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
A modular unit is built in a factory and then transported to your property to be finished on a foundation. You should consider this if you want a faster construction timeline with less disruption to your daily life. It is an efficient way to add high-quality space to your lot.
Frequently asked in Richardson
What is a prefabricated accessory dwelling unit in Richardson?
Can I get an ADU unit built in Richardson?
What are the accessory dwelling unit permits needed in Richardson?
Are detached accessory dwelling units popular in Richardson?
Where can I find an ADU builder in Richardson?
What are accessory dwelling unit grants in Richardson?
What is involved in ADU building in Richardson?
Also serving nearby: Plano · Garland · Allen · Carrollton · Dallas
More on this: HUD ADU resources — ADU policy and financing research.
Service area details
Serving all of Richardson — population 117,435; about 4,111 residents per square mile across 28.6 sq mi. ZIP codes covered include 75080, 75081, 75082, 75083, 75085.
Neighborhoods served in Richardson: Galatyn Park, Haverford, Breckenridge, Spring Valley, Telecom Corridor — and every surrounding area.
Areas we serve
Browse by state, then city.
