If he wants the building to demo and redevelop, then he can choose to let his units stay vacant (or put some tenants in - this scenario works either way) and then let the building deteriorate until the other units are undesirable for rentals and devalued for purchases.  

They are wanting to stay longer but want to also buy a house in the upcoming year.

Once you find the right fit, it's best to stay with that relationship, but when you're getting started, recommend putting in some legwork to find the best option.Best of luck to you and I look forward to following your journey!

When a lease expires but the tenant stays, they remain on the same terms as a month-to-month tenant.

@susan @Susan Little I agree about staying away from foreclosures as they can hide some nasty surprises from costly unexpected repairs to undisclosed liens.  

Have you asked them how long they want to stay?

I havent tried post cards yet, was trying to stay within a certain budget.

My friend's family is poor but I'm planning on helping him fix that with our business ;)We live in the Daytona Beach area in Florida which as many people know is where the NASCAR Daytona 500 is held along with Bike Week so the housing market is ridiculous here (in a good way)We're thinking since we are both going to stay with our parents well into our 20's we should make our first investment on a duplex so we'll have a great financial boost from 2 units funding us.I just want some opinions from experienced investors on how they feel about this plan.

Stay out of bonds in a rising rate environment, but get chunks out of mutual funds/equities for sure.I'd convert to a Roth or withdraw more during lower income years if I could.

I want to rent it out to my LLC, stay in the home, pay the rent and write off the expenses.