This 3rd unit is now an additional person who's going to ad to the noise, laundry & parking disputes that are already prevalent in these types of properties when there are 2 tenants.

So he collects less rent for the insurance office, but his expenses are correspondingly lower.Oh, be ready for residential tenant complaints upstairs when you have restaurants or delis downstairs, particularly odors and noise, especially if they open late.

Is it common that the noise cause a problem for the bottom unit?

Once you find a formula you'd like to pursue eliminate noise and focus getting educated on that one formula.Happy hunting!

Just have to find a way to grind through it.

Filter the noise and pull the trigger.  

All three matched the same price, but J&J offered to remove another tree that would be trouble in the future, and grind down a few existing stumps in my front yard.

Obviously this is a selfish request but I'd love to attend more webinars and can imagine that other newbies like me are still grinding at their day job while trying to learn more during any available free time.

If it is partially occupied you'll have a narrower window of acceptable time to make construction noise.  

As Larry said ambition and motivation account for very little without grinding out long hours of hard work, at least to start.Almost all failure, at least in the States, can be traced to unwillingness to work hard on your well-defined goals.