Cost to build accessory dwelling unit

Looking for cost to build accessory dwelling unit in Knoxville, TN? Call AccessoryDwellingUnit Experts for a contact a provider — no obligation. Licensed adu builders serve Knoxville and the surrounding area, and you'll get straight answers on timing and what affects the price.

Last updated: September 24, 2026

What affects the price

Building an ADU is a major project, and the final bill depends on a few key things. Site prep is a big factor; if your land is sloped or needs extensive utility connections, costs go up. The materials you choose—from siding to kitchen finishes—also change the math significantly. Whether you’re building a detached unit or converting an existing garage shifts the permit requirements and structural work needed. We provide exact pricing confirmed free on the call.

About this service

Building an ADU involves costs for permits, site prep, foundation, framing, plumbing, and electrical work. Prices fluctuate based on whether you choose a custom design or a pre-planned layout, as well as the complexity of connecting to existing city utilities. Exact pricing confirmed free on the call.

Frequently asked in Knoxville

What are the disadvantages of ADUs in Knoxville?

Potential disadvantages in Knoxville could include the upfront construction costs and the time it takes to navigate permits. Some homeowners worry about the impact on their existing yard space or privacy. However, understanding these challenges upfront with a professional can help you plan effectively.

How much does an ADU cost in Tennessee?

What are the rules for ADUs in Tennessee?

Can I build an ADU in my Knoxville neighborhood?

Most residential zones in Knoxville allow for ADUs, but specific requirements apply. These often relate to the size of the main house, the lot size, and how the ADU will be accessed. A consultation will clarify your neighborhood's specific allowances.

What's involved in getting an ADU permit in Knoxville?

Permitting typically involves submitting detailed architectural plans, site surveys, and proof of compliance with local building codes to the city. The process ensures the ADU is safe and meets all regulatory standards. Professionals can assist with preparing and submitting the necessary documentation.

What affects the ADU cost in Knoxville?

Key cost drivers for an ADU in Knoxville include site preparation, foundation work, the chosen materials for construction and finishes, and the complexity of plumbing and electrical hookups. The size and design of the ADU also play a major role. Get a personalized quote to understand your project's specific costs.

Also serving nearby: Asheville · Chattanooga · Murfreesboro · Roswell · Sandy Springs

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More on this: HUD ADU resources — ADU policy and financing research.

Service area details

198,162residents

2,007per sq mile

8ZIP codes served

Serving all of Knoxville — population 198,162; about 2,007 residents per square mile across 98.7 sq mi. ZIP codes covered include 37901, 37902, 37909, 37912, 37914, 37915, 37916, 37917.

Neighborhoods served in Knoxville: Downtown Knoxville, Old City, West Knoxville, South Knoxville, North Knoxville — and every surrounding area.