@Joshua S.Exterior - nope most won't care about anything but the roof and that would be minimalInterior - this is where you make the most difference, kitchen upgrades especially granite or quartz will be the most bang for your buck, followed by a hard surface flooring in your main living space (tile, high quality laminate, hardwood etc.) and bathroom upgrades starting with the master and working down from there.Additions - you aren't going to be doing a quality addition for $10-15k and if you do make sure it is done well or it can actually hurt your value

We plan on upgrading to a 4 unit property in a nicer neighborhood in the next couple years, so we may be looking at your new neighborhood!

Rents are much lower than market and we plan to raise them eventually by upgrading the units a bit.

After some upgrades and appreciation, it's probably $730k now.

In KC, the best bang for you buck are kitchen upgrades, adding a bathroom if possible, adding a bedroom if less than 3 bedroom house, and upgrading paint and flooring.

Are you using skip-tracing or something similar to upgrade the chances you can call the owner?

A house hack is meant to live in and upgrade as you go.

We under the concern over air quality as it affects us all, however we have no plans to upgrade the windows."

@Nicholas LambertI would speak to some electricians and get an idea of what it will cost to upgrade.

Unit 2  and 3's heating units either need to be fixed or upgraded.