I would buy more efficient new boilers and then solve for A/C if needed...

When someone buys a property using SubTo, does that make then legally responsible for the loan?

I am on fire to get going, and to stay on track with my plan I will have to buy minimum 1 property this year.  

It assumes the property is Class A - which not a lot of investors are acquiring these days.Here's some copy & paste info about property classes:_____________________________________________________________________________Recommend you first figure out the property Class you want to invest in, THEN figure out the corresponding location to invest in.Property Class will typically dictate the Class of tenant you get, which greatly IMPACTS rental income stability and property maintenance/damage by tenants.If you apply Class A assumptions to a Class B or C purchase, your expectations won’t be met and it may be a financial disaster.If you buy/renovate a property in Class D area to Class A standards, what quality of tenant will you get?

So you can buy a four flat, live in one unit and rent the other three, but you have to live in one unit on the site. 

Quote from @Allison Cutlip: Hi all, My boyfriend and I are buying our first home that is a duplex, planning to live in one unit and rent the other side.

(The power company in MN will offer you a chance to buy the warranty after the furnace/ac is broken and come back the next day to fix for free.)

Remember, if you sell it, you'll have capital gains that you will have to pay since you are buying the other property before you sell you're old house.

I was living abroad buying/selling real estate mostly land, and some land with structures.

@Hiyun Park only experienced investors can DIY everything in Class C Midwest areas like Detroit, Cleveland, St Louis, etc.Hopefully the info below will help you:-----------------------------------------------------------------------------------------Recommend you first figure out the property Class you want to invest in, THEN figure out the corresponding location to invest in.Property Class will typically dictate the Class of tenant you get, which greatly IMPACTS rental income stability and property maintenance/damage by tenants.If you apply Class A assumptions to a Class B or C purchase, your expectations won’t be met and it may be a financial disaster.If you buy/renovate a property in Class D area to Class A standards, what quality of tenant will you get?