Tear-downs are a HUGE issue over here; every county suburb inside the 270 ring has been gutted by developers building spec tear-downs that they can advertise as being in those good school districts. Kirkwood and Brentwood, in particular, are nearly unrecognizable from as recently as 4 years ago. Both towns had a few blocks of large homes that were showpieces, including Old Kirkwood's Painted Ladies, with the rest of them built from 1920-1950 and rather small & unassuming. Brentwood, even had a large group of Lustron homes. The average price in Kirkwood had been around $325K for most homes, with Brentwood's less tony addresses going for about $250K. Kirkwood's home were about 1/3 brick and 2/3 wooden siding, but almost all of Brentwood's smaller homes had been beautifully crafted St. Louis brick (which, coincidentally, sells for $1400/pallet now. That was a little bonus for the construction companies who traded for it and hauled it away to use it to build house extensions in Ladue.)
Those smaller homes have all been destroyed and replaced by much larger "wooden farmhouse" spec houses with an average price of $825K. Driving DD to the rink over the course of last summer, I saw whole streets in Kirkwood go down at a rate of 1 house per week; people were being offered 30% more than the house was worth purely to get the land, and the house that went up to replace it was priced at 4X the cost of the one they took down. What drives me nuts about the giant houses is that front garages have been allowed on them, whereas the rule there had always previously been that the garage had to be placed in the rear. But you can't do that when you're counting on taking the walls right up to the minimum setback to make the house as large as possible. It's ruined those beautiful streets.