@Dave Ostrofski read your landlord tenant laws but decreasing rent proportionate to the unusable space could be supported by your local landlord tenant law, if you are saying it is a major loss of use. 

They refused to clean the carpets and went on and started replacing all carpets in approximately 700sq ft living space.

Houses that look very similar on paper (same neighborhood, style, square footage, year built, beds and baths) can have very different market values depending on things like interior light, flow, ceiling height, privacy, yard space, neighbors, curb appeal, master bedroom size, kitchen counter and cupboard space, parking options, driveway slope, proximity to noise or businesses, parks, schools, etc. - to name just a few things. 

I have a property with a detached garage that's partially converted that I want to convert to a living space.

Looking at buying this town for 680,000 gala  (or about $60,000)  it has 35 spaces to rent out.  

This property has a separate entrance to the downstairs unit and the space to add a kitchen.

I have a house in the Orlando market and if it's not already Disney/Universal themed out then I wouldn't call it "turnkey" because you are likely going to want to add that stuff to meet the revenue numbers you're projecting.

The thought is, we would buy the building through our LLC, and his construction company would rent out that space.

The biggest plus with the J&G community is the people: I instantly grew my network with fantastic people with great experience in this space.

@Adam SharpI would let them know that they hold a contract (called a lease agreement) that says they have the right to occupy that space until the specified date.