Building a second home on my investment property? Modular home?

[Jamie Yeung]

Hello BiggerPocket Community,

I just purchased a multifamily home and there is a huge lot to the right of the home that came with my purchase. My home number is 10 and the neighbors are 6 so I assume that the lot in-between us is suppose to be 8. It is quite an odd plot of land as there is a random driveway so I assume it used to serve as an extra parking lot or maybe a trailer home in the past. 

I was curious if anyone has ever build a second home on their investment property. I don't even know where to begin... I assume I need to contact the county to see if anything can be build on that lot? Or do I hire a contractor to submit blue prints to the county for approval? 

Also, has anyone had experience with installing manufactured homes or modular homes? These seem like a way cheaper alternative to build on a plot of land and a good way to get cashflow by year 1 instead of going the traditional home construction route. I have heard that these homes don't last as long as traditional homes and depreciate in value pretty quickly.

Look forward to hearing for you all :)

Jamie