Typically you see people reserve 8.3% vacancy, 10-20% repairs/maintenance/cap ex; 8-10% property management in addition to things like insurance, taxes, any landlord paid utilities, lawn maintenance, etc.

http://www.wcequitygroup.com/properties/4577620045Cost Analysis Performed as Rental PropertyIn:Rent - $11,100.00Out:(Annual) Estimated Taxes - $500.00(Annual) Estimated Insurance - $850.00(Annual) Property Management (Optional) - $888.00(Annual) Estimated Utilities/Lawn/Misc -$555.00Total Costs - $2,793.00Net:$8,307.00Earn:Total yearly net equates to -$8,307.00Total monthly gross equates to - $925.00

Takoma Park in particular with their low threshold of 2 units creates these artificial ghettos where all their multifamilies are located.

As I think about creative ways to obtain my first property, I can't help but think a little outside the box.I own a lawn maintenance business and while we mainly deal with residential (better money), the company can handle small to mid sized commercial properties.

I'm retired from the Navy and own my own lawn care and landscaping company,  interested in learning all aspects of flipping homes .

No external lawn maintenance.

If you are doing the lawn mowing yourself every two weeks, then you'll want it to be close.  

For example, if the management company is only contractually responsible for grounds keeping like lawn mowing and landscaping he/she may have a way out of obligation by law. 

Thank you ned carey for your advice, the couple owns the property they always come by to do the lawn and I made the offer year ago and they refused it but last week they said they want to get rid of it.

BTW - I am also interested in lawn service for the Northside (Wicker Park and environs).