A small building is planned for the corner of 5th Avenue and St. Johns Place, replacing a vacant lot and bringing some rare new construction to the North Slope retail drag. A crew’s been doing prep work on the site over the past month or so, and DOB filings say a five-story, four-unit structure’s in the offing. The lot’s been vacant as long as we can recall; anyone know if there was ever a building here? GMAP P*Shark DOB