Multiply that over multiple properties and multiple years and that is the power of tax deferred growth.I would say the biggest snare is buying wrong with insufficient cash flow or over leveraging so that in down turns with rent rate deterioration you have to sell instead of being able to ride out the cycle.  

The gross rent multipliers are phenomenal and make out well for cash flow.

At this point, the property exhibits completed updates, increased revenues, and appreciation.So, the best use of investor capital is to sell the property so that they can seek their next investment project.Once the sale is complete, investors get your original capital back, plus a percentage of the profits.While slow & steady cash flow can be nice, selling the property allows investors to multiply their equity faster over time

In Louisville we have a metro ordinance that says the tenants voucher is to be counted as income and you must use the tenants monthly contribution to their rent, and multiply that by 3.

Now, to determine your depreciation basis, multiply your purchase price by 75%. to get $23,625 as the depreciation basis for the dwelling structure. 

You then apportion your other building expenses and report those on the Schedule E as well.Here are the expenses you'll want to consider:Mortgage InterestProperty TaxInsuranceWater/Gas/Electric/Sewer/Garbage Removal/Lawn Maintenance/Pool Maintenance (presuming your tenant is allowed to use the lawn and pool)Repairs to the property as a whole (ie, roof, plumbing, electrical repairs)Repairs specifically to the space you are rentingDepreciationYou then measure the room you've rented and compare it to the livable square footage of the house.So let's say you're renting a 300 square foot space, your bedroom is 500 square feet and you share the kitchen, bathroom and living areas and those common areas add up to 1000 square feet.So your rented space is 300 + (1000/2) for an effective square footage of 800 square feet rented.You then take the above mentioned expenses and multiply each one by (800/1800) and you claim that amount of expense.The only exception is repairs specifically to the rented area.  

The value they calculate is the county assessed value, which I found on the Allegheny County website, multiplied by 1.15.  

Multiply that process by all the properties we're working on at once, and it's whole day's work for numerous teams. 

@Sergio Rodriguez, one way to quickly check the trend is to take the trailing 12 and compare the T12 numbers to the T3 (last three months, multiplied by 4) to the T1 (latest month, multiplied by 12).

If your jurisdiction only allows you to use your rent multiplier on only the tenant portion of rent, then change your criteria to a flat amount instead of using a multiplier.