1. Windows. Glass is one of the most delicate substances that we use in a home. Although they do allow for the potentially beautiful views that so many people seek out, they can also present a danger if high winds and trees or other debris join together. The same thing that allows us to see out and lets light in may become a dangerous shattered projectile if a storm is severe enough. Storm windows are made especially to try and combat this possibility, and are a good addition to any rental property you may own. Even windows that are more than a single pane thick are a good idea, and this will also help keep heat and cool air in during the extremes of the temperatures of the year.
2. Drains. Drainage is a very important feature to have near your rental property. While most of the drains that will be used are installed by the town, you can normally request an added drainage system from your township. Even if you have a good and solid drainage area near the building, depending upon how the property is set up, there may be areas that are more likely to flood in the event of heavy rain. This is true of any ground floor or underground apartments. If there are steps that lead lower than the lawn, you may want to try and install a drain at the bottom of these stairs to lessen the possibility of severe water damage to the apartment.
These are only a couple of ideas of what to watch for in a building that you may be renting out, but they can save you quite a bit of money and a lot of headaches along the way. Hopefully you will never have something severe happen to your buildings, but just in case, these are things that may be able to help you along the way.