360-unit residential new construction, zoned CMX3.


A 25-story, 360-unit residential tower is under construction at 300-46 N Christopher Columbus Boulevard in Old City, cleared to build in late 2021 on a 69,000-square-foot lot. The project includes ground-floor shell commercial spaces that will require separate fit-out work before occupancy, plus a rooftop deck and an accessory parking garage. At that height and density, it's easily one of the largest residential projects to gain traction along this stretch of the waterfront in years, layering significant new housing onto a corridor that has historically struggled to find its footing between the Delaware and I-95.
The site is zoned CMX3, which allows the project to proceed by right without special approvals—a straightforward path for a developer willing to build at scale on a property assembled by 300 Columbus LLC, which acquired the parcel in 2020. The tower's footprint and massing reflect the zoning's generous dimensional standards, making it a relatively clean play for a developer betting on long-term demand in a neighborhood that has seen fits and starts of investment over the past two decades.
This project doesn't exist in isolation. Within a half-mile radius, roughly 411 units are in the pipeline or recently delivered, including a 97-unit building at 500 N Christopher Columbus Boulevard and an 85-unit project at 230-36 Vine Street. The clustering suggests a modest but real shift in how developers are sizing up Old City's edges, particularly along Columbus Boulevard where older industrial parcels and surface lots have sat underutilized for years. The question is whether this wave of new housing will finally tip the balance toward more consistent street-level activation and commercial viability.
For nearby landowners sitting on surface parking or aging single-story warehouse shells, this tower serves as both proof of concept and pricing benchmark. CMX3 zoning extends across several adjacent blocks, and the success—or struggle—of a 360-unit project will inevitably inform the calculus for anyone considering similar moves along the waterfront. The neighborhood's trajectory now hinges on whether this scale of residential density can sustain the retail and street life that has eluded the area for decades.
📄 View the project's plan drawings (PDF)As this density arrives, InvestPHL is tracking 48 under-built parcels within a half-mile that a developer could still acquire and build — each carrying a builder's max bid. Addresses and figures are members-only.
Unlock the 48 nearby opportunities →Major (8+ unit) new-construction projects filed within a half-mile since 2022 — the density gathering around this site.