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Chattanooga, TN Accessory Structures: ADU Rules (2026)

Some Restrictions

Compiled from the official code textEditor Martyn O'NeillLast verified September 2026

ADU rules in Chattanooga, TN, also called accessory dwelling unit regulations or granny flat ordinances, cover setbacks, owner-occupancy, parking, and permit requirements.

Key Facts

Max size: 800 sq ft, detached or attached
Units per lot: one ADU per single-unit lot
Setback: 5 ft rear/interior side minimum
Max height: 24 ft for detached ADU
Parking: no extra parking required

ADU Eligibility Quick-Check

An Accessory Dwelling Unit (ADU) is a smaller, independent living unit on the same lot as a single-family home: converted garages, detached cottages, basement or attic conversions, and attached additions all qualify. Most states have streamlined ADU permitting since 2020, but local rules still control size, height, and setback.

Is your lot zoned single-family or multi-family residential?
Does your lot have at least 1,200 sq ft of buildable space?
Is your existing home owner-occupied (in most states this is not required, but some require it for ADU permits)?
Will the ADU stay under your state's size cap (commonly 850-1,200 sq ft for detached)?
Can you provide one off-street parking space (waived in many states within 0.5 mi of transit)?

If you answered 'yes' to most of these, you likely qualify in Tennessee under recent ADU streamlining laws. The Chattanooga, TN rules below cover local size, height, and setback requirements.

Summary

Chattanooga allows one accessory dwelling unit per single-unit detached lot, capped at 800 square feet, with detached ADUs limited to the rear or interior side yard and a maximum height of 24 feet.

Only one ADU is permitted per lot per single-unit detached dwelling. .....(3)The ADU must be owned by the same property owner(s) as the principal dwelling unit and cannot be subdivided or otherwise separated in ownership such that the ADU is located on a different lot than the principal dwelling unit. Under no circumstances may the ADU be converted to a horizontal ownership regime or a fee simple condo. .....(4)Maximum height for detached ADUs: .....(i)When the height of the principal dwelling unit is more than one-story: Maximum of 24 feet or two stories .....(ii)When the height of the principal dwelling unit is one-story: Maximum of 24 feet when measured to the peak of the roof for all roof types .....(5)Maximum height for attached ADUs: Limited to the maximum height of the zone and cannot exceed the height of the principal dwelling .....(6)Detached ADUs must be located in the rear or interior side yard only. Detached ADUs are not permitted in the front yard. .....(7)Attached ADUs must meet the minimum setback requirements as required for the principal structure in the zone. .....(8)The maximum size of a detached ADU cannot exceed a gross square footage of 800 square feet.

View official code

Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 40 Update 1).

Full Breakdown

Under Chattanooga's zoning code, an ADU must sit on the same lot as the principal single-unit detached dwelling and be owned by the same property owner: it cannot be sold off or converted to a separate condo. Only one ADU is allowed per lot. Detached ADUs are capped at 800 gross square feet, barred from the front yard, and must keep a 5-foot side and rear setback (10 feet on a corner side, 5 feet from an alley). Attached ADUs follow the underlying zone's normal setbacks for principal structures and are also capped at 800 square feet. No extra on-site parking is required for the ADU itself.

Violations & Fines

The Land Development Office enforces the zoning code and can seek an injunction or abatement through the City Attorney; violators are fined per offense, with each day a violation continues treated as a separate offense.

Frequently Asked Questions

Can I build a detached ADU in my front yard in Chattanooga?

No. Chattanooga's code bars detached ADUs from the front yard: they must sit in the rear or interior side yard, per Sec. 38-43(b)(6).

How big can a Chattanooga ADU be?

Up to 800 gross square feet, whether detached or attached, measured by exterior building dimensions, including any conditioned sleeping loft or stairwell.

Sources & Official References

[1]Chattanooga City Code Sec. 38-43(b) — Accessory Use Standards

Other rules in Chattanooga

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All Chattanooga rules

How Chattanooga compares: Easiest Cities to Build an ADU·Compare Chattanooga to another location·View the Tennessee accessory structures overview

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