better to avoid old houses and looking for houses built after 1980's?

Any advice will be appreciated.

Thank you!