Maintenance estimates - townhouse vs. SF home

[Ben Kirchner]

In a townhome, with the exterior of the house covered by the HOA fees, do you typically estimate the maintenance costs lower than you would on a single family home? In my NOI estimations, I've always put 10% of the (Rent - Vacancy factor) to use as a maintenance reserve for the property. Are there recommended numbers to go by that differ depending on the type of property?

Thanks for the input.