What We've Done
Apartment & Office Rentals
GM Holdings, LLC is a property management company dedicated to commercial and residential realty in Fishtown, Harrowgate, Kensington, Northern Liberties & Port Richmond, Philadelphia. Click here to see all available properties!
Why Work With Stronghold?

We Invest In The Community
We understand the importance of stabilizing local neighborhoods that are negatively affected by neglected properties.

We Stand Out
We believe in high-quality developing with unique layouts and individual touches. We want to help make your vision come true, however big or small.

We Are Affordable
We understand the value of a dollar. That's why we over complex development and construction at a modest price.

We Care About Our Clients
We are happy to collaborate with investors and the community to ensure that everyone is satisfied.
Features
Philadelphia Magazine

New Construction Factory-Style Loft Apartments Now Available in Harrowgate
The loft-apartment aesthetic remains popular with a large swath of city-lovers. These fans of industrial chic have flocked to the converted factories and warehouses found in neighborhoods all over the city, and builders have responded by scooping up old industrial buildings further and further afield from the neighborhoods like Callowhill and Northern Liberties where such buildings abound.
Stronghold Development, the construction arm of Manosis’ real estate enterprise, installed the framework for a dropped tile ceiling in each kitchen but omitted the ceiling tile, except where lights were placed. “We think it’s a cool aesthetic,” says Anthony Castaneda of Keller Williams Philadelphia, who is part of the team that markets this development.
Philadelphia Magazine

Apartment Week: J Street Lofts
As of now, the wave of reinvestment, redevelopment and revitalization that’s transformed large swaths of North and South Philadelphia has yet to leap over the huge freight railroad embankment that crosses eastern North Philadelphia on its way to the massive former Reading Railroad pier complex in Port Richmond.
Kensington developer George Manosis has just placed a huge bet that it will, and soon. In fact, you could call his J Street Lofts complex, a mere block from the Tioga El stop in Harrowgate, the bleeding edge of that wave.
PhilaRising

Old School Getting Converted in Harrowgate
Many people think that development pressure from East Kensington may jump right to Harrowgate and skip the area between Somerset and Allegheny because of that neighborhood’s opioid epidemic. The belief is that Harrowgate will see large-scale development before northeast Kensington, even though it is farther away geographically from Center City and gentrified neighborhoods such as Fishtown.