about Baker Street Partners

Baker Street Partners is a neighborhood-focused real estate development firm proudly based in Manayunk/Roxborough, Philadelphia. We specialize in the acquisition and development of residential and multifamily properties, with a focus on adaptive reuse and carefully considered new construction. Every project is managed entirely in-house—from concept to completion—by a seasoned team committed to craftsmanship, integrity, and timeless design.

Founded by lifelong friends Steve Olszewski and Andy Mulson—who grew up together on Baker Street and still call the neighborhood home—BSP is deeply rooted in the community that shaped them. Their mission to reinvest in Northwest Philadelphia has grown into a collaborative, multigenerational effort.

Today, BSP’s leadership team includes Andy’s son, Andrew Mulson, and Steve’s brother, John Olszewski. Together, they bring fresh perspective and a shared commitment to BSP’s founding values, carrying forward a vision of development that honors the past while building toward a more vibrant future.

Guided by a deep respect for architectural heritage, we are dedicated to restoring and reimagining the historic fabric of Northwest Philadelphia. We take pride in being responsible, civic-minded developers who design with purpose—enhancing the character of the neighborhoods we live and work in, and creating lasting value for the broader community.