Proper duplexes vs re-muddled single families

[Craig Shrimpton]

All,

I've been looking at 2-4 unit multi-families and I'm contemplating the relative merits of proper duplexes (houses built specifically as multi families) vs split-up singles. 

The re-muddled single families I've seen scream bad plumbing, bad electric, bad heating systems (usually one for the entire building) and generally high maintenance. The duplexes (trips and quads included) seem simpler in construction which should lead to easier maintenance.

They also seem like they would be easier to sell as they offer an owner the opportunity to live in one unit and rent out the other. However, that unfortunately seems to be the trouble with them as well. They are usually not priced the same as non-owner occupied investment property and often have anemic cash on cash returns.

Any opinions on whether the lowered maintenance costs are worth the lower returns? Are proper "plexes" a better deal/investment than converted single families?

Note that it is my impression the maintenance is lower due to factors such as no need for house electric, tenants shovel their own driveway and mow the lawn, more straightforward construction and usually better designed heating systems. If this impression is incorrect, let me know.

Thanks,

Craig