Developers of multi-million dollar properties can use depreciation and various techniques to create six to seven figure losses on paper.

You never know what others will consider a good deal or the right deal for them.Learn great negotiation techniques.

So I always tell people to compare adding the ADU vs enlarging the existing home (for ADU’s inside building envelope.)

I have heard the BRRRR technique quite a bit... so I will be looking into that and will reach out if I have more questions.... which I know I good for. 

And you'll have new cracks in unexpected places, old cracks that will not close, but instead enlarge.

Sounds like a water leak issue.....bad liner, improper water sealing techniques, bad plumbing...all kinds of causes....How old are these units?

And yes, there is very specific techniques on how to do it.  

What things to look for, what techniques should I implement, what hints and signs to pay attention to?

There are a handful of techniques that get repeated.Bad reviews are hurtful. 

Put in a couple of comfy chairs for visitors too.Then Mom gets the next two levels to make a living room and bedroom and bath out of.Just do temporary modifications to floor one.And if you can see the ocean from it, maybe enlarge all of the ocean side windows and add large walkout balconies on floors two and three.Good Luck!