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
This is a detached unit built on your property, separate from your main home. It is a practical solution if you have extra yard space and want to add living quarters for family, guests, or tenants. These structures offer privacy while keeping you close to your primary residence.
Frequently asked in Portsmouth
What are the options for an accessory dwelling unit for rent in Portsmouth?
What's the process for a prefabricated accessory dwelling unit in Portsmouth?
What are prefab ADUs in Portsmouth?
What's involved in accessory dwelling unit construction in Portsmouth?
Can I get 24-hour ADU services in Portsmouth?
How do I get an ADU quote in Portsmouth?
What if I need an emergency ADU 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, Downtown Portsmouth, Prentis Park, Cradock, Churchland — and every surrounding area.
Areas we serve
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