346-unit residential new construction, zoned CMX3.


A 346-unit apartment building is under way at 1225 Constitution Avenue in the Navy Yard, rising seven stories over a 1.5-acre site with ground-floor commercial shell space and a two-story parking podium. The project sits on CMX3-zoned land, a designation that allows this scale by right, and the design stacks five residential floors of Type IIIA construction atop the Type IA podium base. Originally cleared to build in late 2021 with 265 units, the plan has evolved through three amendments—adding two one-bedroom units on the second floor in place of a pool lounge, swapping out a theater for a warm shell marked as future amenity space, and shuffling egress routes on the pool deck.
1200 Normandy LLC holds the property, having acquired the site in 2023 after construction had already begun. The developer is delivering a fairly standard amenity package—pool deck, music studio, mail room—tailored to the young professional and defense-contractor workforce that has driven Navy Yard absorption over the past decade. The decision to leave commercial space as warm shell rather than pre-lease suggests caution about retail fundamentals in an area still building out its daytime population.
This building continues the Navy Yard's shift from office-led development to a more mixed live-work environment, though the absence of comparable residential projects within a half mile underscores how much of the district remains in flux. Constitution Avenue itself has seen uneven momentum, with large tracts still awaiting their next use as the broader campus inches toward build-out. The mix of parking podium and commercial flex space reflects the Navy Yard's car-dependent reality, even as transit advocates hope the area will one day support denser, less auto-oriented product.
What this project signals most clearly is that mid-rise, amenity-heavy rental remains the safe play for developers willing to bet on the Navy Yard's continued maturation. The amendment history—tweaking unit counts, relocating amenities, holding commercial space undefined—suggests a project shaped as much by market testing as by initial vision. As the building moves toward delivery, it will test whether the Navy Yard can absorb another 346 units without meaningful rent pressure, and whether Constitution Avenue can knit itself into a coherent streetscape or remain a patchwork of isolated complexes.
📄 View the project's plan drawings (PDF)As this density arrives, InvestPHL is tracking 3 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.
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