Before You Demo Everything: Why Strategic Demolition Matters in Philadelphia Renovations

Written By liza arveladze

When renovating an older Philadelphia home, demolition can feel like the obvious first step: remove everything, expose the structure, and start fresh.

But before taking a historic rowhome or older house down to the studs, it is important to understand how Philadelphia treats existing buildings and existing conditions.

An existing condition that can legally remain in place may not necessarily be required to meet every provision that would apply if that same element were constructed new today. Once portions of a building are removed, relocated, altered, or reconstructed, however, the work may become subject to current code requirements.

That is why demolition should be part of the planning and permitting process, not simply the first step in construction.

What Does “Grandfathered” Actually Mean?

“Grandfathered” is a common construction term, but Philadelphia's codes use more specific concepts.

Philadelphia's Administrative Code states that, unless otherwise required by the technical codes, certain systems and equipment that were lawfully in existence when the applicable codes were adopted are not automatically required to be removed, altered, or abandoned. The Philadelphia Existing Building Code also specifically governs repairs, alterations, changes of occupancy, additions, and relocation of existing buildings.

In zoning, Philadelphia similarly recognizes nonconformities. A nonconformity is generally a use, building, lot, parking area, sign, or site improvement that does not comply with today's Zoning Code because it predates the applicable zoning requirement or was legally established before the requirement changed.

This does not mean that every old condition is legal simply because it already exists. An existing condition that was constructed illegally or without required approvals does not automatically become legal because of its age.

Why Demolition Can Change the Code Conversation

Philadelphia's codes distinguish between an existing building and the new work performed as part of an alteration.

Under Philadelphia Administrative Code A-102.8, additions, alterations, and repairs generally must comply with the requirements applicable to new construction, although applicants may elect to use applicable provisions of the Philadelphia Existing Building Code.

The code also specifically allows certain alterations to building systems to comply with requirements for new systems without requiring every untouched portion of the existing system to be brought into full compliance.

That distinction is important.

If an existing component can legally remain and is outside the renovation scope, leaving it undisturbed may be treated differently than removing it and constructing a replacement.

This is one reason the demolition plan should be developed alongside the proposed renovation plan rather than independently.

Interior Demolition Is Still Regulated Work

Removing an interior does not automatically mean that the work is exempt from permitting.

Philadelphia requires a Building Permit for projects that change the interior or exterior of an existing structure or partially or fully demolish a structure. L&I also provides a specific permit path for interior non-load-bearing demolition.

The City's Interior Non-Load Bearing Demolition permit category can include removal of:

  • Wall, floor, and ceiling finishes

  • Non-bearing partitions

  • Casework

  • Cabinets

  • Other nonstructural interior elements

This permit type is for demolition only. New construction and new finishes are not authorized under the interior demolition permit itself.

For qualifying projects involving only interior non-load-bearing walls and ceilings, Philadelphia also provides an EZ Permit process that does not require construction plans, subject to the City's conditions and limitations.

Partial Demolition vs. Complete Demolition

The amount of a building being removed also matters.

Philadelphia states that when a project removes more than two-thirds of the existing structural framing and alters an exterior wall, the project is considered complete demolition.

If only part of the building is being demolished, the work may instead qualify as an alteration and be reviewed through a Building Permit application.

This distinction can affect the permit path for a major Philadelphia renovation.

Existing Zoning Conditions Matter Too

Building code is only part of the analysis. Existing Philadelphia homes may also contain legally established zoning conditions that would not necessarily be permitted if proposed as new construction today.

Philadelphia's Zoning Code recognizes legally established nonconformities and provides rules governing their continuation, modification, expansion, and replacement.

This can matter when planning renovations involving existing building dimensions, additions, lot conditions, or uses.

At the same time, Philadelphia generally does not require a new zoning permit for alterations to an existing structure when the work does not change its area, height, floor area, or current legal use.

Before removing or substantially changing an existing portion of a property, its zoning status should therefore be understood.

Philadelphia's Older Homes Require an Existing-Building Approach

Philadelphia specifically has an Existing Building Code governing the repair, alteration, change of occupancy, addition, and relocation of existing buildings.

For qualifying detached one- and two-family dwellings and townhouses not more than three stories above grade, the City's code allows compliance through either the applicable existing-building provisions or the Philadelphia Residential Code, as specified by the code.

The Existing Building Code is intended to provide flexibility for work on existing structures while maintaining minimum requirements for public health and safety.

For homeowners renovating Philadelphia rowhomes, this makes documenting what exists before construction especially important.

What About Historic Philadelphia Properties?

If a property is individually designated historic or located within a Philadelphia historic district, additional requirements may apply.

The Philadelphia Historical Commission reviews work affecting designated historic properties. Generally, ordinary interior alterations do not require Historical Commission review unless the interior itself is specifically designated. Exterior alterations to designated historic properties, however, may require Commission approval.

Philadelphia's Historic Preservation Ordinance also regulates demolition of designated historic buildings and contributing buildings within historic districts.

Before demolition begins, owners should confirm whether their property is listed on the Philadelphia Register of Historic Places and whether the proposed work requires Historical Commission review.

So, What Does “Demo Strategically” Mean?

For a Philadelphia renovation, strategic demolition means determining the legal and physical status of the existing building before deciding what will be removed.

Before demolition, the project team should document existing conditions and determine:

  1. What is existing and intended to remain.

  2. What is being altered or replaced.

  3. Which existing conditions are legally established.

  4. Whether zoning nonconformities exist.

  5. Whether structural elements will be affected.

  6. Which permits are required for the proposed demolition and renovation.

  7. Whether the property is historically designated.

  8. Which portions of the project will be evaluated under current requirements once altered or reconstructed.

The goal is not to preserve something simply because it is old. The goal is to understand the regulatory status of the existing building before removing conditions that could potentially remain as part of a legal existing structure.

Before You Pick Up the Sledgehammer

In Philadelphia, demolition and design should be planned together.

The City's codes contain specific provisions for existing buildings, alterations, legally existing systems, zoning nonconformities, interior demolition, and historic properties. Removing an existing condition can change the scope of work that must be reviewed and reconstructed under the applicable codes.

For homeowners planning a renovation, addition, or major interior reconfiguration, documenting the existing house and establishing the demolition scope before construction begins can help ensure that the permit drawings accurately distinguish between existing-to-remain, demolition, and new work.

At Jane Draws Plans, we help Philadelphia homeowners document existing conditions and develop permit drawings for renovations, additions, and other residential projects before construction begins.

Philadelphia Sources

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