From Fredericksburg.com, we learn that a county in Virginia recently studied some of its urban planning decisions and their possible economic impacts. One of the topics studied was different building types -- houses, apartments, and townhouses -- and how much each would generate in tax revenue and costs in government services. The study concluded that "Each townhouse costs the county $1,368 -- roughly three times as much as a regular house and about $500 more than an apartment. Those figures compare the cost of county services such as schools and fire protection with tax revenue. Essentially, townhouses demand services similar to those required by regular houses, but their lower values mean less tax revenue." Full article here. (Photo of a townhouse in Fredericksburg, credit weichert.com.)
Update: Townhouse Center makes no representation about the accuracy of the above-mentioned study. See comments for counter-example from reader. Thanks, Dan.