The Brooklyn luxury market saw a significant boost from townhouses between Sept. 30 and Oct. 6, with 15 units going into contract for a total of $57 million, nearly doubling the previous year’s volume. Twelve of the deals were townhouses, with a median asking price of $4 million. The top contract was for a Cobble Hill townhouse at 321 Clinton Street, priced at $11.3 million. Another notable contract was a historic carriage house at 195 Waverly Avenue in Clinton Hill, listed at $4.8 million. Both properties sold quickly, spending less than a month on the market.