Here is a list of the common apartment expense categories you will come across when analyzing deals:Maintenance and repairsContract servicesPayrollAdvertisingAdminTurn/make readyUtilitiesManagement feeTaxesInsuranceThere are also other losses, includingLoss-to-leaseVacancyConcessionsUnits (employee, model, etc.)Bad debt

Most physical items have standard to upgrading models. 

A virtual walkthrough would give you a model of a property that you could walk through at your own pace.

But to get that answer, Desmond and Wilmers would have to get their nice clean academic hands dirty and see why running these rentals is so difficult and unpleasant, takes so much time and effort, and carries with it as much risk as it does.I'm not saying there aren't plenty of out-and-out slumlords whose business model is very clearly to take advantage of poor people by any means necessary, legal or illegal.

@Richie Thomas this is a model some investors use and is quite common in commercial sales where they are referred to as an anchor tenant.  

Mine was mostly financial, and my brother’s was mostly expertise and work on the house.

I've design everything from complex spreadsheets, to website scrapers, integrate APIs from a wide variety of sources, real time notification systems, dashboards that leverage machine learning libraries to build data models.

My plan is to continue to emulate this model.

Now if that's your business model, then that's fine.

Essentially, the Push-matic breaker is an older model breaker which was installed until around the early '80s and, as the name implies, incorporates  a pushbutton style breaker switch.