On higher end, luxury rentals, it could be a nice feature though those types of tenants probably won't have any problem just paying it themselves.

Rick, appreciation of an apartment complex comes from either an increase in NOI or reduction of cap rate or both.

@Brandon Turner do you know if BP still has this feature available and if so how do I locate them.

Corey Lee what is your target cap rate and are you looking to have it managed by a PM?

Depending on area and specific property, you may also have some utility costs and/or landscaping.Trash service - some areas included in taxes, others usually tenant pays, but if landlord typically pays, add that in.Maintenance and cap ex, when you have a specific property you can fine-tune those numbers.  

2. effect my Fannie and Freddy cap of 4 properties?

For office I would be wanting a 9 to 10 cap or higher at this point in the cycle. 7 to 8's for that product is overpriced at this time in my view unless rents are at about half of current market.

Paul, thank you I have a realtor in the area that could give me the cap rates, etc.

I've taken some courses in analyzing investment properties, produced APOD's, noticed the drawbacks in how the typical Cap Rate is calculated, and dug deeper to find four-square and the mortgage constant. 

Cap rates are typically higher and you have multiple tenants to pay rent.