The basement isn’t even built yet, but the folks developing the large site at 309-321 2nd Street have already picked a name and marketing campaign. Here’s what we know: The residential development will be called The Heritage at Park Slope and consist of 21 one- and two-bedroom units. The Karl Fischer-designed building will be four stories high for a total of 24,000 square feet; no renderings yet on the architect’s web site. What’s interesting is that it appears that the developers are actually the same people who owned the old tile company that used to inhabit the two-story warehouse structure that used to be here. GMAP P*Shark DOB