Two developers behind One River North, the so-called “living structure” under construction in RiNo, now have their eyes set on an adjacent site.

Last week, the city received a concept plan proposing a 16-story apartment building at 3911-3963 Walnut St. near RTD’s 38th and Blake rail station.

The document lists the developer as Denver-based Wynne Yasmer Real Estate, which is developing the adjacent One River North apartment building across the alley at 3930 Blake St. with Uplands Real Estate Partners and The Max Collaborative, two firms formed by members of the founding families of Forest City Realty Trust.

Renderings for that 16-story building show a sort of haphazard gash on the structure’s northwest-facing facade filled with greenery.

Wynne Yasmer co-founder KC Yasmer said the second project would be a partnership between his firm and Uplands. He declined to comment further.

The 0.93-acre Walnut Street property is owned by developer Mike Mathieson of Forbes Partnership, who paid $3.5 million for it in 2015, records show. The site currently has industrial buildings on it. Mathieson declined to comment.

The plans for the building call for 359 units and about 12,000 square feet of ground-floor retail space. There would be 375 parking spaces underground and on the second floor.

It’s not clear if the second building would feature any structural or architectural flourishes to rival One Rival North. Concept plans are an early-stage proposal, and the document contains only basic drawings showing the scale of the proposed structure.

Davis Partnership Architects is listed as the architect on the plans for the latest project. The firm is the executive architect on One River North, but Chinese firm MAD Architects is the design architect for that building.

Wynne Yasmer, Uplands and The Max Collaborative are also building an apartment complex near the Anschutz Medical Campus in Aurora.