It’s big. It’s blue. It basically anchors the western edge of Center City’s high-rise core without trying too hard to be the flashiest kid on the block. If you’ve ever walked down JFK Boulevard or stuck your head out a window in Logan Square, you’ve seen it. 1835 Market Street Philadelphia isn't just another office box; it’s a 42-story slab of glass and concrete that tells the story of how Philly transitioned from a manufacturing hub to a white-collar powerhouse.
People call it the Eleven Penn Center building sometimes. Or they just know it as the place with that massive, slightly reflective facade that catches the sunset perfectly. It’s got roughly 800,000 square feet of space. Think about that. That is a massive amount of floor area for people to drink lukewarm coffee and stare at spreadsheets. But honestly, it’s the location that makes it work. You’re steps from Suburban Station. You’re right there in the mix of the Market Street West corridor.
The Weird History of the "Penn Center" Dream
To understand why this building exists, you have to look at the 1950s and 60s. Philadelphia was obsessed with the "Penn Center" plan. The idea was to tear down the old "Chinese Wall"—that elevated stone railroad viaduct that split the city in half—and build a shiny, modern office district.
1835 Market Street came a bit later, finishing up around 1986. It was designed by Kling Lindquist. If you know Philly architecture, you know Kling. They did everything. They were the masters of that late-modernist, slightly brutalist but mostly "corporate cool" look. When it opened, it was a signal that the city’s business district was shifting west, away from the old-school banks on Broad Street and toward the commuter-friendly transit hubs.
It’s funny because, at the time, people weren't sure if the city needed another massive tower. We were just hitting that era where the "Gentleman’s Agreement" (the unwritten rule that no building could be taller than William Penn’s hat on City Hall) was about to be shattered by One Liberty Place. 1835 Market was part of that final wave of buildings that respected the skyline's traditional scale while preparing for the vertical explosion of the late 80s.
Inside the Glass: What’s Actually Happening at 1835 Market?
Walk into the lobby. It’s got that high-ceiling, polished-stone vibe that screams "I have an appointment with a lawyer." It’s upscale but not intimidating. Nightingale Properties bought the place a few years back, and they’ve poured money into making it feel less like a 1980s time capsule and more like a modern workplace.
The tenant mix is a classic Philadelphia cocktail. You’ve got law firms like Hogan Lovells. You’ve got tech-adjacent companies and professional services. It’s the kind of building where the elevator chatter ranges from high-stakes litigation to where to get the best lunch in the Comcast Technology Center food hall across the street.
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The Transit Perk
Let’s talk about the commute. If you work at 1835 Market Street Philadelphia, you’ve basically won the logistics lottery.
- Suburban Station is literally right there.
- The Market-Frankford Line is a block away.
- You can hit the Schuylkill Expressway in five minutes if the traffic gods are smiling on you (which they never are).
Being "transit-oriented" isn't just a buzzword here. It's the reason the building stays leased while other older towers struggle. Employees actually like being able to roll off a Regional Rail train and be at their desk in three minutes without getting rained on.
Why the Design Actually Works
Some people think these 80s towers are boring. I disagree. There’s a certain ruggedness to the way 1835 Market is built. The floor plates are large—around 20,000 square feet. That’s huge. It allows for "open office" concepts that smaller, historic buildings in Old City just can't handle.
The views? Unreal. If you’re on the 30th floor looking west, you see the curve of the Schuylkill River and the sprawl of West Philly. Look east, and you’re staring at the clock tower of City Hall. It’s a perspective that reminds you how dense and layered this city really is.
The building also underwent major renovations to its HVAC and mechanical systems. Nobody cares about chillers until they stop working in August. By modernizing the guts of the building, the management kept it competitive with the brand-new glass towers popping up nearby. It’s about being "Class A" without the "Class A+" price tag.
The Post-Pandemic Reality
Look, we have to be real. The office market in Philly—and everywhere else—took a gut punch over the last few years. Remote work changed the math. But 1835 Market Street has stayed surprisingly resilient. Why? Because it isn't just a cubicle farm. It’s positioned as a "destination" office.
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There’s a fitness center. There’s upgraded conferencing space. There’s a bike room for the people riding in from Fairmount or South Philly. It’s trying to solve the "why should I leave my couch?" problem by providing amenities you can't get at home.
The vacancy rates in Center City have fluctuated, but the "flight to quality" is a real thing. Companies are leaving crappy, older buildings and moving into spots like 1835 Market because they want their employees to feel like they’re in a premium environment. It’s a survival-of-the-fittest situation for commercial real estate right now.
Surprising Details Most People Miss
Most people don't notice the plaza area or the way the building interacts with the street level. It’s not just a wall of glass. There’s a rhythm to the way it sits on the corner of 19th and Market.
- The building has an Energy Star rating that’s actually pretty impressive for its age.
- The window-to-wall ratio was designed to maximize natural light before "wellness architecture" was even a thing.
- It survived the 1990s real estate crash, the 2008 recession, and the 2020 lockdowns. It’s a tank.
It’s also worth mentioning the retail. Having immediate access to a Wawa (obviously) and the various shops along Market Street makes a difference. You don't have to go on a trek just to find a decent sandwich or a phone charger.
The Future of the Market Street West Corridor
Where does 1835 Market Street Philadelphia go from here? The city is leaning hard into life sciences and tech. While 1835 is primarily traditional office space, the entire neighborhood is shifting. With the massive investment in University City just across the bridge, this building acts as a bridge between the old "CBD" (Central Business District) and the new "Innovation District."
There’s talk about more residential conversions in Center City, but it’s unlikely 1835 will ever go that route. It’s too well-suited for its current purpose. It’s the "reliable veteran" of the skyline. It’s the building that does the work so the newer towers can win the design awards.
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Actionable Insights for Tenants and Visitors
If you're looking at space here or just visiting for a meeting, keep these things in mind:
For Businesses: Check the sub-lease market. Because of the large floor plates, sometimes smaller firms can snag a "plug-and-play" suite that was formerly part of a much larger corporate footprint. You get the 1835 Market prestige without needing to furnish 20,000 square feet.
For Commuters: Use the concourse. You can stay underground for a significant portion of your walk from the train if the weather is trash. Learn the "secret" exits that pop you out closer to 19th Street.
For Architecture Nerds: Stand at the corner of 19th and JFK and look up at the way the light hits the blue tint of the glass. It’s one of the few buildings in the city that changes color significantly depending on the cloud cover.
For Job Seekers: Keep an eye on the tenant roster. The firms in this building are typically stable, high-earning professional services groups. If you want a job in the heart of the "real" Philly business world, this is where you start your search.
Ultimately, 1835 Market Street is a survivor. It represents a specific moment in Philadelphia's growth—a moment when we stopped looking backward at our colonial history and started looking toward a high-rise, high-density future. It’s not just glass and steel; it’s the physical manifestation of the city’s hustle. Next time you're stuck in traffic on Market, look up. It's a lot more interesting than it gets credit for.
Next Steps for Engagement
- Verify current availability: If you are a business owner, contact the leasing agents at JLL or the current property management to see current floor-plan options.
- Explore the neighborhood: Walk the three-block radius between 17th and 20th Streets to see how the "West Market" vibe differs from the more tourist-heavy parts of the city.
- Audit your commute: If you’re considering a job here, do a "test run" on SEPTA's Regional Rail to Suburban Station to see just how close the walk really is.