Number 1: Pellak Construction
on GoogleSpringfield Township, PA
Pellak Construction builds accessory dwelling units in Springfield Township, Pennsylvania.
(610) 819-4995 154 Saxer Ave, Springfield Township, PA 19064
ADU builders in Philadelphia
The 10 ADU builders from Google's results for Philadelphia, Pennsylvania, ordered by Google rating weighted by review count. No firm pays to be listed or ranked.
Last updated
- Garage conversion ADU
- $67,000 – $168,000existing structure
- Detached ADU
- $168,000 – $448,000new build, utilities
- Prefab ADU
- $134,500 – $336,000unit, foundation, install
- Philadelphia vs US
- +12%well above the US median
Licensing in Pennsylvania. Pennsylvania requires home improvement contractors to register with the Attorney General under HICPA. Philadelphia also licenses contractors.
Number 2: New Market Design + Build
on GooglePhiladelphia, PA
New Market Design + Build renovates and expands homes in the Philadelphia area. Its residential work covers additions, interior and exterior renovations, structural changes, custom finishes and fine woodworking, with homeowners, designers and the construction crew planning each project together.
(215) 248-1678 6650 Germantown Ave, Philadelphia, PA 19119
Number 3: Blog
on GooglePhiladelphia
Acorn Built Homes builds accessory dwelling units in the Pittsburgh area.
Number 4: Harth Builders
on GoogleLower Gwynedd Township, PA
Harth Builders builds accessory dwelling units in Lower Gwynedd Township, Pennsylvania.
(215) 654-0364 812 N Bethlehem Pike, Lower Gwynedd Township, PA 19002
Number 5: 3rd Story Philly
on GooglePhiladelphia, PA
A Philadelphia design-build contractor, 3rd Story Philly takes on renovations, home additions and new construction, with architects and designers on staff. Third-story additions are a core focus, and the firm also takes on kitchen remodels, decks and accessory dwelling units for city homes.
(215) 240-1587 40 W Evergreen Ave #104, Philadelphia, PA 19118
Number 6: Makara Builders
on GoogleGaithersburg, MD
Makara Builders, based in Montgomery County, Maryland, builds accessory dwelling units across Maryland, Washington, DC and Virginia. Homeowners use the units as home offices, homes for adult children or aging parents, or rentals, and the company first checks whether a given property can take an ADU.
(240) 599-5949 15800 Gaither Dr #210, Gaithersburg, MD 20877
Number 7: Pennsylvania Tiny Homes & ADUs
on GoogleCleveland, TN
Wind River Built constructs tiny homes and ADUs from its base in Cleveland, Tennessee, with homes placed in Indiana and other states. For Indiana builds, the company plans for climate control needs and offers deck additions and solar power options.
(423) 443-8166 970 Old Chattanooga Pike SW, Cleveland, TN 37311
Number 8: Ironstone Homes
Philadelphia
Ironstone Homes adds accessory dwelling units and in-law quarters to properties in the Lancaster area of Pennsylvania. The company plans these multigenerational spaces for aging parents, growing families or rental income, fitting each new unit into the existing home and lot.
Number 9: Home Addition Builders in Philadelphia
Philadelphia, PA
Myers Constructs builds home additions and accessory dwelling units in Philadelphia, Pennsylvania.
(215) 438-6696 70 E Coulter St, Philadelphia, PA 19144
Number 10: Accessory Dwelling Units
Philadelphia
This contractor builds accessory dwelling units for properties in the Philadelphia area.
What ADU builders charge in Philadelphia
In Philadelphia, a garage conversion ADU typically costs $67,000 – $168,000. Remodeling labor in Philadelphia runs about 12% above the US median, which accounts for most of the difference from the same project elsewhere.
How to choose between them
- Check the license yourself. Where Pennsylvania or Philadelphia licenses this work, the licensing board's own lookup confirms a license number in a minute. Do it before you sign, not after.
- Get three bids on the same scope. Written down, split into labor, materials, allowances and anything structural. Most people compare a total against a total and end up choosing between two different projects.
- Ask what is not included. Permits, debris removal, fixture and finish allowances, and repairs after demolition are the four that turn a cheap bid into an average one.
- Never pay a large deposit up front. A deposit to order materials and hold a start date is normal. Half the total before anyone shows up is not.
How this list is ordered
These are the firms from Google's results for "adu builders philadelphia", with directories, chains and suppliers removed. They are ordered by Google rating weighted by review count, and the ratings shown are Google's. No firm pays to be listed or ranked. The list was last updated in October 2026.
ADU builders in Philadelphia: common questions
Can I build an ADU on my lot?
It depends on your city and state. California, Oregon and Washington have state laws that make ADUs allowed on most single-family lots. Elsewhere it is set by local zoning, so check lot size, setback and owner-occupancy rules with your city first.