Issues 1) even garage conversion ADUs in single family zoned areas typically cost more to build than the value that they add.  

., but there’s some good news for renters: local rents have dropped to a 3-year low, with decreases of up to $200.

Obviously need to check zoning and set up costs etc. 

Everybody thinks they can paint because they can - you get a brush or a roller, a can of paint at Lowe's and away you go.

Those holding cost will certainly add up over time and kill any cash flow.

Both sides also need to factor in opportunity cost.

However, the success of your project will depend on factors like location, renovation costs, and market timing.Many investors have found great success by focusing on high-demand neighborhoods with strong buyer interest.

These low quality tenants are more difficult to get rid of.

I do not think it would cost too much to tone it down howeverI got a $10k quote (minus fees) from an interior decorator recently to redesign.

Oil heating costs are outrageous and you also have to deal with leaking tanks which can be a nightmare.