Cost to build accessory dwelling unit in Missouri
Last updated: September 24, 2026
Considering an accessory dwelling unit in Missouri? We serve St. Louis, Independence, Lee's Summit, and more. Missouri has hot summers and cold winters. These weather extremes can impact building schedules and material choices.
Building an ADU in Missouri means planning for varied weather. Extreme heat and cold can affect construction timelines. Local rules in St. Louis and Independence are important. We help you navigate the permitting process.
Common questions
What is the cheapest way to build an ADU?
What does ADU stand for?
ADU stands for Accessory Dwelling Unit. It's a second, smaller home on your property. Think of it as a backyard cottage or garage apartment. These units add living space and value.
Are ADUs allowed in Missouri?
Yes, ADUs are permitted in many Missouri cities. Zoning laws can differ, especially in St. Louis. We help you understand local regulations. Many homeowners are adding ADUs for rental income or family.
What is the most expensive part of building an ADU?
Foundation work and structural framing are often the most costly. Plumbing and electrical hookups add significant expense. Labor costs and chosen finishes also influence the total price. We provide a clear quote for your project.
How much does it cost to build an ADU in St. Louis?
What is the cheapest way to build an ADU?
Useful reference: HUD ADU resources — ADU policy and financing research.