Townhouse madness

I walked up to Val's Cafe on Phinney Ridge for breakfast this morning. (I actually first attempted to graze at Mae's, but they seemed to be having a temporary service malfunction, so I gave up.) On the walk back, I noticed that there was new construction going on along 45th between Phinney Ave and Fremont, apparently townhouses in both cases. I got off the beaten track by walking along Evanston below 45th, and I thereby discovered that several new townhouses have gone up on that street too, with yet another lot cleared on 43rd for new construction of some kind. In fact, there seems to be an explosion of townhouse construction in the area. The old trolley substation around the corner from us on Albion has been torn down, and Albion has become townhouse row.

In the boom in the late '90s, a lot of condos went up in Seattle. There are still some condos going up (including a major project on the corner of 45th and Stone Way), but it seems like townhouses have become the new trend. And I mostly approve, although there are as usual too many mediocre designs (some of those color schemes are just going to scream the Naughties eventually). But I like the scale of townhouses better as a neighborhood sidestreet thing; condos seem to go better on arterials.

I guess I'm curious why townhouses became so popular all of a sudden. Was there some kind of zoning decision that was favorable, or a townhouse expo that convinced everybody that they were a good idea? Were they the hot thing in NYC of San Francisco five years ago? What happened? Are they cheaper than condos?