Another very similar house is under construction around the corner on Hamilton Place. The estate at the SW corner of Summit & Hamilton was subdivided. That large estate, along with the adjacent house on the corner of Passaic Street, had been held for DECADES by investors hoping for zoning changes to build something more.
Now that threat is completely eliminated by the subdivision of the larger estate.
In 2005, I wrote new zoning code for Summit Ave and vicinity. The R1 zone definition (75 x 100, 7500 square feet) was eliminated, and replaced with R100, R75, and R60. This site is in R75, which still means 75 x 100, but with 10,000 square feet lot size. The new house around the corner went from R1A (50 x 100, 5000 square feet) to R75 as well. Most of the remaining R1A zone was renamed R50, and it means the same thing.