Accessory dwelling unit companies

Looking for accessory dwelling unit companies in Philadelphia, PA? Call AccessoryDwellingUnit Solutions for a contact a provider — no obligation. Licensed adu builders serve Philadelphia and the surrounding area, and you'll get straight answers on timing and what affects the price.

Last updated: September 24, 2026

What affects the price

Building an ADU involves several moving parts that shape your total budget. The biggest factor is whether you choose a prefabricated unit or a custom build on-site. Site preparation is also significant; if your land requires extensive grading, utility trenching, or foundation work, costs will climb. Your choice of finishes—like kitchen cabinetry, flooring, and siding materials—also shifts the bottom line. We help you navigate these variables to find a setup that fits your property. Exact pricing confirmed free on the call.

About this service

ADU companies offer end-to-end solutions, often handling everything from the first sketch to the final walk-through. You need these companies if you prefer a streamlined experience where one firm takes responsibility for design, permitting, and construction. They are ideal for homeowners who want to minimize the stress of managing multiple vendors and prefer a turnkey approach to adding a secondary residence to their property.

Frequently asked in Philadelphia

What are the disadvantages of ADUs in Philadelphia?

In Philadelphia, disadvantages can include navigating historic district regulations and potential challenges with parking in dense neighborhoods. Older properties might also require significant upgrades to utilities. Careful planning is needed to address these potential hurdles.

How much does an ADU cost in Philadelphia?

The cost of an ADU in Philadelphia varies based on its size, design complexity, and chosen materials. Factors such as foundation type, plumbing, electrical work, and any necessary demolition will impact the final price. A personalized quote will provide the most accurate cost estimate.

What are the rules for ADUs in Philadelphia?

Philadelphia has specific zoning ordinances that govern accessory dwelling units, often requiring them to be subordinate to the primary dwelling. Understanding lot coverage, setbacks, and permit requirements is vital for compliance. These rules are crucial for project approval.

Is an ADU allowed in Philadelphia?

Yes, Accessory Dwelling Units are allowed in Philadelphia under specific zoning regulations. The city permits ADUs, but homeowners must adhere to established rules regarding their size, placement, and integration with the main house. Checking your property's zoning is a key first step.

What are the rules for ADU in Pennsylvania?

Pennsylvania state law provides a general framework for ADUs, but detailed regulations are typically set at the municipal level, including in Philadelphia. Cities can define their own rules for size, setbacks, and permits. Consult Philadelphia's specific building and zoning codes for accurate guidance.

Also serving nearby: Trenton · Allentown · Reading · Elizabeth · Newark

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More on this: HUD ADU resources — ADU policy and financing research.

Service area details

1,550,542residents

11,540per sq mile

8ZIP codes served

Serving all of Philadelphia — population 1,550,542; about 11,540 residents per square mile across 134.4 sq mi. ZIP codes covered include 19019, 19092, 19093, 19099, 19101, 19102, 19103, 19104.

Neighborhoods served in Philadelphia: South Philadelphia, Fishtown, Germantown, University City, West Philadelphia, Manayunk — and every surrounding area.