I also have a mortgage on this property paying $683 a month.Now I'm deciding should I continue waiting for a possible tenant or should I just sell the property.

Becoming a LandlordYour house appreciating at 5% annually = $25K/year.Your parents' larger house = $30K/year.Financing the PlanTake out a mortgage on your house to buy your parents' house.If their mortgage rate is lower than today’s rates (6.75%), keep their mortgage and assume it.Why It WorksYour tenants pay the mortgage—not you.Each monthly payment includes ~$300 toward the principal.

If they pass all of the checks and have the proper income then they have a shot at moving in.

that we’ve learned in our 24 years, managing almost 700 doors across the Metro Detroit area, including almost 100 S8 leases:Class A Properties:Cashflow vs Appreciation: Typically, 3-5 years for positive cashflow, but you get highest relative rent & value appreciation.Vacancy Est: Historically 10%, 5% the more recent norm.Tenant Pool: Majority will have FICO scores of 680+ (roughly 5% probability of default), zero evictions in last 7 years.Class B Properties:Cashflow vs Appreciation: Typically, decent amount of relative rent & value appreciation.Vacancy Est: Historically 10%, 5% should be applied only if proper research done to support.Tenant Pool: Majority will have FICO scores of 620-680 (around 10% probability of default), some blemishes, but should have no evictions in last 5 yearsClass C Properties:Cashflow vs Appreciation: Typically, high cashflow and at the lower end of relative rent & value appreciation.

Yes one had a mortgage, but I was still happier and better off.

Are you saying I need to take a second mortgage on the rental? 

This will get you the name on the dog on record designating that specific animal as their ESA.Good idea -- AND ask for additional rent/deposit, unless there is some legislation forbidding it for a properly registered service animal.My humble opinion, all this "emotional support" stuff is simply BS so they can take their precious animals everywhere they go and not have pay extra.

@Charles Evans, definitely keep all paperwork associated with your tenant (lease, receipts, etc).For expenses that are not split per unit but are for the entire structure (utilities if not separately metered, mortgage interest, etc), keep a record of those payments so your tax pro can deduct a percentage of them for the unit you're renting.

This is making my mortgage payment go from $2,293 to $3,308 per month. 

@Jonathan Blanco, I'm and investor and a licensed mortgage broker so I've been on both sides of this conversation.I would look for a lender that (1) listens to you and understands your strategy and needs (hint: it's not always money), (2) has experience working with clients executing your strategy and brings more to the table than just cash - be it advice, relationships, deal-team partners, etc., (3) gives you viable options and explains the pros and cons of each option and (4) you enjoy interacting with - this should be a relationship, not a transaction.Once you find a few lenders like this (and you should have relationships with more than one), then you can start comparing rates and fees.