Last updated: September 24, 2026
What affects the price
Building an ADU involves several moving parts that shape your total investment. The final figure depends heavily on whether you choose a prefab unit or a custom build from the ground up. Site conditions are another major factor; if your property requires extensive grading, utility trenching, or foundation work, costs will climb. You also have to consider your choice of finishes, like high-end appliances or custom cabinetry. Navigating local permit fees and impact assessments also adds to the total.
About this service
Obtaining an ADU permit is the legal process of getting city approval for your secondary structure. You need this documentation before any construction begins to ensure your build meets local safety and zoning codes. The permitting phase can involve architectural plans and engineering reviews. Fees and design costs for this stage typically add several thousand dollars to your project. Exact pricing confirmed free on the call.
Frequently asked in Portsmouth
What is the cost of an accessory dwelling unit in Portsmouth?
What ADU services are available in Portsmouth?
Can I build an accessory dwelling unit for rental income in Portsmouth?
What are the building requirements for accessory dwelling units in Portsmouth?
What is the best ADU for my home in Portsmouth?
How do I find an ADU company in Portsmouth?
What are the advantages of accessory dwelling unit housing in Portsmouth?
Also serving nearby: Norfolk · Chesapeake · Hampton · Newport News · Virginia Beach
More on this: HUD ADU resources — ADU policy and financing research.
Service area details
Serving all of Portsmouth — population 96,793; about 2,906 residents per square mile across 33.3 sq mi. ZIP codes covered include 23701, 23702, 23703, 23704, 23705, 23707, 23708, 23709.
Neighborhoods served in Portsmouth: Olde Towne, Cradock, Churchland, Waterview, Downtown Portsmouth — and every surrounding area.
Areas we serve
Browse by state, then city.
