Tall isn&#x27;t the answer, dense is. The proper question is &quot;when you give up 1km² of farmland, how many beds and offices do you get in return?&quot; (or a little more sophisticated). Tall doesn&#x27;t actually correlate very well with dense, because it tends to be a small part of the ground.<p>IIRC Bldgblog wrote that the US has about four ground-level parking spots per car. (Can&#x27;t find the posting again now, but <a href="http:&#x2F;&#x2F;www.bldgblog.com&#x2F;2007&#x2F;10&#x2F;greater-los-angeles&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www.bldgblog.com&#x2F;2007&#x2F;10&#x2F;greater-los-angeles&#x2F;</a> and everything it links to is a fine place to start.) If you build some highrises, plus big flat malls and office parks, plus four parking spots for each car owner that&#x27;s expected to move in,  plus enough streets, then the highrises don&#x27;t matter. You could build them half or twice as high and it wouldn&#x27;t make a real difference to the density.