Basement Renovations: Expanding your Philadelphia Row Home Below
- Jul 7
- 5 min read
Table Of Contents
What Is a Basement Dig Out, Remodel, or Refinish?
If you're a Philadelphia homeowner sitting on a low-ceiling basement, a basement dig out or basement underpinning project might be the best way to add usable living space to your home.
A basement dig out, sometimes called basement underpinning, is the process of excavating beneath an existing home to increase basement ceiling height. Most older Philadelphia basements have ceiling heights between five and six feet, which makes them uncomfortable, unusable as living space, and difficult to finish in any meaningful way. A dig out lowers the floor so the space can function as real, livable square footage.
The process typically involves excavating soil beneath the existing foundation, underpinning the foundation in carefully sequenced phases, pouring new concrete footings and walls, installing drainage and waterproofing systems, and pouring a new basement slab. The result is a structurally reinforced basement with standard ceiling heights, ready to finish however you'd like.
Should I Renovate my Basement?
Deciding whether to take on a basement renovation comes down to a balance of lifestyle needs, property constraints, and financial investment. In a dense city like Philadelphia, expanding your home outward or upward isn’t always an option due to lot lines, zoning restrictions, or historic guidelines. If you love your current neighborhood but desperately need more space—whether for a growing family, a dedicated home office, a guest suite, or an entertainment hub—renovating the basement allows you to unlock substantial, usable square footage that you already own without the hassle and cost of moving.
However, because most historic Philly rowhomes were built with shallow, unfinished basements meant only for mechanicals, a true transformation often requires a structural dig out to achieve comfortable ceiling heights. This makes it a major investment compared to a standard cosmetic remodel. If your home already has decent headroom and a dry foundation, a straightforward refinish is a no-brainer. But if a dig out is required, you should weigh the project cost against the long-term value it adds to your daily life and your home’s eventual resale appeal. If you plan to stay in your home for years to come, turning a cramped, dark cellar into an airy, inviting living space is almost always worth it.
How Much Does a Basement Renovation Cost?
Most basement renovations typically fall somewhere in the $100,000-$250,000 range depending on the size of the basement, the amount of structural work required, and the level of finishes involved.
The biggest factor is usually complexity. Some basements only need basic excavation and underpinning, while others require extensive waterproofing, utility relocation, drainage systems, or difficult access conditions common in Philadelphia rowhome renovations.
Finishes also play a huge role in pricing. An unfinished basement will cost far less than a fully finished space with flooring, bathrooms, tile work, custom built-ins, or high-end fixtures. Even adding a single bathroom can noticeably increase the scope of work.
Because crews are excavating directly beneath an existing home, basement dig outs are highly specialized structural projects that require careful engineering, safety precautions, and sequencing throughout the process.
Do I Need to Move Out During a Basement Dig Out?
A lot of homeowners ask us whether they can realistically stay in the house during a basement dig out. The answer really depends on the scope of the project and how the basement is accessed. There are some projects where clients are able to remain in the home for a portion of construction, especially if crews can enter directly through the basement and avoid disrupting the main living space too heavily.
That said, we usually recommend moving out if possible. Excavation, underpinning, concrete work, and waterproofing can make the home extremely noisy, dusty, and difficult to live in for stretches of the project, particularly in tighter Philadelphia rowhomes.
How Long Does a Basement Dig Out Take?
Most basement dig outs take several months from initial planning to final completion. The actual construction timeline usually depends on the size of the basement, the amount of underpinning required, site access, and how extensive the finishes are afterward.
The structural portion of the project tends to move slower than a typical renovation because excavation and underpinning have to be completed carefully in phases to safely support the home throughout construction. Permitting, inspections, waterproofing, and utility work can also add time depending on the complexity of the project.
In tighter Philadelphia rowhomes, limited access and neighboring properties can sometimes slow things down even more.
What Permits Are Required for Basement Underpinning in Philadelphia?
Most basement dig outs require several approvals through Philadelphia’s Department of Licenses & Inspections (L&I), starting with detailed architectural and structural engineering plans. If your rowhome is located within a designated historic district, these plans must first be reviewed and approved by the Philadelphia Historical Commission to ensure the excavation won't jeopardize neighboring historic structures. This initial review is a crucial prerequisite and can add several weeks or months to your pre-construction timeline.
Once historic clearances are secured, your plans officially enter the standard city pipeline. The project will undergo building, structural, and sometimes zoning reviews through L&I. Since most finished basements include livable space and extra bathrooms, separate trade permits for plumbing, electrical, and HVAC work will also be pulled concurrently to cover the full scope of the project.
After L&I issues the permits, construction can begin—but the city’s involvement continues through phased inspections. Because underpinning is highly structural, city inspectors must review and sign off on key milestones like excavation, concrete footings, waterproofing, and framing before the crew can move on to the next stage of the build.
Your Next Steps
The first step is figuring out whether the investment, timeline, and added square footage make sense for your home and long-term plans. It's also worth thinking through how you want to use the space and what level of finish you're after.
From there, the next step is scheduling a complementary consultation with our team so we can evaluate your basement and walk you through what is realistically possible for your home. After the initial call, we will meet with you at the property to review the existing conditions, discuss structural considerations, and get a preliminary budget. From there our architectural designer will help design the space to your desire, we will pull all permits, and get to work building your new basement space!
If you’re exploring a basement remodel or basement renovation, click the link below to get in touch with our team.
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