Commercial real estate in Brooklyn remains strong, according to the latest report from commercial realty group TerraCRG. In the first half of the year, there were 563 sales worth more than $1.23 billion. That’s an increase of 50 percent in dollar volume over the same period last year, according to TerraCRG. Here’s why: Prices of development sites have increased. Development site transactions accounted for more than 15 percent of the total dollar volume. Not surprisingly, Downtown and Park Slope led in highest dollar volume of total sales, with Williamsburg and Greenpoint closely following. But surprisingly, the combined areas of Bed Stuy, Bushwick, and Crown Heights had the most amount of trades. Perhaps landlords see potential in those areas?